Building an EV motorcycle. Batteries: Need opinions.

[TurnNBurn]

Originally Posted by oil pan 4

Yeah I got about 0.6KwH worth for about $250 shipped.

Where did you order them from?

[oil pan 4]

Originally Posted by TurnNBurn

Where did you order them from?

Ebay seller in china.
I tried to contact A123 battery systems in the US but they are stupid, useless and bankrupt now.
There is pretty much only one place for a battery maker to go when they build batteries, throw most of them away and refuse to sell them to any one.

[TurnNBurn]

Originally Posted by oil pan 4

Ebay seller in china.

Darn. I'm sure there's a website that sells them. I don't have an eBay account. Lately things on eBay are more expensive than Amazon.

[oil pan 4]

The website is useless.
That website was A123 battery systems customer inquery web page.
Lots of people sent them emails and none were replied to.
Its like they just didn't care.

Only idiots ignore customer inqueries.
Then we laugh at them when they go under.

[sendler]

OSN Power sells them.
.
Endless-sphere.com • View topic - PROMOTING OSN A123 20ah packs
.
You will want to chose your voltage and stay with it. Any motor you buy for 72v will only top out at half the speed when running 36v. Read more theory at endless-sphere.

[Ryland]

I was pricing out Optima batteries and noticed that they cost about the same as my GBS brand lithium batteries for the same labeled capacity, the Optima batteries of course are heavy, rated for 300-500 cycles and can not handle as strong of discharge without seeing their capacity drop, my lithium batteries are tested to 2000 cycles with 70% capacity left at that time, that's discharging it fully every day for over 5 years and if you don't discharge as fully their capacity stays higher for more cycles.

All batteries need to be balanced, a pack that is never balanced will end up being a short lived pack, if you want to make a pack of lead acid batteries last as long as possible and perform at it's peek then put a battery management system on there! the other option of course with lead acid batteries is to manually balance the pack from time to time with a small charger over night, but without a good battery gauge that connects to each battery in the pack you have no idea what is going on with your pack or if anything is going wrong until you've caused damage.

I spent $1,800 on my 48v 100 amp hour lithium battery pack, it weighs 112 pounds, I then spent another $1,000 or so on the battery management system, LCD display and charger, all of the parts talk to each other so it can charge at a faster rate until a single cell starts to get full then it throttles back until the rest catch up, this feature cost a few $100 extra but it's well worth it.
If I wanted the same capacity with lead acid batteries the pack would weigh 520 pounds, take up 3 times as much space and last 500 cycles or less, I built my motorcycle up with 400 pounds of lead acid batteries and it was unsafe to ride, I have lithium batteries in it now and it's FUN and lighter then stock.

[Daox]

You really shouldn't skimp on batteries. Lead acid is viable, but lithium will be cheaper (in the long run) and lighter and more fun, and and and. There is a reason there haven't been many lead acid EVs over the years, but there are now a good handful of lithium EVs around. If you can't afford it, wait until you can.

[Daox]

Also, I was just checking out your motor and controller selection... I don't think your controller is going to work with you motor. That is a 3 phase AC motor, and your controller is a DC motor controller.

[TurnNBurn]

Originally Posted by Daox

Also, I was just checking out your motor and controller selection... I don't think your controller is going to work with you motor. That is a 3 phase AC motor, and your controller is a DC motor controller.

The mars ME0913 is a DC permanent magnet motor. Where did you get that it was AC?

What is the eBay seller name for the batteries? Have any of you had any bad cells or negative experiences?

[oil pan 4]

I don't know the name of the seller. I bought them a long time ago and they are still in use and work perfectly fine.