Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Get all your technical information about electric bikes here.
User avatar
arthurtuxedo   100 W

100 W
Posts: 102
Joined: May 16 2017 11:45am
Location: San Francisco, CA

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by arthurtuxedo » Jan 23 2018 1:07pm

My 2 main concerns are that 1) I want the full 30 amps @ 36v when I venture into extremely hilly neighborhoods or pull a heavy load or passenger and 2) the converter doesn’t look like it’s remotely waterproof so I’d like to disconnect it on rainy days.

Sounds like my best bet is just to hook it up using connectors and take it off the bike when I don’t want the higher voltage, although it seems like a switch could work as long as I don’t expect it to be instantaneous. Maybe an on / off switch that’s mounted next to the converter on the downtube rather than on the handlebars.

You already answered my next question which is what the controller will do when it suddenly receives a different voltage.

Thank you both for the advice!

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jan 23 2018 1:26pm

1) When I run mine with a 36v battery pack, the converter routinely pulls 32+ amps of power from the battery or about 1250 watts. Since I'm running at 54V output, it delivers about 21 amps or around 1150 watts to the motor. So that is essentially the same amount of power (minus about 6-7% conversion loss) as the 36v at 30 amps.

2) If you are moderately handy, I think it would be pretty easy to put the booster in a waterproof or at least very water resistant enclosure. Of course, where and how you mount it will be important if the enclosure is only water resistant.

3) My booster is wired in with XT-60 connectors and bypassing it is as easy as swapping a few connectors around. So it may make sense for you to to mount the booster temporarily and see how different voltages affect performance. You may find that there is some compromise voltage between 36v and 72v that serves your needs well. I find that running at 54v works well for me. But then, I seldom want to go faster than 30 mph.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

Buk___   10 kW

10 kW
Posts: 750
Joined: Jul 28 2017 5:59pm

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an e

Post by Buk___ » Jan 25 2018 5:12am

wturber wrote:
Nov 07 2017 4:24pm
Buk___ wrote:
wturber wrote:So without doing some kind of modification, the converter interferes with using electrical motor braking.
I wonder if you couldn't use a pair of zener diodes and bypass link to feed the regen back to the batteries bypassing the converter; but I don't have enough electronics nounce to suggest a circuit.
I'd consider trying it if anybody can give specific circuit details.
It turns out there is a way to have your cake and eat it. Though it would mean moving to a different converter. The upside is regen braking and greater efficiency.

There's a type of converter called a split-pi topology converter that can convert up as well as down (like a buck-boost), but is inherently bi-directional.

So if you have it up-volting 36 to 48, when regen occurs it will convert the 48 from the 'output' side back to 36 at the 'input'.

I haven't found one to purchase yet :(

LewTwo   100 kW

100 kW
Posts: 1056
Joined: Apr 08 2014 4:46pm
Location: Houston, Texas
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an e

Post by LewTwo » Jan 25 2018 11:18am

Buk___ wrote:
Jan 25 2018 5:12am
I haven't found one to purchase yet :(
Minor technical issue ... I have the very same problem with dilithium crystals and neutronium.
The more I learn the more obvious the immensity of my ignorance becomes.
Weight Wennie E-Bike https://endless-sphere.com/forums/viewt ... 3#p1173723
Shaft Drive Grocery Getter https://endless-sphere.com/forums/viewt ... =6&t=90718
...and thanks to Justin!

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an e

Post by wturber » Jan 25 2018 11:45am

Buk___ wrote:
Jan 25 2018 5:12am

It turns out there is a way to have your cake and eat it. Though it would mean moving to a different converter. The upside is regen braking and greater efficiency.

There's a type of converter called a split-pi topology converter that can convert up as well as down (like a buck-boost), but is inherently bi-directional.

So if you have it up-volting 36 to 48, when regen occurs it will convert the 48 from the 'output' side back to 36 at the 'input'.

I haven't found one to purchase yet :(
Sounds great. But a quick look suggests that this is under a fairly new patent. So it seems unlikely that I'll see it in the needed under $100 price range before I have to buy new batteries. But I'll keep my eyes open.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

Buk___   10 kW

10 kW
Posts: 750
Joined: Jul 28 2017 5:59pm

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an e

Post by Buk___ » Jan 25 2018 1:40pm

wturber wrote:
Jan 25 2018 11:45am
Sounds great. But a quick look suggests that this is under a fairly new patent.
Three thoughts about the patent:

1. AFAICF, its only patented in GB.

2. It appears to be a highly contestable patent. People have apparently being combining boost converters with buck converters in a very similar arrangement for a long time; one way of looking at the circuit is that it is one phase of a standard(ish) 3-phase motor controller H-bridge; and there's a guy in AU who claims to have essentially identical circuits and working prototypes dating from 1992.

3. AFAIK, there is nothing to stop me or you creating our own personal versions, so long as we didn't try to market them commercially.

I'm currently looking into that possibility, but whether I'm up to the task time will tell.

wturber wrote:
Jan 25 2018 11:45am
So it seems unlikely that I'll see it in the needed under $100 price range before I have to buy new batteries. But I'll keep my eyes open.
Indeed, I found two sites offering them for sale -- one a licencee of the other -- and neither publish a price; which usually means they are milking it. I sent emails.

They both offer 60v/25A and 60V/75A versions that appear to be grossly over engineered, huge and heavy. The smaller is 50mm x 50mm x 328mm and 1.5kg.

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an e

Post by wturber » Jan 25 2018 2:15pm

Buk___ wrote:
Jan 25 2018 1:40pm

3. AFAIK, there is nothing to stop me or you creating our own personal versions, so long as we didn't try to market them commercially.

I'm currently looking into that possibility, but whether I'm up to the task time will tell.
Well, the thing stopping me is that it is too far out of my area of expertise. :D

I found one site offering two models. But the look and feel made me think it would be well over my $100 budget. And frankly, I'd have to think twice at $100.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
ngant17   100 mW

100 mW
Posts: 46
Joined: Jan 06 2018 8:28pm
Location: Chuluota, Florida
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by ngant17 » Jan 28 2018 11:36pm

I see you’re getting +22 watt-hours per mile, which jives pretty well with Luna Cycle’s standard 20 watt-hours/mile.

I have (2) 60v x 4Ah Li-ion batteries which is 480 watt/hrs. My latest test-run barely got me home with less than 10 mile range. So I’m really failing that standard by at least half.

I enjoy keeping it in a low gear ratio but I have a Shimano-Nexus 3-speed IGH sitting in a box ready to go on a rear bike wheel in a future project. Since I’ve been riding on a single-speed freewheel, do you think I would go further on these batteries with more gear selection?
Exitor Magna mountain bike, dual suspension
Bafang BBS02 motor 48V / 750W
stock Bafang 46T chainwheel / Shimano-Nexus 3-speed IGH
SRAM 1/2" x 1/8" single speed (PC1) chain
(1) Greenworks 60v 4aH battery (1) Echo 58v 4ah (as of Mar 2019)
Marine dual battery switch
"If my ̶w̶h̶e̶e̶l̶s̶ blades ain't turning, I ain't earning!"

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jan 29 2018 12:47am

ngant17 wrote:
Jan 28 2018 11:36pm
I see you’re getting +22 watt-hours per mile, which jives pretty well with Luna Cycle’s standard 20 watt-hours/mile.

I have (2) 60v x 4Ah Li-ion batteries which is 480 watt/hrs. My latest test-run barely got me home with less than 10 mile range. So I’m really failing that standard by at least half.

I enjoy keeping it in a low gear ratio but I have a Shimano-Nexus 3-speed IGH sitting in a box ready to go on a rear bike wheel in a future project. Since I’ve been riding on a single-speed freewheel, do you think I would go further on these batteries with more gear selection?
So you only have one gear? If so, then yes, adding some gears might help. I basically use maybe three gears when riding. On for starting from a stop. One for medium cruising (20 mph or so) and another for faster cruising (25 mph or so). I'm not so sure an internal gear hub is the right way to go though. A freewheel and derailer are more efficient and probably more durable. And even a cheap five speed has the bonus of providing a seldom used "granny" gear for hills or other difficult situation.

Here are some some other thoughts. Others who know more about mid-drives might have some more useful insights.

1) Each of your packs is probably a 15s 2p 18650 pack. It really isn't a 60v pack. It's probably a 55.5v pack (15 x 3.7v). 3.7v is the approximate average voltage as a pack discharges from 4.2v per cell down to something around 3.4v per cell. I think Greenworks is taking a value of 4v cell and multiplying that by 15 to get the 60v. It's a marketing gimmick (note that they say 60v Max) that uses a voltage close to the peak cell charge voltage (usually 4.2v for 18650 lithium cells) instead of the average voltage. Your total capacity is probably closer to 440 watt hours. Maybe even less if the official charger doesn't charge to 4.2 volts/cell. I've found ads that spec. 216 watt hours/pack.

2) If my guess is right about the pack configuration, then you only have 2 cells in parallel for each pack. I'm assuming you are running both packs in parallel. If so, you only have four cells in parallel over which to spread the current draw. That's not very many and might be straining the cells and reducing efficiency. If your controller is actually pulling more than 750 watts, that could be a huge strain. Have you measured your peak current draw? If you are running one pack at a time and switching, thing are even worse. Do your packs get warm when you are riding?

I'm running seven 2p packs in parallel. My 1250 or so peak watts (35 peak amps) is being drawn across 14 total cells. That means each cell experiences significantly less stress (current draw). My packs never even get mildly warm. They aren't operating at optimal efficiency, but they aren't too far off from what the manufacturer's spec sheet uses for calculating capacity.

3) I don't know what kind of low voltage cut-off the BMS in these packs have. They might be very conservative in order to help the batteries have a long life. You might do a slow 10 watt or so drain test on one of these packs (I've used a couple halogen lamps) with a current measuring device attached and see what the actual pack capacity is.

4) I don't know how you are riding. Is it fast or slow? Do you accelerate really fast a lot? Are you pedaling a lot to help out, or letting the motor do all the work? How you ride matters.

Anyway, those are my thoughts. If you had four packs in parallel, I think your overall efficiency would improve.

FWIW, I did a long (40 mile)ride today with the idea to be miserly on power usage. I kept the PAS in 1 or 2 mode most of the time and kept my typical speed at 20 mph or less. I averaged about 13.5 watt hours/mile. Far better than I get with my faster and more aggressive riding on my commute. How you ride makes a bid difference.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
ngant17   100 mW

100 mW
Posts: 46
Joined: Jan 06 2018 8:28pm
Location: Chuluota, Florida
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by ngant17 » Jan 29 2018 6:42pm

Thanks for your input. Will be studying them carefully to improve bike performance.

“1) Each of your packs is probably a 15s 2p 18650 pack. It really isn't a 60v pack. “

I can charge the batteries overnight, and VOM shows 62-64v right off a fresh charge. VOM is accurate, so I think it’s a real 60v battery.

I guess I could take a torx screwdriver and pop open the battery casing to look closer at individual cells inside. Will put that on the to-do list.

“Have you measured your peak current draw?”

No, I will have to plan to check amps with the VOM.

“If you are running one pack at a time and switching, thing are even worse. Do your packs get warm when you are riding?”

I stop and plug in the 2nd battery when first one goes dead. Pedal-only mode on this fixed gear bike is an uphill battle and I’m on flat streets most of the time. Don’t think I have temp issue with batteries, they have no stamina going long enough to overheat.

I have a 30T/22T Bafang chainring upgrade coming soon, need a decent granny gear.. And if that doesn’t cut it, probably will take your advice and go IGH. 23T is ready to go on the Nexus Shimano IGH. I will have to order a 24in 32H rim with spokes to lace in the Nexus-Shimano 3-speed hub. Got a book to study that.

Philosophically thinking, it seems not a good idea for me to match a high-speed electric motor with a traditional bike chain derailer, IMHO one wasn’t really designed for the other. I don’t trust a moveable chain going super-fast and slithering up and down on all those different spockets. Something’s going to give out, too many parts for murphy’s law to effect.

Believe me, I already have enough hassles with chains, cutting lawns with a McLane reel mower, it’s also single speed. I just want that #41 chain running on its sprocket and to stay there, otherwise I’m DOA on a lawn and can’t mow. If my blades aren’t turning, I’m not earning. This work’s a one-man show and I just can’t afford the down time. Master links fall apart, the chain gets loose and runs off sprocket, you name it. Been there, done that, got the greasy t-shirt.

But I digress. As it stands now, I can barely pedal on my own outside of PAS 1. Bafang takes control 99% of time.

I may end up using these batteries as emergency spares once I decide to get a real Li-ion battery. Down the road a ways. I still maintain the Bafang BBS02 can handle a 60v battery. Based on my experience, the threshold for shutdown mode on this Bafang controller is 61.5v. Still looking for a good buck converter which I won’t short-circuit on install.

I will be adding accessory devices to drain down from 62v full charge– lights, phone charger, anything to do the trick. Haven’t fried the Bafang and want to keep it that way.
Exitor Magna mountain bike, dual suspension
Bafang BBS02 motor 48V / 750W
stock Bafang 46T chainwheel / Shimano-Nexus 3-speed IGH
SRAM 1/2" x 1/8" single speed (PC1) chain
(1) Greenworks 60v 4aH battery (1) Echo 58v 4ah (as of Mar 2019)
Marine dual battery switch
"If my ̶w̶h̶e̶e̶l̶s̶ blades ain't turning, I ain't earning!"

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jan 30 2018 4:35pm

I'm no expert on mid-drives, but your thinking on derailer systems seems flawed since most mid-drives are designed to work with pedals and rear drive on a standard bike at standard pedaling speeds. But maybe I'm wrong. And if so, then I'd think using an IGH (which I did not recommend) would be undesirable for the same basic reasons. As it stands, my understanding is that they are not as durable and are sensitive to shock loads. But I'm no expert there either. I'd search this forum for more info.

A nominal 56v battery will read have about 63 volts when full charged. In the context of consumer power tools, calling the batteries "60 volt Max" is barely even a white lie. But in the context of e-bikes, it would be deceitful to market that battery as such. The standard is to use an average voltage - usually 3.7 volts per cell or cell parallel group. That's why it is a 56 volt battery and has a bit less stored watt hours than you calculated.

I'd try running the two packs in parallel to see if your range improves
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Feb 07 2018 12:09am

I'm going to be off the bike for 3-4 weeks (or more) following an upcoming surgery, so I took the opportunity this weekend to get in a couple of decent rides. Saturday was my regular commute, but I had a table tennis club board meeting about 8 miles away. So I rode to that as well. Google Maps was a great help in scouting the route. The total trip length was 48 miles. That was my longest trip without recharging to date. My battery is 7 of those 36 volt 4.4 AH LG battery packs I got from ebay.

My calculations and ending voltage showed I had plenty of reserve, so I decided to take a slightly longer scenic ride on Sunday that would include more hills. The plan was to ride from Fountain Hills to the Saguaro Lake Marina and then back home. But I didn't want to return by the same route. I wanted to take the Bush Highway east and circle around the Salt River. The problem was in how to get back across the Salt River and onto the Beeline Highway (SR 87). There aren't a lot of public bridges in the area. So back to Google Maps. They showed a nice way back that was only about 30 miles. The trip up was about 20. So fifty miles total. No problem.

I left at 1:30P, taking Shea Blvd to the Beeline Hwy. The Beeline has a wide shoulder that is almost as wide as a full car lane. That makes up a bit for the cars whizzing by at 65-70 mph. But there weren't a lot of cars. People were already getting their Super Bowl parties underway. I had the DVR set to record the game for later viewing and was expecting largely empty streets on my return ride home since that would be when the game was well under way.

The ride to Saguaro Lake was nice and uneventful. I cruised the marina a bit. Rested. Had a snack. Took a few photos. And headed out to circle back home on the 30 mile leg.
saguaroLake.jpg
saguaroLake.jpg (87.28 KiB) Viewed 1841 times
It was nice when I finally hit Spook Hill. I'd last ridden up that hill 20 some years ago at about the 90 mile mark of a century ride on my good ol' Trek 1400 (no motor, of course). That was a tough climb back then after riding 90 miles or so. With the e-bike, I cruised up at 10 mph with minimal effort. Nice.

It turned out that the crossover road Google was sending me down was actually a private road that went through the Salt River Pima Sand and Gravel operations. About a mile into it, it became clear that they really didn't want any non-construction vehicles trespassers going through their operations. I decided it was best not to test their promise to prosecute. The alternate route was going to add about six miles to my trip. With my two mile detour down the sand and gravel road , my route was now about eight miles longer than planned. But I figured I should still have plenty of battery.

So using a now corrected Google Map route, I finally got back to Fountain Hills a little after 5PM. I stopped for a snack (tea and cookies) at the Circle K and headed home feeling pretty good - probably a bit too good. Heading home it was like riding through a ghost town. The streets were empty. But I did hear a loud cheer as I rode past the All American Sports Grill. I figured I still had plenty of battery and cruised pretty fast on the empty but mostly uphill streets home. That was a minor mistake. My batteries ran out about a half mile from home. The BMS's on the packs did their jobs and stopped the batteries dead. They wouldn't let the packs discharge beyond 31 volts or so. The last half mile was all human bean power ... uphill.

In the end, the trip was about 58 miles. I think this was the first time I had ever completely discharged this battery as a group of seven packs. The full recharge consumed 28.5 AH of charge - a bit less than the calculated 30.8 AH. If I use an AH capacity based on the recharge, my average WH/mile was 17.87. My typical traveling speed on the first leg was steady at around 20 mph. But I rode between 20 and 25 mph most of the time on the last part of the trip home. I'm pretty sure I used a lot more battery power per mile on the last part of the trip home - especially after the Circle K stop. So if I take my time and limit my speed to less than 25 mph, the battery as configured has about a 60 mile range or about 7.5 miles per pack.

Links to the SportsTrackLive tracks of the trip:
http://www.sportstracklive.com/track/de ... ke/2406281
http://www.sportstracklive.com/track/de ... ke/2406282
http://www.sportstracklive.com/track/de ... ke/2406284
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

markz   100 GW

100 GW
Posts: 6591
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by markz » Apr 10 2018 5:19pm

ngant17 wrote:
Jan 28 2018 11:36pm

I enjoy keeping it in a low gear ratio but I have a Shimano-Nexus 3-speed IGH sitting in a box ready to go on a rear bike wheel in a future project. Since I’ve been riding on a single-speed freewheel, do you think I would go further on these batteries with more gear selection?
How much did you pay for that Shimano Nexus 3 speed IGH?

I say you need gears when your riding a hub motor, it doesnt have to be much, but I'd say if you have a direct drive hub motor then its wise to have a gear with lots of teeth on it so you can help the motor and save battery juice while climbing a hill, and if you ever run out of battery juice, then you can comfortably ride with a small crank gear and a large rear gear.

I myself have ran out of juice on my mxus 3kw and had to ride home with a bad gear ratio, its not fun!

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » May 15 2018 4:51pm

So the 3-4 weeks off the bike turned into three months. The doc wanted to err on the side of caution. In the meantime I had been thinking about actually properly mounting my batteries. Having them all bungeed in a soft bag certainly worked for over 1500 miles, but it wasn't very tidy even though I had things well packed and padded. It seemed a poor long term solution. So it seemed like a good idea to do this upgrade before I started riding again.

Fry's electronics had these black plastic "pistol cases" on sale for about $15 each. The inside dimensions would allow one case to hold four of my 36v 4.4 ah ebay packs with easy room for wiring. So I got two and spent this last Sunday working out a mounting system and getting them wired in.

Each pack weighs about 2.2 lbs as I recall. So the whole assembly with cases and wires is probably right around 20 lbs.
It definitely gives the bike more of a "motorcycle" look - which is not a good thing IMO. However, they seem very sturdy and the mounting is very secure. I noticed no rattles, wobbles or other problems on my commute in to work this morning. Everything seems very solid.

With eight packs and (about 1250 WH), my range should be 50-60 miles (I've actually done 50 with 7 packs), almost double my daily commute. So that means the batteries won't be stressed much day-to-day.
IMG_20180514_010710866_LL_SM.jpg
IMG_20180514_010710866_LL_SM.jpg (222.5 KiB) Viewed 1487 times
IMG_20180514_010818263_LL_SM.jpg
IMG_20180514_010818263_LL_SM.jpg (178.79 KiB) Viewed 1487 times
IMG_20180514_010811045_SM.jpg
IMG_20180514_010811045_SM.jpg (174.27 KiB) Viewed 1487 times
IMG_20180514_011136619_SM.jpg
IMG_20180514_011136619_SM.jpg (159.33 KiB) Viewed 1487 times
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jun 03 2018 5:41pm

Commuted home for the first time in over 100 deg F weather at about 5:30P. Booster fan still hasn't come on. Temp of booster fins and side cover were only slightly higher than ambient. Battery cases are black and the back portion was about 117 deg F from the sun. The cases don't insulate in any meaningful way, so that heat is being transmitted into the case. This could be an issue if I ride in daylight on hot days. Most of my commuting will be mornings and near or after sundown. I might want to create a simple light colored cloth cover if I ride any substantial distance during hot summer days.

Motor case was about 127 deg F on the hottest portion. That doesn't seem horrible given an outside temp of 100 or so.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

Bg-electric-cycle   100 mW

100 mW
Posts: 38
Joined: Jun 06 2018 7:08am
Location: Yambol

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by Bg-electric-cycle » Jun 08 2018 7:49am

Wturber awesome integration of the batteries could I show those photographs to a mechanical engineer. I require something similar.

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jun 08 2018 9:03am

Bg-electric-cycle wrote:
Jun 08 2018 7:49am
Wturber awesome integration of the batteries could I show those photographs to a mechanical engineer. I require something similar.
Sure. It's a public forum after all. I can't see why an engineer would care though.

Here's a peek inside one of the cases.

IMG_20180520_093519840_HDR_SM.jpg
IMG_20180520_093519840_HDR_SM.jpg (180.81 KiB) Viewed 1308 times
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

Bg-electric-cycle   100 mW

100 mW
Posts: 38
Joined: Jun 06 2018 7:08am
Location: Yambol

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by Bg-electric-cycle » Jun 12 2018 11:30pm

Brilliant, thanks.

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jun 19 2018 4:45am

While some people are spending their time on mundane things such as trekking across the globe to tour Europe and Asia on solar powered bikes, I turned my attention this weekend to a truly exciting project - rear rack reinforcement.

Since I've I've cleared off space on the top of my rack by putting my batteries in two side cases, it got me thinking about future uses of that space. Maybe it would be extra batteries, charger, or other supplies for long trips. Maybe it would be a fancy milk crate for exciting grocery store runs. The possibilities are almost endless. But are my previous reinforcements strong enough or am I flirting with disaster?

Those supports consisted of adding a wood plywood insert in the main cantilever beam and two aluminum bars that connect the cantilever beam to the top of the seat stays increasing rigidity and reducing some of the bending load on the seatpost. The wood in the beam not only makes that beam stronger, but it better distributes the loads imposed by the various bolts that now pierce that beam to connect the controller and the first set of support bars. I've I added a wood insert to the seat post as well as a failsafe against seat post breakage. But it seemed to me that the end of the rack could use some support. It is still cantilevered quite a bit. So the plan was to run a support from the back end of the rack to the seat stays down near the dropouts.

Welding or brazing aren't options for me. So it had to be a bolt 'er up affair. I decided to use round aluminum tube with flattened ends. Once flattened, I could more easily drill a hole and bolt the tube to the rack and to the tube clamps. I flattened the ends in a bench vice using some thick weight lifting belt leather as a cushion in order to get a smooth transition from the flat to the round tube and hopefully not introduce stress risers there. The tube clamps (from House Tuning on Amazon) are a bit bulky, but they are light and rigid. These clamps attach to the seat stays at different points due to differences in the braze-ons on each side. I went with large 5/16 diameter bolts because I'm not sure what the aluminum grade is and I wanted more bolt surface to accept the load. Best case is that the tubing is 6063 T5. Worst case is that it is much softer. This should increase the rack's load carrying capacity a bit. Though after finishing I realized that I could make the whole assembly more rigid and stronger by running some tubes from the clamps and up to where the aluminum bars attach to the rack. That would not only increase the amount of direct support, but it would triangulate the structure making it very rigid.

Stay tuned for a possible fender installation project coming soon ... for a Phoenix area bike?!? Is it worth it? Am I over-reacting to this last weekend's rain? And how cool would it be to have them colored yellow!! The excitement never ends.

Anyway, best of luck to the Sun Trippers. I'm sorry that your little trip might distract you from fully appreciating this project of mine.


TopAttach.jpg
LightClamp.jpg
LightClamp.jpg (231.8 KiB) Viewed 1225 times
FullSupport.jpg
FullSupport.jpg (236.76 KiB) Viewed 1225 times
Last edited by wturber on Jul 06 2018 10:41pm, edited 4 times in total.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jul 06 2018 10:30pm

Taking a page from the "If a Little is Good, then Too Much Should Be Just Right" book, I added a third strut to make my rack support fully triangulated. I increased the size of the bolts that secure my 20 lbs of battery to the rack (not shown) to 1/4" diameter and added more fusible silicone tape between the batter mounts and racks to provide some cushion between the two. Everything rides and feels super solid and quiet now.
fullyTriangulated_SM.jpg
fullyTriangulated_SM.jpg (156.52 KiB) Viewed 1161 times
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jul 22 2018 10:49pm

So, Friday last week I crossed the 3000 mile point with my e-bike. I was pretty happy with how things have gone and how reliable the bike had been. It had even managed to go through some relatively rare wet weather the Wednesday before from one of our early monsoons with no problem. So I was a bit bummed when the things went a bit sideways on Saturday afternoon when I headed toward the studio after playing some table tennis.

But first a little 3000 mile report before the problem.

The cheap wheel with over-gauged spokes that came with the ebay kit seems as good as new. No loose spokes. No broken spokes. Spins at true as the day I got it. That said, it was never perfectly centered around the hub and still isn't. I moved the cheap Chinese tire from the back to the front and put a 2 inch RiBMo tire on the back. I've found that running the RiBMoWhen I did that I found out the the front knobby that never had a flat also had tire liner. So I figured that was why it never got a flat and kept it for the cheap Chinese tire. After 3000 miles, still no flat on the front. The back tire hasn't had a flat until last night. Go figure. But I'll cover that in another post.

I also got tired of the XT60s sparking, so I replaced the main power connector with a spark arresting XT90. Which brings be to the booster failure.

Yep. The booster went kaput. It got me to the Via Linda Senior Center just fine in the morning to play some table tennis. But at about 2:30P I was setting out for the studio when the bike started to go and then faultered. I double-checked the XT90 plug and say that it was not fully seated. So I went to seat it and it was hotter than heck. So I unplugged it. My assumption was that not being fully seated, perhaps it was arcing. So I let it rest for a minute before plugging it back in. When I did that, the fuses on the booster popped loudly. One quite dramatically with black smoke and all that good stuff.

Without going into the details, I determined the cause was the booster (not the motor, controller, or watt meter) and bypassed it. So now I had about 40.2 volts for a 48v system that has a low voltage cut-off set to 39 volts. With my travel plans now changed for home, I had about 1.2 volts of discharge to play with while going 10 miles mostly uphill. I put the bike on PAS-1 and headed home. PAS-1 is probably just enough power to make up for the direct drive motor cogging and perhaps compensated for the fact that the bike weighs about 65 lbs. I limped home at about 10 mph - about half my typical speed. It was about 90 degrees and super humid because one of our monsoons was passing nearby. So even though I wasn't really hot, I was quite literally dripping sweat all the way home. It was like it was raining from me.

When I got home I checked the booster to see if there was a dead short and there wasn't. After replacing the fuses, I plugged another battery in (protecting it with a 10A fuse first) and the 10A protective fuse blew immediately. Nothing other than the blown fuses is seems visually wrong with the booster other than one output capacitor is slightly domed. For all I know, it has always been that way.

So I ordered a replacement booster and the system is all back together. Unfortunately, the replacement booster is only pulling about 950 watts. The other would do 1050 to 1100 watts. That's not a big difference, but It does mean that with the controller set at 80%, it will now cut out on full throttle. So its a bit annoying. I need to either reduce the controller to 70%, figure out why the new booster is underperforming, or fix the old booster.

I'd like to figure out why the old booster failed and more importantly, what failed on it. If I can identify the part that failed, perhaps I can replace it. It is interesting that this coincided with all the extra water and humidity we've been having, but it seems unlikely that the booster was wet when it blew. The only way that would be possible would be if the water resistant enclosure encouraged condensation and the condensation caused a short. I don't see how the XT90 or new watt meter could have caused the problem.

I've been considering some long distance cycling and certainly wouldn't want this kind of failure on the road. So I'm figuring that I will replace my current controller with one designed to operate at 36 or 48 volts. That way if the booster fails I can ride with a minor loss of top speed, but still pull full watts for going up hills and such. The other options would be to replace/rewire the batteries to 48 volts - which is too expensive and/or too much work or to carry an extra booster. Frankly, I'd rather carry an extra motor controller.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jul 22 2018 11:01pm

So my current big question is why the new booster doesn't provide as much current. I notice that the three output capacitors are shorter and rated at 470 ufd while the other booster had taller capacitors rated at 680 ufd. I can see the watts sometimes peak momentarily to over 1000 watts before the booster voltage drops dramatically and the motor controller cuts out. So I wonder whether the smaller capacitors simply can't handle the abrupt increases in power draw?

The boosters are adjustable to limit current output and I have that pot trimmed to the max. When I measure the resistance across that pot, I see 4.74 kohms. The pot is nominally 5kohms. The trim pot on the blown booster measures 4.92 kohms. Is it possible that this failure to reach 5 kohms is limiting the output? If so, I'd be willing to replace that component. Also, I'd be willing and I think able to replace the output capacitors.
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
wturber   100 kW

100 kW
Posts: 1483
Joined: Aug 23 2017 8:52pm
Location: Fountain Hills,AZ
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by wturber » Jul 22 2018 11:32pm

Now to the new flat tire. I was at first very happy that the Slime I had in the tube appeared to be doing its job. Even though the tire was losing air, re-pumping it twice in 16 miles got me home OK. So no roadside repair needed on a hot summer evening. But when I took the tire apart this morning I found that the tire was filed with slime juice and that the slime hadn't appeared to seal the hole at all. The nature of the puncture was simply that intruding staple also acted a bit like a plug. It was simply a slow leak. All the Slime did was make a mess. It had filled the tire with its juice. When I removed the inner tube, it was quite literally dripping with Slime juice. That would have been a real pain to deal with during a roadside repair.

So this appeared at first to be a failure of the tire liner. But that wasn't really the case. I could see where the tire liner had saved me from two staples. There are two sets of brown dents that are pretty clearly from two different staples. But the staples did not penetrate. But somehow, the tire liner has slipped while installed and had doubled over on itself. I'm having a hard time imagining how, but that's clearly what I found. The staple that punctured the tube was not inhibited by the tire liner. The tire liners clearly help, at least if they are in place to do so. So I've reinstalled the (cleaned) liner using some 1" gorilla tape and rubber cement to help keep it in place. But I'm seriously thinking about cannibalizing the cheap Chinese front tire and pressing it into service inside the RiBMo tire as a thicker liner as Chalo outlined in another post. I already have a front tire replacement waiting since I didn't expect the cheap Chinese tire to last this long. But that cheap Chinese tire is doing pretty well and is still going strong after 3000 miles. I kinda hate to kill it.

StaplePunctureSM.jpg
"Commuter - DC Booster"
Iron Horse 3.0 hardtail - 48V / 1000W / 470rpm generic Chinese DD Hub motor (ebay)
8 x 36v 4.3ah 10s 2P battery packs - 1500W 30A DC Boost Converter delivers 54v and about 1000 watts peak
53T/42T Sakae Road cranks - 30mph+ on flats
viewtopic.php?f=2&t=90369

User avatar
amberwolf   100 GW

100 GW
Posts: 26004
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by amberwolf » Jul 23 2018 3:42am

Regarding tire liners:

I only have experience with the Slime brand ones.

What I usually see with them is that over time, they move around in the tire, creeping up the sidewall of one side in one area, and up the sidewall of the other side in a different area, so they end up kinda like a squiggle roughly centered on the tread area, and don't actually protect you from flats very well.

This happens more often and is worse the lower the tire pressure is, and the wider the tire is.

The narrower the tire and the higher the pressure, the less of a problem it is.

Heat makes some difference too--the plastic of the strips deforms easier the hotter it is. When I used to ride regular bikes, the liners would be ok in the winter, and mostly in the spring and fall, but in the summer they'd have to be realigned sometimes. If they got too distorted I'd have to get new ones cuz they wouldn't straighten out. I'd know when this was necessary because I'd get flats or slow leaks. :(

After realizing the pattern I would check them in various conditions and find them straight until temps started staying over 100F+ much of the day.

Riding with just me on there it wasn't as big a problem, especially back when I only weighed 120lbs or so. If I carried cargo regularly when ti was that hot, it got to be more of a problem.


What I do now when I use them is use the liners between an old thickwall tube that's slit along it's inner circumference, and the tire. The actual inflated tube goes inside the slit tube. It doesn't seem to make that much difference to the squiggle problem, but it does keep the liners from ever cutting into the actual tube (which is an occasional problem), and it adds one more layer of flat protection for short objects.



One thing you *don't* want to do is glue the liners down. If they are fixed to the inner surface of the tire, then they won't move to let stuff slide across their surfaces and deflect the points away from the tube, or let them push inward, and the stuff will instead puncture the liner and your tube.

I know this because I tried adhesives including flexible silicone to glue the liner to the tire, and that's the only time I ever had punctures of the liners themselves (except for once when I had no choice but to ride thru a bunch of roofing nails falling out of a truck further up the road--Slime did replace the liners and the tubes when those nails went thru, per their guarantee, but I still had to deal with the flats in the heat at the time).
Last edited by amberwolf on Jul 23 2018 4:05am, edited 1 time in total.

User avatar
amberwolf   100 GW

100 GW
Posts: 26004
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Using the Wangdd22 1500W 30A DC Boost Converter on an ebike

Post by amberwolf » Jul 23 2018 3:56am

Regarding the dead converter:

If there are any caps that appear swollen, then they need to be replaced; they're not capable of their jobs any mroe. It's also possible that all of the caps on the board are bad, too, even if they aren't swollen. If you have a capacitor tester you could test them before replacing them, but it's probably easier to just replace them.

If the caps failed, then circuits they are part of may have experienced overcurrents or overvoltages, and could have other damaged parts. Replacing the caps will not fix the device if this is the case, but you have to replace the caps to test this (unless you test all the potential-failure components).

Most commonly, caps fail internally shorted, so caps acxross the input could cause fuses to blow. But so could switching FETs on the input side, if there are caps that failed and caused high enough currents thru them, or failed to filter out voltage spikes that then exceeded FET (or other active component) specs.

Still, it's worth a shot to replace the caps and see what happens.

There are also a number of good posts by Dnmun over the years, about fixing chargers, which are also SMPS like these boost converters, and the basic testing/troubleshooting you could do if replacing caps doesn't do it.

Post Reply