Making my own battery pack

[DirtyGinge]

aww dude, hope you are ok soon...get some schwalbe ice spikers...ice is not to be sniffed at,,,failing that get some bomber shorts

Times have changed since we last spoke, and Im back in the ebike business due to circumstance ( and yes I had to go and buy again what I sold you lol )

im working on a stainless steel kickplate triangle battery pack bolted to the frame...heat dissipation, centre of gravity, should work a treat, and look almost as sexy as I do

The problem I had with backpacks is that my front wheel never wanted to stay on the ground on high power take off's...One M4 roundabout looking like evil knevil finished that Idea for me

Hope the family is keeping well

p.p.s got a few more 18650 cells that im not using .....if ya want them

[Andrew]

well, its good to have you back on board. 

I am not sure how long the back pack thing will be used as I too am working upon a triangular frame solution for my suspension frame      I have so far made two press moulds from PVC foamex plastic that will be bolted together to the bike frame. The container will cover of the top frame bar as well as the inner triangle allowing more room for cells. Thanks so far to the DT department in school and the diner ladies who let me use their big oven to heat the plastic sheet before ipressed it over the wood moulds I made.  that's as far as I have got at present. Next step is fitment, i.e cutting, sealing and making a side flap for access.  Big plans with lots of problems ahead of me!

[Gregor]

Good luck with that Andrew. Why not put up step by step pictures with an explanation of what you are doing.
That could be a hit. I would follow that. It might encourage others.

Gregor.

[Andrew]

as usual, it is finding the time. I am meaning to take some photos soon of both battery carrier solutions I have been working on.. i.e the plastic mould and the back pack solution.  Both are for my full suspension mtb  for off-road use only.  The commuter bike has a frame mounted bag for the controller and cells.

[Gregor]

What volts are you going to be putting out of that pack?

[Andrew]

i stick to 54v as this is enough for me. I have mpacks of lipo cells wired together, each is 54v and 3ah, I have seven in total which can be paralleled together to make upto 21ah. I use the lipo just for my full suspension bike with a PIE mk2 for off roading.  the controller and cycle analyst will be set to 35amp max, so will pull 2000 watts.   I have had a lot of help along the way from Forum member DirtyGinge and Bikemad.
I was exactly where you are now 3 years ago. I went through various hick-ups and cock-ups from Golden motor but overcame them all and have had a steep learning curve.
I now do lots of soldering, tinkering, bodging, modifying.
Build li-ion packs
Build wheels
and have built over six different bikes/kits/variations along the way.
I did not know the difference between volts and amps when I started never mind anything else related to ebikes.

[Gregor]

One question. My controller was set at 30amps continuous and 70 max. Peddle assist was at low, I don't use it anyway. RPM set at 90%, voltage36V, speed scale 100% and the regen at 50%. All I have did with the software was disable the reverse and turn the regen down to 1%. Question is, does that sound ok? I have the 48V10AH lipo battery.

Cheers

Gregor.

[Andrew]

i think you have a Lifepo4 battery a bit different to Lipo but still a very good discharging chemistry.  70 amp max sounds very high to me, but what the GM controller does and says are two different things.
If you did pull the max 70amps at 42v on full charge that would equal nearly 3000 watts. Your motor inner parts and wires would melt at that wattage . If the controller really lets out 30amps then  that is a good amount for your set up. the older controllers were very limited..  i.e 17amps max.
If you connected a watt meter you would probably find a peak of 1200w or there abouts.

[Gregor]

Sorry Andrew, My bad. It is the Lifpo4 that I have. My mistake.

The new controller that Gary Salo sent me was the upgrade.

I have sent Bikemad A.K.A. Alan the exact settings to ask his opinion.
No offence meant to you but he does seem to be a guru.

Gregor

[Gregor]

To backtrack a bit. Have you put any pictures of your bikes on here already?

Gregor.

[Andrew]

there are some piccys somewhere of old bike builds.

here are my two ridses at present.....








Two pies......




two mini motors on this one




The wife's mini motor



Another build....

[Gregor]

Nice rides. Where do you put your battery on your fully sussed bike and how do you stop your controller getting a soaking?

[Andrew]

Nice rides. Where do you put your battery on your fully sussed bike and how do you stop your controller getting a soaking?

I am experimenting at the moment with the controller placement and battery pack. I have done my best to make the controller waterproof so it can be mounted externally, which is probably a good idea due to the power going through it. 
I do have a small frame bag that the controller can go in within the frame. A battery wire comes from the controller in the bag and goes up the seat post and I connect to the batteries on a back pack with a coiled cable under the seat.  This still keeps everything back heavy, hence trying to make a PVC plastic moulded frame container.

[DirtyGinge]

well im preparing on making an aluminium triangle for the bike frame, housing the lipo, and potentially the controller innards as well. That way I can heat sink the fets direct to the outer casing... got a wooden one built at the mo, and the low centre of gravity really helps the stability......

As for the pie settings, I found that 20 amps with peak of 60 was plenty for commuting, but that wasn't with a GM controller..

Also plan to hard wire the controller soon, getting rid of all the finicky plastic connections and go for direct solder, just cant decide which controller to stick on it, sensorless or sensored

[Andrew]

You know sensorless makes more sense....     if that makes sense!