Tiny motorcycle battery (how to build an A123 pack)

Here's a battery for your motorcycle that weighs in at under 2 lbs! It's only 4 x 2.5 x 2 inches in size. It has approximately 200 cold cranking amps and 4.6Ah capacity.

This battery successfully cranked my 1200 Sportster 6 times in a row with almost no break or significant charge time (6 cycles of engine start followed by less than 10 seconds of run time, then shut down and repeat). The battery pack showed no sign of slowing down.

The down side? It's a bit expensive (expect to spend $150 - $200).

An R/C battery charger is recommended for initial charging. However, it's supposedly safe to use a 5A car charger with close monitoring (they charge fast - under an hour!). Thereafter, the motorcycle's charge system should be adequate. Do not use a trickle charger (Battery Tender) with A123 packs.

Additionally, these batteries are resistant but not impervious to imbalance. I did not include balance leads on my packs, but they may be worth using in order to perfectly charge the pack from time to time.

Here are the parts sources I promised:

26650 A123 cells, 145mm shrink wrap -- battlepack.com
Dewalt DC9280 or DC9360 battery packs are another source of batteries
Forklift connectors (6382PT) -- Amazon (or McMaster 7043K91)
Hyperion battery bars and balance connectors -- aircraft-world.com
6AWG welding cable -- www.mcmaster.com
6AWG ring terminals - Home Depot
MegaPower 930SR 1S~12S Li-po/A123 Charger + LCB12S -- aero-nuts.com

Category:

Howto & Style

Tags:

• motorcycle
• sportster
• a123
• cell
• battery
• dewalt
• dc9280
• dc9360
• killacycle
• lifepo
• lipo
• electronics
• how-to
• diy
• howto
• instruction

[MaxSachs]

One point I forgot to make: be careful to not solder over the vent holes on A123's when tinning the cells. The video quality is stuck at 480p and I can't see it that clearly but it does appear that the cell vents have been covered with solder, a bad situation should the cells need to vent...

[av8or233]

@MaxSachs I've read conflicting data on those holes. Some say it's ok, others warn vehemently not to cover them. Since they are clearly there for a reason, I was careful to avoid them.

[proaudiohd]

Not watching your commercial.

[av8or233]

@proaudiohd It was a DIY project. I am not affiliated with any corporate entity. In fact, I had a hard time sourcing the materials to make this happen.

[av8or233]

@proaudiohd Then skip the ad.  It won't hurt my feelings in the least...

[av8or233]

@ronmann606 Ok, I see what you meant. Yes, I'm counting on the durability and somewhat unique composition of the A123 cells. There are commercial packs intended for automotive use that are, as far as I know, almost identical to what I've built here.

[Brian500R]

@pornsterwoot

what are you fucking retarded?

[flyboyy]

Thumps up for Great video... I have a few questions for you tho, how does these battery hold up in extreme weathers ? like 20 degrees ? or 100+ degrees ?

what is the life of these batteries before we have to throw them out ? and can we use a battery tender to recharge it when battery is discharged ?

[elpidiovaldez4ever]

how do you balance the battery?

[MaxSachs]

Thanks for posting. 

[NeonGenesisX]

dude great work i learned alot from this video. now im gonna make one my self for my bike ..keep it up

[maakjar]

I can't find a balancing wiring lead diagram for this pack. Do you know how I can wire it or do you have a link?

[maakjar]

Great video really helped me. Thanks

[pornsterwoot]

This is just dangerous. The batteries could explode if they get too hot from the soldering. And it will be extremely hard to solder something on to them.