LFP reverse polarity.

[Skyler]

I am having second thoughts about a second identical front hub. Not only is the wiring for single display and throttle for two hub motors problematic, suspension forks are not suitable for a 1,500 watt motor even if I start off with pedal and assist level 1.

The bike as is with the rear hub is very smooth and easy to control from 0 to > 30 mph with 5 assist levels. The only reason for a second motor is steep hills and maintaining > 30 mph for an extended period of time.

One solution that most ebike builders would do is simply order a 45 amp controller 18 mosfet controller to replace the wimpy 30 amp that probably has 12 or less mosfets. However anyone who knows me will tell you I do not always choose the simple and obvious way.

A front fork chain drive 1,000 watts or greater and 30 amp brush controller geared for about 32 mph could give a little boost up hills and share the load and heat generated at 30 mph cruising for an extended period of time. Also it will be as simple as switching on a 40 amp DC breaker and engaging a left thumb throttle.

The hard part will be the welding but the picture below shows how it has already been done. If I have to pay someone who can weld then the rest will be fairly straightforward. I still can not seem to post youtube links here. I did figure out how to post pictures though and provided the name of the you tube video and channel.

A 10 tooth 8mm sprocket and 72T wheel gives 32 mph gearing for the chain drive.

Chain Drive Front Wheel Ebike​

Dorky Thorpy

Hope to hear from some of you on this.

Looking at specifications I may need a smaller freewheel like a 14T for around 30 mph gearing as 600 rpm is zero load and 500 rpm recommended load. What I really do not understand though is the torque specs.

For example the 1,500 watt rear hub motor has Motor Torque: 74.5 N.m

The 1,000W brush chain 19.1 N.m

I do know that gearing for a chain drive motor will change that number but do not know the formula for that.

With a 14T freewheel the 1,000W chain should do.



That is actually better than 32 mph torque wise and hills. Top speed is not important in this build. It is about hill climbing ability and maintaining 28 to 30 mph cruising for an extended period of time without overheating either motor or controller. Since Lishen LTO batteries will be used we can rule the batteries out as a weak link as they are good for 400 amps continuous.

Welding would be more logical however my welder is not here as it is somewhere else and I have no idea how to weld. Also if I manage to pull this off then anyone who reads this can copy it and mount a front chain to about any front fork. Building materials have about doubled in the last 10 years or so. I happen to have steel bed frame lying around in the basement. I will need at least 1/4" bolts grade 8. It is work in progress.

Skyler.

 

[Skyler]

That is about all I can do until I actually get the motor delivered. I will not be able to order it until next month when I get $$$$$. I can get some heavy duty 1/4" drill bits and #8 grade bolts. Once I get the motor then will know where to drill the holes.

The thing I really like is the chain will be short so easy to line the sprockets up. Way better than having the motor higher up on the forks making working front brakes close to impossible.

I will be able to remain busy however as have tons of battery building to do. The Lishen LTOs and the 68 cells from Battery Clearing house that came today.

I will be building a 6S - 8P pack and then a 4S - 3P for 12V lighting. Two of those as my friend wants one for his gas bike. I am still waiting on two 6S - LTO active balancers. I have 5 amp fuses for all the LTOs but need 3 amp fuses for all the new 26650 lfp cells. The 6S 8P will need a fuse to each balance wire and will externally balance.

Only the LTOs will have active balancers with 5 amp fuses right after each connection to the cells. However only using them during the charge cycle like I do with my external balancers when charging lfp. I will be able to test voltage on each LTO with my multi meter prior to and after balancing. This way I will never have another fire or reverse polarity issue.

It has worked flawlessly for about 10 run and charge cycles with four of my lfp packs and not needed any balancing for about 8 cycles now. All cells are around 78 to 85% when charging at 43.6V - 13S. 43.6V / 13 = 3.353 charging volts. That is at 10 amps.
For my LTOs which were brand new not < 80% like my lfp I should not have those problems and 54.6V / 20 = 2.73V which is < 2.8V. The maximum recommended charging voltage. so no worries there.

I really like the EMP case the 48 - A123 cells are in. I wish I could use it but would need to rewire it. I could have bought a 450 watt motor cheap today but really do not have any more $$$ this month.

Yo can see the last picture of my running 36V 750W gear reduction motor. It sports a Bafang in the front and single throttle. It runs spectacular. I am very happy they came out with a 1,000W version < $90. It will not be my first or last gear reduction motor. In fact if I pull it off I will be building and selling several each month to finance further and more elaborate builds , especially when I start building a lot of lfp packs.

The beautiful part of a low fork mounted motor is I can by brand new bikes from WallMart or a bike shop and simply install the motor and a rear rack for the battery and then sell it for a $100 to $200 profit.. It can be street legal and will have perfect running gears and brakes before I motorize it for < 25 mph. Once I get welding I might to be able to pull off a front 3,000 watt chain. Of course there will be one behind the seat as well for my racing ambitions. LOL

The plan for the LTOs is two 6S and one 8S pack. The cells will net be all taped up as want to test each cell easily To make that happen I need custom wood battery boxes mounted to each bike so I can simply slide them in and lock the door. I will need hinges and looking for a tight snug fit for each. I will provide pictures right here when progress is made.

Note the picture of the full suspension below. I like how you click on it and it gets really big and good close up. I am getting a new seat and the top wood rack will be much smaller for the 8P and lower bar will have 6S for each side. . Add the extra weight of the low mounted motor and low center of gravity. This beast will handle like a champ.

Probably leave the hub on level 3 and only kick in the front after about 20 mph. Gearing with the 16T sprocket on there now will be > 26 mph probably 27 with the 50V LTO.
I might leave it on there for now. Better up hills and 26+ mph is a decent cruising speed for long stretches , especially on hotter days.
Looking forwards to another great build.


Skyler.

 

[goatman]

what the heck is a Pirate doing messing around with e-bikes for

 

[Skyler]

what the heck is a Pirate doing messing around with e-bikes for

Because I have not figured out how to build an electric boat just yet. LOL.

Took a ride with the 20" e bike with the 36V - 1,000W brush chain drive a few hours ago. I have not tested for top speed with my speedometer app. since running it at 13S - lfp - 43V.

I went down the same stretch of road that I hit 32.5 mph with my 1,800W brushless motor and 38 amp 1,500W controller several months ago. It seemed to me that I was going almost as fast as the brushless motor.

The distance is .7 miles. There is a slight decline traveling the direction that the chain drives went. When I tested the new 1,500 watt kit I was going the other way which was a slight incline and hit 54 kilometers per hour which is 33.5 mph. The 1,500 watt hub motor was running 56V - 17S - lfp. The 1,800W brushless motor 50V - 20S - LTO back then.

My point is that little 20" chain drive is very fast for a 1,000 watt brush motor, especially when It is hooked up to an 800 watt brush controller. When I ordered the motor it was rated for 35 amps and ordered a 35 amp 36V brush controller but had throttle issues. It did not work until over 1/2 throttle and did not seem to be getting full power. The vender sent a second controller for free but made no difference.

Those 36V controllers actually will work at 56V though. I just do not know what the throttle issue is about. I simply hooked up a 800 watt controller and called it a day. I will test for top speed but my guess would be 28 amps for the 800 watt controller so 28 * 43V = 1,204 watts. On flat it should do about 26 to 28 mph. A slight incline probably only 23 to 24 mph but a slight decline could hit 30+ mph.



Thing I get a kick out of is how satisfied I am with that little e bike. I hardly ever ride my other e bikes. If I cold figure out my throttle issues I could only imagine how dual 36V - 35 amp motors would run on a back reinforced rack. All I need to do is solve the big mystery on the throttle issues with those 35 amp brush controllers.

Gearing could be as high as 37 mph and still climb hills as 70 amps * 43V = 3,010 watts. Basically two 35 amp 1,000 watt chain drives could beat my 3,000 watt brushless motor. I have a heavy duty 20" old school BMX Diamondback Viper. Right next to it is a vintage 20" BMX Haro. LOL. I am thinking the Diamondback for the dual brush and the Haro for the 3 kilowatt brushless motor.

It is why I am not looking for a 45 amp 60V controller for the 1,500 watt hub and am installing a 1,000 watt gear reduction on the front fork. It will hit 35 at 56V and also fly up steep hills. It is also why I am satisfied with my little 20" e bike with the single 36V motor. No need for an upgrade there. If I need to climb steep hills someday I will have other e bikes to accomplish that.

I did extensive research on single throttle and dual throttle and some suggest dual is better for turning. Let off the front going in the turn and engage coming out. My solution is to slow the hell down when turning. I only go fast when I know there is little traffic and know the stretch of road very well. I will need a full helmet and crash suite. I don't know if I have the cojones to go over 40 mph with the 3 kilowatt motor.

Skyler.

 

[fechter]

Try measuring the throttle signal voltage going to the controller. A normal hall throttle should go from around 1v to 4v.
It may also be possible the controller was made for a resistor throttle, but this is rare.

Another test is to disconnect the throttle and try placing a jumper from the 5v line to the throttle signal line and see if you get full speed (wheel off ground!).

 

[amberwolf]

It may also be possible the controller was made for a resistor throttle, but this is rare.

It's not uncommon for *brushed* controllers to use potentiometer (resistive) throttles, but ones that use hall throttles are a lot more common than they used to be.

To be sure of what's going on, we'd have to see what the OP is actually using, preferably with links to the sale pages for each part, and clearly readable pics of all labelling on the parts and documentation that came with them, if any.

 

[Skyler]

Item specifics​

Condition
New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is ... Read moreabout the condition
Model
DC 35A
Controller type (if included)
DC Brush
Controller with Reverse
N
Type
DC Brush Controller
Wattage
1000
Voltage
36
MPN
XK-8D1-33
Brand
XYD
Suitable For
Electric Go Kart
UPC
3183884112216

Variable Speed
MOTOR CONTROLLER 36 Volts
Max Output: 1260W
Use for 1000W Watt 36 Volt Motors

Dimension: aprox 5" x 3" x 2"
Weight: 1.1 Lb
Brand: XYD
Model: XK-8D1-33
Max Power: 1150W


This speed controller features functions and connection terminals for:
Required:
- Battery: Connect to 36 volts (will not work with less than 36V)
- Motor: Use with Brushed Motor
- Throttle (use with compatible variable speed controller). Always match red and black cables.
- Power Lock / on-off switch (use with a simple switch to turn on the controller)

Optional functions:
- 2 Brake ports (will shut off motor) - Use with micro switch fitter to brake handle or pedal
- Battery Voltage Display - Use with voltage indicator
- Headlight
- Charger - Verify polarity before connecting

Yea.

1,260W or 1,150W. Which is it ?

Obviously the seller did not take the time to read over the ad before posting it. Things like just do not get by me at this stage in my e bike building. LOL.

I do have a power meter which can read amps. watts and voltage. It also displays peak vales. I have a simple one as well as one with a shunt which requires many wires so never hooked it up.

I just need to hook the simple one up and a digital camera to record all data onboard. Also my GPS speedometer and I also have a sunglass camera I think is HD quality.

I just need some sort of dash board which I can move from one e bike to the next as have 6 e bikes running now and looking at 3 or 4 more in the next year or so.

It might be a a month or two before ordering two more 36V motors and not unhooking the 800 watt controller I am currently running as if it is not broke do not fix it is one motto I entertain almost daily. That 20" set up is test proven to be very reliable and decent performance.

I am now dealing with 24 LTOs and 68 lfp cells as well as building battery boxes. Then I will be ordering that 1,000 watt gear reduction motor for the front fork on the full suspension.

After that I will order two 36V brush motors and then deal with those controllers. I am eager to embrace that as well as a dual motor set up on the back of the 20" Diamondback Viper. The 3 kilowatt brushless motor will just have to wait until after that.

In fact the Diamondback as well as the Haro will be race bikes. No limit to my insanity for both. If I can squeeze a 1,000W gear reduction motor on the front of the Diamondback then three 1,000 watt motors at 56V will be racing a 3,000 watt with a 1,000 watt motor on the front of that. Both bikes geared for around 56 mph. LOL.

1,000W / 36V = 27.7W * 56V = 1,555W * 2 = 3,111W + 1,000W / 48V = 20.8W * 56V = 1,166W = 4,277 watts. - Diamondback viper.

3,000 watts @ 60V + 1,000W / 48V = 20.83 * 60 = 1,250W = 4,250 watts. - vintage Haro.

The 3,000 watt motor will get all 24 - LTOs for 60V and the Diamondback 17S - lfp - 56V. The problem will be finding a 60V brush controller for the front motor on the Haro so will probably go with an 1,800 watt brushless motor on the front so will be no contest unless I can find a way to run four brush motors on the Diamondback.

1800 / 48 = 2,225 + 3,000 = 5,225W - 63 mph gearing.

So basically if I cant beat the mini bike with the Diamondback I will break out the Haro. LOL.

All I know is it will be some scary fun when it happens. LOL. However it will not end there.

Once I start building and selling e bikes I will be saving up my $$$$$ for a 10,000 watt QS motor and a downhill full suspension bike. Probably a 3 kilowatt front fork motor running at 72V for 3,600 watts + 10,000 for 13,600 watts and 76 mph gearing.

I also have a belt driven electric motorcycle motor rated at 45 kilowatts with an 80V - 400 amp Sevcon controller. I have no idea how to build that but know I need at least a 250 cc dirt bike frame to start. Also 12 more Lishen LTOs.

Thank you guys very much for taking an interest in my work and posting,

Skyler.

 

[Skyler]

I have been working on the LTO batteries and designing a rack to hold them. I have also been thinking about the intelligent controller that came with the 1,500 watt kit. Even though I am not happy that it is probably only 30 amps as it has a 35 amp fuse I absolutely love the five power assist settings which work without any pedal so I can take off nice and smooth and increase power as needed.

The picture below shows an 800 watt hub motor I have had for about 8 years now I think. It got rusty and the spokes started falling out. I just need to replace all the spokes. I had two controllers for it. One 800 watt and a 1,000 watt. They are old style with a power switch on each one. They are the same size and no information on either.

One I threw out and may throw out the other as well as both have 4 wire throttle hook ups and have had a lot of trouble with each. I was really hoping to find a 40 or 45 amp controller for the 1,500 watt hub motor and use the 35 amp the kit came with for the 800 watt motor when I get the spokes replaced. The sensor wires are in good shape.

My question is where do I find intelligent controllers with the five power levels on the display. That 20" hub motor has a lot of torque and is a front motor which I ran on the back of a 20" e bike awhile ago as was too squirrely for the front. However with an intelligent controller with that display I could control that little beast nicely.

My other question is do they make sensor less intelligent controllers with a display and five assist levels. Even though the sensor wires are good on the 20" hub motor I would like a sensor less option in case that changes.

If anyone knows please post a link.

Thanks.

Skyler.

 

[Skyler]

I like the five power settings on the intelligent controller that came with the 1,500 watt kit.. I was hoping to upgrade but need the same five power settings.

Then I cold use that intelligent controller for my old 800 watt hub motor. I had two old style black controllers that looked the exact same. One was 800 the other 1,000. Neither seemed to work and ordered a new 4 wire throttle and did not work. I threw one out and looking to cut off the plugs on the other and throw it out as well.

I hate 4 or more wire throttles. The 20" hub motor has a lot of torque and really needs an intelligent controller. I am wondering if I could get a dual mode , sensor / sensorless. The sensor wires are functional and intact now but like to still be able to run it if that changes.

I wish I could find the specifications on the motor and controller. Technical info like Stator size , magnets ect. For the controller how many Mosfets and amps. All I got to go by is a 35 amp fuse.

I took a picture of the controller. 48V was the only thing on it I could read.as all Chinese and no manual with the kit. I sent the picture to my own email and taking awhile to show up. I got these though.

 

[calab]

6 e bikes running now and looking at 3 or 4 more in the next year or so.

Wow, that is amazing. I usually have one bicycle as a spare whether it be in pcs or ready to ride/convert to ebike with a spare motor/cont. Doesnt take long to convert once you've done it for awhile.
Being able to ride different setups with different power and testing on various terrain then you get to realize very quickly what you like and dont like.

Do you have like 2 or 3 homes with an ebike or two at each home?
I bet you its more like you built them for family hence so many ebikes in your garage?

 

[Skyler]

I can not read Chinese. I wonder if there is an app. that could recognize an image and convert to English.

I did try and look up the manufacture but could not get any information about my kit. Looking at dozens of controllers online and I see nothing like the one in the kit. I am looking for the plug the LCD display connects to and the name of the display as I like the 5 power levels.

I want to try putting that 800 watt motor on the front of one of my 20" e bikes and see how it runs with an intelligent controller. I was also hoping to find a sensorless intelligent controller that has a three wire thumb throttle instead of the twist grip.

Any information on this will be greatly appreciated.

Skyler.

 

[nicobie]

If I can't read that blurry pic, for sure a translator app won't be able to either

 

[Skyler]

Trying out my camera settings. Maybe it was too close. I took another picture. It seems to be working ok at a distance. Not sure.



Been working on the LTO battery rack. I will take more pictures after sanding and painting.
Had to make space for the front rack for turning so screwed in a short board to the bottom.

Also I need glasses. I can read it and see it is a 30 amp controller like I thought. Makes sense with a 35 amp fuse.

Looking at the wiring coming from the motor. I would never run it at 40 amps without upgrading the wiring. I really do not want to do that. With the front motor it should not over heat up hills or long distance around 26 to 28 mph.

I need to upgrade my phone as camera sucks.

Skyler.

 

[Skyler]

I have been working on the LTO batteries and the battery rack and boxes.

One thing anyone who works on e bikes must know is how to solder. I use a 60 watt iron with a temperature control knob for small jobs and a 100 watt constant temperature with a larger tip for bigger jobs like 10 or 12 gauge wire and 26650 cells.

One of my 6S Lipo chargers broke off as when I moved down from Alaska the banana plug was plugged in and broke off the piece inside. It had to be done right the first time as if any solder got on the board it would short out the unit. It now works perfect so have two 6S Lipo chargers and both will charge lfp.

They will also charge LTO but not balance as

4S LiPo = 16.8V / 6 = 2.8V It is why I ordered a 6S active LTO balancer but will never run it when discharging. Only before and after charging. That plus the 5 amp fuses to each balance wire will guarantee nothing will ignite.

I also use an electric face mask I bought back when COVID happened so I do not inhale solder fumes. It has two speed settings and filter. I am charging it now.

I have much more soldering and painting to finish the LTO packs. I have decided on the two 6S boxes and a 8S for 50V and a 4S I can put in series with the two 6S for 40V.

Skyler.

 

[Skyler]

I got more Max strength black duck and electric tape and got store credit towards 15 more 5 amp fuses as got two 10 amp packs of 5 by mistake. I now have everything needed to finish the LTOs.

I was searching youtube and nobody tested the cheapest 1,500 watt kit on e bay yet. I cold do one I guess. I was hoping to see it tested already to know what to expect. The phase wires look a little on the thin side. It might be 35 mph capable but I prefer not to draw 30 amps for more than a few seconds.

The wires are silicone but could be way better by rewiring the three phase and eliminating the sensors as can go with thicker gauge phase. I have heard good and bad about greentime controllers but had a good sensorless 38 amp 1,000 watt controller but got rid of it a few months back. I wish I didn't. It did not have the 5 power levels though like the stock 30 amp controller in the kit.

I just hope I can pull off the front chain as even though the kit hit 33.5 mph and can most likely do 35 mph I would hate to be broke down with melted wires or a burned out controller. Both conditions from pushing 30 amps continuous > 60 seconds. Maybe even 30 seconds. The wiring looks like a 750 or 800 watt kit.

A 28 or 30 amp 1,000 watt brush motor in the front will make a huge difference sharing the load. I can get power meter and up to 20 amps use just the hub. 25 amps < 15 seconds. If each motor draws about 20 amps then 40 amps * 50V = 2,000 watts. Plenty of power for 30 mph cruising. A 14 tooth freewheel will give me about 31 mph gearing for the front chain.

With one power meter 30 mph can happen with just the rear hub. The power meter recorded by onboard camera. Then I do the same road with just the front motor. Then do both. Include a decent hill, if possible after the flat.

Grin technologies has a computer to figure all the variables but gave me a headache looking at it. Maybe somebody on here can crunch the data. I bet some interesting results. Dual motor ebikes are interesting as increases both torque and horsepower over the single motor. Also 200% better heat dissipation in the system. Another bonus is 200% more traction. Double strain on battery though but defiantly does not apply to LTO or lfp. Maybe a cheap 30 Ah fake Chinese lion pack for < $200 would hook up and become the next Hindenburg.

NY state Mayer was on the big news conference about e bike safety and a lot of eyebrows raised over liCo. Lithium ion. , LiPo. But mainly Lion. I was wishing I was there as would have had a sign with two three letter words.

LFP LTO

Skyler.

6/28/23

Looks like the 5 in 1 meter will charge LTO on the LIFE setting. The LiPo charger is set at 4S LiPo - 4.2 * 4 = 16.8V / 6 = 2.8V.

The blade fuse takes way less space than the inline fuse. It is easy to solder to so might be using them instead. I used 18 gage wire for the balance wires soldered to the 5 amp fuses very close to the cells.

I really do not like the 22 or 24 gauge wires connected to the balance plugs. It is why I cut really thin strips of electric tape and then wrap all the balance wires together. I also wrap a piece around the balance plug to make sure no wires come off.

By not using a BMS or active balancer there is no way it can short the board and start a fire. I can still use the 6S active balancer but will use exactly like I do with the external balancers. I might use while charging but never when discharging as that is when I had the reverse polarity fire.

I just checked and am very happy that the 5 in 1 balancer is doing the job. I applied 3 coats of paint but just for the layers of protection. To save $ I paid $10 for a quart. instead of $15 but was white and had to be mixed to make flat black. It did not work. I got a weird shade of dark grey. I got a spray can flat black for final 2 coats. First I am getting a new belt sander as my old one broke.

I also need a Dremel tool to counter sink the screws. Then putty , another coat of weird grey , sanding and then two coats flat black. That will need to happen for four LTO boxes and each bike that will run LTO will need it's own rack for the LTOs.

I still have a lot of work ahead of me.

Skyler.

 

[Skyler]

The 10 gage wire I got at Home Depot I think and for 220V heavy duty appliance. 30 amps continuous. 50 amps < 60 seconds. 8,000 watts I think. Is what I used for the series connecters for the ring terminals for the LTOs.

It sucks though for power connecters as not flexible and difficult to solder to. Not sure how it compares to silicone but the insulation on it is serious shit. Super heavy duty.

For up to 1,000 watts I use 16 gauge house extension wire both so 16 gauge * 2.

For 1,500 to 2,000 watts. ???

Walmart has 12 gauge so thinking four strands together for 60 amps continuous.

Much easier to bend and solder. That appliance wire is brittle and breaks.

Home

Cerrowire is a leading copper wire supplier offering MC cables, aluminum wire, and building cables for reliable electrical solutions.

www.cerrowire.com

Wire Gauge Size	60°C (140°F) NM-B, UF-B	75°C (167°F) THW, THWN, SE, USE, XHHW	90°C (194°F) THWN-2, THHN, XHHW-2, USE-2	75°C (167°F) THW, THWN, SE, USE, XHHW	90°C (194°F) XHHW-2, THHN, THWN-2
14	15	20	25	---	---
12	20	25	30	20	25
10	30	35	40	30	35

Skyler.

 

[fechter]

On a bike, you can use much smaller wire than the official amp ratings for line power use. I've used 10ga. for 60A and it barely gets warm.

 

[Skyler]

On a bike, you can use much smaller wire than the official amp ratings for line power use. I've used 10ga. for 60A and it barely gets warm.

That is what I thought. I have run 26 to 30 amp controllers off 16 gauge home extension cord but use both so 16 gauge * 2 is like 12 gauge. For those 18 amp controllers for Bafang motors I usually just go with the single strand especially with dual motors as each motor usually only draws like 10 to 15 amps as they work together to share the load.

Steep hills cold create a problem though so should check the wires and controllers plus the motors for a really big hill. Might have to get off and push a while until shit cools down. Here where I am now there is not too many steep hills.

I just finished the Giant Rome. Dual motors and controllers with single throttle. Both 18 amp 36 / 48V controllers. 26" rear Bafang and 700c 500W e bikeling motor up front. The stock 22 amp e bikeling controller died awhile back and waited about 5 weeks for a new 18 amp controller to show up. It is just like the rear controller. I bought the rear motor for $40 about three months ago. I was told it was a 500 watt motor so might have had a 22 amp controller stock. I did not get the stock controller and had an extra 18 amp.

I am also finishing up my LTO boxes. They are not perfect and wont be until I get a new belt sander but have been charging them and balancing for several days now. I will run 20S for the 1,500 watt hub motor on the full suspension.

For the Giant Roam I was going to run 43V lfp. The two 5S - 8P 26650 A123 cells in series with the 3S - 3P headway cells. I even built a front basket for the 3S - 3P Headway pack.

BUT !!!!

I do not like the front basket. I would rather NOT do it. I have that 7S - 8P LFP pack also with the 26650 A123 cells just sitting.

I have come to a point where my expertise has reached its limits. Like I said I am no greenhorn when it comes to building e bikes and batteries but I am thinking about doing something probably never done before. Not sure. I have done extensive research and do not see it. From what I have found is in solar systems LTO and lfp have been hooked up in parallel but no information at all about series.

I really want to get rid of the front basket and run two 4S - 1P - 18 Ah - LTO packs with the 7S - 8P - lfp pack in the middle. LOL.
Even if I decide to keep the front basket I will have about 2" extra leg room for pedal as can move the batteries farther up towards the front with the longer lfp pack in the center as the 4S LTO packs are shorter so will not interfere with steering. They are the perfect fit and greater performance

About 44 working volts as 2.5 * 4 = 10 so 20V LTO and 3.,3 * 7 = 23.1V so 43,1V. Around 45V fully charged.

Not looking for long range. Maybe 5 or 6 miles with the Giant. For 15 to 20 miles I will run the full suspension with 20S LTO.

I found this on a google search but think he is talking about parallel. Not sure ????

[IMG alt="Sunder"]https://endless-sphere.com/sphere/data/avatars/m/22/22098.jpg?1676495252[/IMG]

Sunder​

10 MW​

JoinedSep 6, 2011Messages3,054LocationSydney, Australia

• Apr 2, 2018

Yes, its possible. Depending on use and diffefence in cell performance, you might not even require the control circuitry you describe.

I am running a 36S LiPo woth 43S LiFePo4 for 18 months with no issues.

I have also run 8S LiFePo4 with 11S LTO for 8 months with no issues.

No control circuits for either.

eBike: Q100H on 16S with Phaserunner FOC Controller
eMotorscooter: Vectrix VX-1 Died... Electrified Ninja in Progress!
eCar: Mitsubishi Outlander PHEV... Warramty expired. Still not game!
eHouse: 6.2kw On-grid solar with battery backup coming soon!

Also running the full suspension 1,500 watt motor I was thinking about the two 6S LTOs in the custom rack I built and the two 4S - LTOs in the rear basket. 20S LTO = 50 working volts.

BUT.

12S - LTO = 30 working volts + 3.3 * 7 = 23.1V = 53.1V. Two 6S - LTO in series with a 7S - 8P 26650 lfp pack. Looking at capacity for the lfp we get 2.5 Ah * 8 = 20 Ah. However the lfp is only like 80% capacity but still 20 @ 20% = 16 Ah. Still very close in capacity and looking at < 10 miles.

Discharge wise the A123 cell boasts 50 amps * 8P = 400 amps.

18 Ah Lishen - 1P - 900 amps. LOL.

Welcome to the big boy post in ES battery technology !!!!

I am asking a serious question. Hoping for some good answers. No BMSs involved. just RAW POWER !

All balancing done during charging cycles.

I know I will need to charge LTO and lfp separately so only asking about discharging.

Can I do it. ???????

Please let me know as do not want to destroy my batteries.



Thanks.

Skyler.

 

[fechter]

There's no reason you can't run two chemistries in series, you just need to be sure you don't overdischarge either one. Some kind of voltage monitor for each one would be a good idea. A BMS would be better.

I'm interested to see what kind of voltage sag you get with the LTO cells. They're supposed to be pretty good.

 

[Skyler]

That is what I thought.

I think 50V - LTO might be = to 56V - lfp. Even though lfp can do a lot of amps there is a noticeable voltage drop compared to LTO or liCo under moderately heavy loads. 30+ amps. LTO is about like LiPo. The LiPo packs Hobby king sold. I think 30C discharge and 20 Ah. Green bricks. Low voltage drop under 30+ amp load. Obviously LTO is the winner in discharge amps and 1,000 times safer.

I don't think my budget will allow for a front motor on the full suspension. At least not this month.

My money is going into all new locks on both doors and the basement door will get a dead bolt. All my e bikes will be down there if I decide to take a trip. I want to travel. Only taking one with me. I might go back to Alaska next month when the temperature is in the 90s here in the states. If I do have any extra money left I need to invest in brake work on almost all my e bikes.

The painting is finished on both the dual suspension and Giant. I put a 80 amp fuse in one of my series connections. The power wires all have female bullets so it is not possible to plug the negative and positive together by accident and placing the fuse in the series connection just makes it idiot proof.

The Giant needs a lot of brake work. The full suspension some slight adjustments. I am looking at riding the 20" 1,800 watt brushless motor for a few days until I can get the brakes done. I should probably sell some e bikes but I get attached to them. I ride one or two awhile and may go many months not riding the others so when I fix them up and do ride them it is the feeling like a new toy.

Looking at that snotty 800 watt 20" motor for the front of either the 20" 1,800 watt brushless motor or the one with the 36V brush chain. I am thinking the brush motor at 43V could work with the front hub as not as squirrely as 56V lfp or 50V LTO.

I had enough solder to hook up the power meter which displays data for volts , amps , watts and peak values. Looking at modifying the rack on that 700c hybrid with the 750W gear and front Bafang. It is a super beast for off road and dirt. Stock was skinny tires like old 10 speed tires. I always hated them.

The skinniest tires I will even ride on would be the Giant Roam. Skinner than that forget it. I would love a fat tire e bike but the 700c hybrid will get the job done. The stock tire on the 1,500 watt hub motor was a little on the skinny side for 1,500 watts I thought. So I switched tires with the 26" Bafang on the back of the Giant as the front e bikeling motor has a skinny tire to match. It is a road bike. It would suck off road.

Even a 350 watt front hub on a 20" bike will improve off road handling and traction. If a geared hub than is like a freewheel. Zero drag. You only need it if off road or maybe on a steep hill. Likewise the 30 amp 1,500 watt hub kit don't need a heavy 1,000 watt gear chain drive in the front. That bike is too heavy as it is. A 350 watt geared hub would be absolutely perfect and very light. Extra traction and a little help up hills and about 15 pounds less weight.

I am still going to do a front chain but thinking about a different ebike. I have an old steel frame. Maybe an old izip or something. 26". Older ebike like a decade ago maybe. Batteries slid on the rear rack. I got no motor or batteries and removed the rack. I got the frame for $20 or so I think. It was a long time ago.

Thinking about a Kelly controller. I think they make the best brush controllers. 50 amps would work but 80 or 100 could do three brush motors. Two in back and one up front. All three like that brush motor on the back of that 20" bike. 1,000 watts @36V 35 amps.
50V - LTO it is a 1,500 watt motor. Three is 4,500 watts for 56 mph gearing.

Thanks for posting.

Skyler.

 

[Skyler]

here's no reason you can't run two chemistries in series, you just need to be sure you don't overdischarge either one. Some kind of voltage monitor for each one would be a good idea. A BMS would be better.

I'm interested to see what kind of voltage sag you get with the LTO cells. They're supposed to be pretty good.

I have been running the Giant Roam with the 500 watt rear hub and 500 watt e bikeling motor up front. Both sport 18 amp 350 watt controllers and a single thumb throttle.

Working voltage is 3.3 * 7 = 23.1 + 2.5 * 8 = 20 ; so 43.1V. One 7S 8P - LIFEPO4 and two 4S - 1P LTOs. I will know more when I hook up the power meter. I want to record the dats with a camera.

Skyler.

 

[Skyler]

Contemplating my next build.

Looking at 40 working volts of LTO for a 20" bike with three 36V - 35 amp brush motors.

Two will go on the back hooked to a single 44T spoke sprocket. One up front with 44T sprocket. Both will sport #40 chain.

Looking at a Kelly controller.

KDS – Mini Brushed DC Series/PM Motor Controller (12V-72V) (50A-200A)​

1. 
2. 

Share

SKU KDS48100E

Motor RMS Current, 1 minute: 100A.
•Motor RMS Current, continuous: 60A.
$89.00

Gearing will be approximately 49 mph at 3,333 rpm @ 40V LTO.

Skyler.

 

[Skyler]

I need some good advice.

I have a friend Tom. He is in his late 50s He is at least 270 ponds and owns a beach cruiser. He wants a front hub motor as I do not think a rear will fit. Also a 500 watt motor probably wont work as his weight going up a hill.

He wants a 1,200W kit. I already told him his stock forks wont work. I need to know where he can order heavy duty steel forks preferably with no lawyers lip. He is ordering the parts and my friend Dave will do the forks and brakes and I will do the motor and controller and mount the batteries. He is ordering 4 -24V lfp batteries from Battery Hookup. They are 24 amps continuous so hooking him up with 2S 2P for 48 amps.

Thanks.

Skyler.

 

[Skyler]

I talked Tom ot of the front 1,200 watt hub kit. I told him I broke several drop outs with front hub motors. Even a 350 watt Bafang a few years ago.

If his rear end is steel I might be able to spread them apart to accommodate a rear 1,000 or 1,500 watt hub kit. I am taking a magnet up there soon to find out.

I had another reverse polarity issue. This time with 4S LTO. Not sure how it happened. The other 4S LTO was at 60 to 70% and the 7S LIFEPO4 about the same. I did a diagram in paint showing how it was and how I changed it by moving the fuse.

two of the LTOs were about 0.6V and one at 1.2V and the fourth - 2.3V. That is 2.3V reverse polarity. The next day it was negative 0.6V and two days after that positive 0.3V. The LTO cell actually reversed back. I did not think such a thing was even possible.

Using the Nickle metal halide setting on the LiPo charger I got it back to + 2.3V quickly and have checked it twice in five days and no self discharge. I also charged the low cells back to normal. It took at least 3 days on the charger back in 4S charging at 3S LIFE hooked to both a 6S 1.2 amp active balancer and the 5 in 1 balancer to get all 4 cells close to 2.6V.

3.6 * 3 = 10.8V / 4 = 2.7V. I did not use the cell that reversed polarity as I had and now have 4 cells left over as ordered 24 for 60V but only built 4 boxes for 50V. Two 6S and two 4S. I finally tested them out according to the bottom illustration but only about 2 miles.

They ran great and are balanced with a lot of capacity left. My plan is to build a 6S 8P LIFEPO4 pack to run in series with the 7S 8P LIFEPO4 pack and then order two 6S LTO BMSs and an 8S LTO BMS as well as two 6S 5 amp and an 8S 5 amp active balancer.

I have learned my lesson. I really need a BMS for each LTO pack for under voltage protection. Then I can run 20S LTO exclusively and charge at 15 amps with my 54.6V LFP charger. Running small 4S packs is asking for problems. Since I run 43V a lot more often than 48 or 50V I need two separate 43 volt battery setups and one good 50V setup.

Also I did extensive research on my own and found that running fuses between series connected batteries is problematic. I removed the 80 amp blade fuse in the illustration and soldered in a 60 amp bus fuse in the negative power wire going to the controllers. The positive side is wired to a 40 amp DC breaker for the dual 350 watt 18 amp controllers.

I am now hauling all three packs down in the basement to top off the charging. The LTO pack I rebuilt was well over 2.5V at about 1/2 way or 1 mile into the trip. The other was slightly higher with two cells close to 2.6V and the 7S - 8P LPF pack was around 70% according to the 5 in 1 meter. From now on if or when I run that set up again with mixed battery chemistry I will be taking my meter with me. It is not really a practical set up as impossible to charge LFP which are 3.3V nominal and LTO at 2.5V nominal together. They have to be charged separate so looking at < 3 miles

With 13S LFP I can portable charge at 10 amps with my 43.8V 12S LFP charger and with 20S 50V LTO 54.6V @ 15 amp with my 15S LFP charger so as soon as I finish the 6S 8P LFP I will have two 43V LFP setups and will combine the two 4S LTO packs for an 8S to run in series with two 6S. The 8S will be in the middle and wired like the LFP pack in the diagram below. I took out one of the negative fuses in the two 6S LTO packs and the 8S pack will be no fuse so will be the same as the illustration below but with the 6S LTOs on either side and the 8S LTO center.

It will be next month when I get $$$ so pricing 6S and 8S BMSs as well as 5 amp active balancers. I will also wire in 10 amp fuses for all balance wires between the cells and BMSs and balancers. It will be a lot of work but well worthwhile for the long run.

I just got back from the basement. This time the mixed chemistry LFP + LTO behaved a lot different. Both 4S LTOs did not seem to discharge at all or very little. I tried charging them several times but got a FULL reading on the 6S Lipo charger in about a minute or less and each cell in both packs above 2.5V about half close to 2.6V but cell banks in the 7S 8P LFP battery around 28 or 30% ; down from about 68 to 70% starting out.

My conclusion is to not run them together much more than a couple miles as they will not charge together or discharge evenly. 3 miles is the absolute maximum if all the LTO cells are close to 2.6V and the LFP cells > 85%. Anything less will be risky to say the least. I am looking at newer 90% or above tested LFP cells that are 3 Ah in the future for a 17S 10P 170 cell pack for 25 to 30 miles.

That will take some time to save that much $$$$$. I may even order a decent spot welder for that. Not sure.

Battery Hookup

Sony US26650FT 3.2v 3000mah Lifepo4 - Tested​

Regular price$1.50Sale price
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These cells are made in Japan and come fully tested. They were recovered from unused battery modules, we removed the nickel strip, then professionally tested them on our 512 channel cabinets. Every cell is resting at nominal voltage and ready to be built into packs.
Every cell tested between 90-100%.

Skyler.

 

[Skyler]

My conclusion is to not run them together much more than a couple miles as they will not charge together or discharge evenly. 3 miles is the absolute maximum if all the LTO cells are close to 2.6V and the LFP cells > 85%. Anything less will be risky to say the least. I am looking at newer 90% or above tested LFP cells that are 3 Ah in the future for a 17S 10P 170 cell pack for 25 to 30 miles.

Well I have been running the same configuration and charging the two 4S LTO packs in parallel about 6 amps and the 7S LFP at 3 amps with the other Lipo charger and each pack gets a separate external balancer.

I have been going close to or 3 miles a day two days in a row now. No more issues. I guess I made a mistake before as the LTOs charged to almost 2.6V today. Before a little above 2.5 so getting greater capacity from the LTOs. As long as the LFP is at 85% or higher they seem to run great together. Suitable for short trips which average about 3 miles.

For longer trips 10 and 20 miles which I rarely do I will need either 13S LFP with the 43.6V 10 amp LFP charger or 20S LTO with the 15 amp 54.6V LFP charger. I can not portable recharge with a mix of the two as the cells are different voltage.

Looking at brand new 14 Ah LFP prismatic cells on ebay. $195 for 16 on sale. I wish I had the $$$$ but I do not and not sure when I will. I will need three BMSs and 5 amp active balancers for each LTO pack next month so I can combine the two 4S LTO packs into a single 8S to go in series between the two 6S LTO packs for up to 20 mile range.

Skyler.