Originally Posted by The7
Glad if you could tell us a bit more about your A123? Volt? Ah? Cost?
Took me a total order of 5 developer kits for 30 cells @ about $550 plus s/h. From that order I built 4qty 7-cell packs for about 24V @ 2.3AH. Two packs in parallel deliver almost 5AH but with this chemistry that's about like 8-10AH SLA for my application. Unlike SLA, when they're empty, they're empty, can't squeeze any more out of 'em.
I often use just one pack for quick errands around neighborhood but my normal commute requires 2qty 7 cell packs to cover about 10 miles r/t. At the end of day, still plenty in reserve for a couple miles more if needed.
Note - that's with a very efficient Panasonic drive alloy bike, barely tipping the scale at 45lbs with 2qty 7-cell packs. On my heavier hub motor w/throttle, steel frame bike, about 1/2 that range with the same 24V packs. Anyway, one, two, three or four packs is how I discharge 'em in parallel depending on the need.
2qty 3A modified NiMh chargers supply CC so I can charge each pack at a time in under an hour if temps are okay at beginning of the bulk charge cycle. I watch cell balance from time to time with individual cell taps but haven't noticed anything weird yet. Knock on wood...
Originally I was gonna use 8 cells per pack but that peak voltage was just too much for my polite Panasonic unit. It wouldn't turn ON with freshly charged packs and I can't find squat about the Panasonic controller so I dropped the packs down to 7 cells and called it a day.
This project was a year ago and today I think the DeWalt route is the best way to go for cells. Especially since I read about tool service centers giving away warranty exchanges! LOL...
Last edited by BroadwayJoe; 08-10-07 at 04:04 PM.