My kick scooter project

[E-ScooterDude]

More great info! Thanks guys.

You are making me want to go with a 60V system. I agree about getting more controller than I currently need so as to not have as many old parts laying around over time. I too can see myself getting dissatisfied with a marginal system in a short time.

The deck is ABS and it’s not sealed. I am a decent wood worker so I’m going to make a nice deck out of maple and put some anti-skid strips on it for the same reasons you mentioned. Sealing it is a great idea.

The controller is still being mounted on the plate in the battery box, but they are not double-side taped anymore and are bolted directly to the plate. There is some ventilation but I was planning on mounting the new controller (if it will fit) to this plate and set up forced ventilation fan and vents for cooling. I am reluctant to remove the plate because it seems to provide support for the steering column. I also want to keep the battery box “clean”. I have been thinking about fans and filtered outside air intake and exhaust for the whole battery box.

I could run the 48V/1600W BOMA but I had intended to replace the motor with a higher quality one. I believe there are a lot of good options out there and I’d like to move to those with the other upgrades. I’m willing to compromise on speed to get range so the motor doesn’t have to be a monster.

Drive system upgrade: all 219 parts, no brainer.

About home building: I know that the cost is higher, but I'd really like to go with off-the-shelf parts as much as possible, the challenge is to mix and match a good set that will meet my needs. I don't really want to build battery packs and rewind motors, but I do want to "hot rod" the scooter and I believe I can do that with pre-made parts, although it might not be as much fun as a more home-grown system. Time will tell if I change my mind and start going more custom.

So, for now, I’d still like to confine my work to the battery box, so I propose a new plan……….
1. Controller upgrade: same Kelly as E-God, it’s proven and will more than meet my needs; that does have value to me.
2. Battery upgrade: I believe I can have it built to my specs but I’ll have to find out, there is also a ready-made pack available that is 60V/40A, 20Ah, 13S9P, 18650 (probably Panasonic) NCA. I don’t have as much confidence in this battery as the other but I’m just looking at options for now.
3. Motor upgrade: I’d like to stay with the 48V Golden Motor and send it 60V vs. 50V. I looked at the LightningRods motor, but they offer so little in the way of product information. I may have to ask them direct questions. E-God’s experience with it does help and I consider it a good option.

I’m curious to see what will come from my custom battery idea and I’ll post that when I get it.

Thanks for the help to all who offer it.

 

[E-ScooterDude]

I’ve started my own thread under “My E-Scooter Upgrade Project”.

The calculations, measurements, research, and vendor quotes are done. Here’s where I am: I’m going with 72V in DIY 20S2P packs. DIY was the only way to go to get exactly what I want and keep costs reasonable. I’ve also got ideas for what I think may be a good “outrigger” battery, but it’s totally theoretical at this point.

E-God, would you please pass along your recommendations for 20S BMS and charging setups?

Thanks,

 

[ElectricGod]

Skip the ventilation system. It's not needed and you have everything inside a nice steel box/giant heatsink...use it. My batteries never get warm enough to call them dangerously hot and the motor controller mounts flat to a wall with heatsink compound behind it. The battery box is my heatsink. The area where the controller is bolted down, gets a little warmer than air temperature, but not by much. Outside invasions into your battery box for ventilation is just asking for water and dirt to have a new way into the box. You don't need it. Just use the box as your heatsink like I am here.

I think that's what my deck was too...ABS. I replaced it days after getting the scooter. It truely was a POS. Even a cheap wood lid would have been better.

That plate doesn't support anything, just remove it. If you are worried about the frame bending along the flat part at the front of the battery box, well look in my thread somewhere in the last few pages. Mine did that, but then I'm running a lot more power than you are and so the leverage on the handle bars to keep me on the scooter is fairly significant. I added a couple of pieces of square tube under there to stiffen it up and that problem is now solved and the whole battery bay is still opened up. I know my battery bay is a nest of wires and it could be cleaned up significantly, but it's normally all hidden where no one but me sees it so I don't care overly much.

Motors...I weigh 240 pounds and my scooter weighs something like 120 pounds so I want a motor that can pull all of that around, climb hills, accelerate well and get me going quickly. A low wattage motor (1500 watts) wont do that for me. At a stop light, I don't kick off, I just step on and hit the throttle. The motor is strong enough to push me off from a dead stop. The 2000 watt BOMA could just barely do it. The 1500 watt...never. Whatever you do, don't go the bafang route. Those motors are crap and their wattage is way inflated. The big block is a great choice...one of my favorite choices in fact. An outrunner with 50-150kv works well. The 80-100 outrunner from lunacycles is a really small motor, but can legitimately do 3000+ watts. Ignore their hype about 5000 watts...pure nonsense! I really like inrunners for EV use. They don't get contamination in them as easily as an outrunner does, but they also don't breath as well either. An inrunner can be mounted by it's can or be touching stuff and it's not a problem. An outrunner needs clearance all around it so its bell doesn't rub on stuff. Inrunners tend to have excellent shaft to armature contact for good torque application. Most outrunners have very poor power transfer from the bell to the shaft via a couple of tiny set screws that shear off easily. I hesitate to suggest ever using the shaft on an outrunner for running much more than a fan. Use the bell directly and then support the end of the shaft sticking out of the top of the bell with a bearing. Outrunners are not typically designed for lateral torsional forces off the bell. IE: inrunners solve all the problems except ventilation that outrunners have in EV use.

Check out this picture, this is my big block motor...an inrunner. Occasionally the back shocks compress sufficiently to allow the motor and frame to smack together. That white line on the motor is from those impacts. An outrunner would self destruct the first time this happened to the bell. Not true with an inrunner...no real harm done.

Rewinding motors...I didn't go into EV stuff to rewind motors, but then I burnt out a couple of them and one thing lead to another and...well I found myself rewinding a motor or two.

Off the shelf parts are IMHO the way to go. I try to avoid EV specific peripherals like the CA or all-in-one solutions like the Adappto because of the intrinsic cost of all that proprietary stuff. My battery packs cost a fraction of what built ones cost and so I put more $$ into more batteries rather than into some elses pocket. I looked at getting packs built to my specs from several sources. I couldn't believe how ridiculously expensive they were. I knew what the cells cost. I knew what all the other components cost and then there was the labor which doubled the cost of the pack...and I didn't learn anything about battery packs. So I just found out how to do it myself and then from day one built my own to meet my specs. My original battery packs made by the cheapest I could find was going to be $350 each. All 4 packs once built by me cost me less that $500. So 4 times $350 or $500...that was a no brainier.

Panasonic batteries are just as good as anyone elses...assuming you are comparing similarly spec'd cells. Panasonic makes good cells. I'm currently running on 100 of the 18650PF cells and 140 used laptop cells that are mostly LG and mix of whatever. Don't confuse aH with discharge rates. Typically the really high aH cells have lower discharge rates. There's physically only so much volume inside an 18650 so whatever you stick in there all has to fill the same amount of space. So to get more capacity (aH), you have to sacrifice discharge rates (C) since there's not enough room for really beefy plates that can handle more current draw and higher C rates. Also those bleeding edge cells that are the latest and greatest thing cost significantly more than last years stuff. For example, the 18650PF can be purchased for $3.20 per cell while the latest Samsung GA cell is more like $5 each. What do you get for the extra $1.80 per cell? 200-300 more milliamp hours. Ummm...I'm gonna go with the PF and just make a slightly larger pack to make up the difference in aH for much less cost and while I'm at it, my total C rate is going to be higher too.

More great info! Thanks guys.

You are making me want to go with a 60V system. I agree about getting more controller than I currently need so as to not have as many old parts laying around over time. I too can see myself getting dissatisfied with a marginal system in a short time.

The deck is ABS and it’s not sealed. I am a decent wood worker so I’m going to make a nice deck out of maple and put some anti-skid strips on it for the same reasons you mentioned. Sealing it is a great idea.

The controller is still being mounted on the plate in the battery box, but they are not double-side taped anymore and are bolted directly to the plate. There is some ventilation but I was planning on mounting the new controller (if it will fit) to this plate and set up forced ventilation fan and vents for cooling. I am reluctant to remove the plate because it seems to provide support for the steering column. I also want to keep the battery box “clean”. I have been thinking about fans and filtered outside air intake and exhaust for the whole battery box.

I could run the 48V/1600W BOMA but I had intended to replace the motor with a higher quality one. I believe there are a lot of good options out there and I’d like to move to those with the other upgrades. I’m willing to compromise on speed to get range so the motor doesn’t have to be a monster.

Drive system upgrade: all 219 parts, no brainer.

About home building: I know that the cost is higher, but I'd really like to go with off-the-shelf parts as much as possible, the challenge is to mix and match a good set that will meet my needs. I don't really want to build battery packs and rewind motors, but I do want to "hot rod" the scooter and I believe I can do that with pre-made parts, although it might not be as much fun as a more home-grown system. Time will tell if I change my mind and start going more custom.

So, for now, I’d still like to confine my work to the battery box, so I propose a new plan……….
1. Controller upgrade: same Kelly as E-God, it’s proven and will more than meet my needs; that does have value to me.
2. Battery upgrade: I believe I can have it built to my specs but I’ll have to find out, there is also a ready-made pack available that is 60V/40A, 20Ah, 13S9P, 18650 (probably Panasonic) NCA. I don’t have as much confidence in this battery as the other but I’m just looking at options for now.
3. Motor upgrade: I’d like to stay with the 48V Golden Motor and send it 60V vs. 50V. I looked at the LightningRods motor, but they offer so little in the way of product information. I may have to ask them direct questions. E-God’s experience with it does help and I consider it a good option.

I’m curious to see what will come from my custom battery idea and I’ll post that when I get it.

Thanks for the help to all who offer it.

 

[E-ScooterDude]

Thanks EG,

I'm now planning on DIY 20S2P packs. I'm also looking for good 20S BMS and chargers.

Would you please tell me what you like for your 20S setups?

Thanks again,

 

[E-ScooterDude]

EG: I see that you answered my question on my new thread, thanks

 

[ElectricGod]

I recently purchased a couple of RC battery monitors. I had an issue with my old LIPO packs where I had a bad cell in one of them that would not hold a charge. I didn't know I had a problem for a month plus until I opened up the battery bay to do a random check since I noticed a drop off in my overall range. That's when I saw the dead cell. My BMS was still balancing the rest of the cells and now that the bad cell is no longer there, is back to working normally. I couldn't have saved the dyeing cell, but I could have known about it if there was some kind of notification about it.

Anyway, the Matek monitor is very small and has a really loud piezo alarm on it when a cell gets low. People are fairly familiar with the Celllog 8 products. This monitor is good for 6S, but is about 75% the size of a Celllog. The only thing I don't like about this monitor is the limited LCD. It can only display one thing at a time.

http://www.ebay.com/itm/Matek-6S-Lipo-Wattage-Checker-LCD-Display-Alarm-/331501308518?hash=item4d2f048a66:g:LzoAAOSwPhdU~m~h

I've just purchased a FRsky FLVSS. It's even smaller...probably 1/3 the size of a celllog and abot 3/16" thick. It is good for 6S and has an OLED that displays all 6 cells at the same time. It has no built in buzzer, but there's a connector on it for adding an external one. FRsky was going for uber compact size and using it with a telemetry transmitter so they left off the buzzer. This is probably the best and most comapct battery monitor I have found yet and they cost less than $20. I'll be buying more of these.

http://www.ebay.com/itm/NEW-FrSky-FLVSS-SMART-PORT-Lipo-Voltage-Sensor-and-Display-for-2-Way-Telemetry-/331179905010?hash=item4d1bdc4ff2:g:ussAAOSwcLxYCnf~

 

[Ianhill]

This is what is worrying me about going to BMS, I check my cell values every charge at the moment but with a BMS its all blind unless I put a watthour display on the charger output like I have on my scooter now, I can use it to count the capacity going back in and run the shunt/ relay in line with the battery when on charge, so if the voltage or current go out of range specified or reverse etc the relay will trigger and save the battery or if the end watthour exceeds it triggers off or if it does not match and falls alot short of what my scooter says I've consumed then I have some figures to work with to raise cause for concern.

http://picclick.de/120V-0-30A-DC-Wireless-Voltmeter-Ammeter-Power-222199445007.html

I would power the shunt and display with a 230vac isolated to 12vdc 2amp supply and use a rocker switch if not present on the charger to turn all off and on.

I'd like to have the BMS you posted with the screen it does make sence for piece of mind to see all cells are equal.

 

[ElectricGod]

This is what is worrying me about going to BMS, I check my cell values every charge at the moment but with a BMS its all blind unless I put a watthour display on the charger output like I have on my scooter now, I can use it to count the capacity going back in and run the shunt/ relay in line with the battery when on charge, so if the voltage or current go out of range specified or reverse etc the relay will trigger and save the battery or if the end watthour exceeds it triggers off or if it does not match and falls alot short of what my scooter says I've consumed then I have some figures to work with to raise cause for concern.

http://picclick.de/120V-0-30A-DC-Wireless-Voltmeter-Ammeter-Power-222199445007.html

I would power the shunt and display with a 230vac isolated to 12vdc 2amp supply and use a rocker switch if not present on the charger to turn all off and on.

I'd like to have the BMS you posted with the screen it does make sence for piece of mind to see all cells are equal.

I think that Chargery Power BMS has the LCD mounted on the BMS. You want the BMS close to the battery pack if for no other reason than there are so many wires. If the LCD can't be remote from the BMS, then it's not a very useful tool if you can't look at it easily. The AyaaTech 20S 80 amp BMS I bought a while ago, communicated via rs232 to it's LCD and also took a bluetooth module. RF interference on a scooter is pretty significant so a lot of things don't work well if they are wireless. I have purchased several wireless bike speedos for my EVs over the past year and none of them have worked reliably when I was on the throttle, but worked fine when coasting. Anyway, I don't know if bluetooth would suffer interference issues or not since it's 2.4ghz. The AyaaTech BMS communicating over rs232 to its LCD would allow handlebar mounted status via 4 wires while keeping the BMS on the battery pack. It seemed like a great BMS, but the implementation was very poor.

So back to battery monitoring devices like the FRsky module...
They have a standard 3 pin sbus interface on them. RC telemetry transmitters are pretty common and cheap now days. 4 of these FRsky battery monitors plugged into a single telemetry Tx would take care of 24S and the whole package would be physically very small. I have a Taranis RC transmitter and it can receive telemetry and display it on its LCD. I wonder if there is a receiver device that is just for displaying/recording telemetry data. If it was fairly small so you could mount it between your handlebars, then that could make for a very nice battery status display that showed individual cell status. It could be extended to whatever number of battery monitors you could connect to telemetry transmitters. I'm thinking a couple of solutions could be done for cheap. I don't need to see cell status every minute I'm riding, just on a random basis. I need to see current pack voltage pretty much all the time, but that's easily achieved via my watt meter. Same for amps and Ah. Getting a watt meter than can handle current in both directions so it can measure charging as well as discharging is super easy to attain so that's not a problem. My existing watt meter can do all of that. Maybe a window in the deck that opens up my site to the LCD on BMS or in the case of the battery monitors...to their screens would be enough. That keeps all wiring short and in the battery bay. A small piece of plywood or fiberglass board or aluminum to mount the monitors to would do the trick. The balance connectors on the battery pack would need to be split so they could go to the BMS and to the monitors, but that's just a lot of soldering and heat shrink and JST connectors. I've done this kind of thing every time I use a single BMS to manage multiple battery packs...no big deal. Then mount the monitoring board to the underside of the deck where the window is and you would have real time, easily seen battery status. The FRsky monitors are really small...like 1.5"x.75"x.3" so for 4 of them that would still be a really small window in the deck. Just put the windo some place where you won't normally stand and it should be OK or add a small sheet metal cover over it to prevent scratching. IE: Lift the lid and see cell status in a couple of seconds.

 

[Ianhill]

The gauge I use is either Bluetooth mode with power to the display and shunt, or connect display with a usb from shunt and then 12v to shunt only for power, if the BMS could use a similar princable just have a data line with power and gnd from bms to a display it would have minimal wiring and still highly accurate and reliable readings.

Not sure on interference but I can try out a test with my Bluetooth speaker, I'll put it on the motor and controller and play a song while revving scooter up see if I get any breaking up.

 

[ElectricGod]

The gauge I use is either Bluetooth mode with power to the display and shunt, or connect display with a usb from shunt and then 12v to shunt only for power, if the BMS could use a similar princable just have a data line with power and gnd from bms to a display it would have minimal wiring and still highly accurate and reliable readings.

Not sure on interference but I can try out a test with my Bluetooth speaker, I'll put it on the motor and controller and play a song while revving scooter up see if I get any breaking up.

I have a wireless watt meter too, but it's huge...probably the same unit you have. It can communicate via bluetooth or USB. There's the shunt and then a box in the battery bay and then the display on the handlebars. When I pulled it out of the package and saw how much space it would take up, I said ugg. I still tried it out on my bench, but it's just collecting dust in a box right now.

 

[Ianhill]

Tall they are its like they have mashed it together as an after thought but I've got plenty of space in my wagon and the charger will be a one piece unit I've got plenty of space to fit the shunt in a emc-1000 charger, I'll be able to charge at 10 amp at 84v for a 1 hour turn around on my 20s 10ah pack with the 80amp 20s bms that has a 10 amp charging limit with a Chinese level of safety.

 

[ElectricGod]

Tall they are its like they have mashed it together as an after thought but I've got plenty of space in my wagon and the charger will be a one piece unit I've got plenty of space to fit the shunt in a emc-1000 charger, I'll be able to charge at 10 amp at 84v for a 1 hour turn around on my 20s 10ah pack with the 80amp 20s bms that has a 10 amp charging limit with a Chinese level of safety.

Did you get one of these? I like them considering they are a basic BMS. I just wish they had on alarm on them to let you know a cell was going tits up.

Is your power supply adjustable? These are LION BMS. I know...they say LION/LIPO, but they really are LION or 4.1 volts per cell. Give your LIPOs a 15% longer life by not charging them to 4.2 volts. Turn down your charger to 82 volts. The slight loss in range won't be noticeable, but the lack of additional spending for new batteries definitely will be noticed. And LIPOs already have ridiculously short lives compared to LION.

This is my 3 home built 20S 24000mah LIPO packs. At some point I need to take them apart and replace the 3 dead cells...one per pack. I have spare cells so it's not like I don't have everything I need to fix the packs...just no motivation to get it done. LOL...I've moved on to the Currie scooter and here sits $400 worth of LIPOS waiting for me to tear the packs apart to get at the dead cells.

 

[ElectricGod]

Somebody earlier on in this thread was talking about shunts. I ordered some compact shunts and they arrived finally. Anyway, this picture should give a good idea what a compact shunt is like. The smallest ones are 200 amps and mid sized one is 300 amps. THe really big one is 100 amps. Basicly shunts come in all sizes and size doesn't really define amperage.