GCinDC wrote:Just since we're on the topic of the battery, a couple of Q's..:
- what C ratings do those prismatic A123's have for discharge/charge?
- So it's ONE 24s pack made of a 15s and a 9s subpack, with one BMS, right?
- How low will the BMS let an individual cell go? 3V? Is it a signalab?
- Did you get one charger or two? How many amps are those?
- How wide are the packs? How wide is the bike frame at it's widest?
- Does cell man have a site or just work off email?
Should be a nice weekend! Have fun and RECORD!
Have to get ready for work, but here's a few answers as I know them to be.
1.) Continuous discharge rate should be round 12-15c?
Specifications
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Normal Voltage: 3.3V
Capacity (1C to Vmin=2.0V): minimum 18.5AH, typical 20Ah
Dimensions(mm):7.2 x 161 x 227
Weight (kg): 0.495
Volume (l): 0.263
Operating Temperature: -30c to 55C
Storage temperature: -40C to 60C
Number of Cycles : minimum 300, typical 2000
Max Discharge (SOC and Temp dependent): 300Amps
Wh/kg: 130.5
Wh/Cell: 64.6
Wh/Liter: 245.6
Self Discharge @ 25C: <2%/month
Nominal Voltage and maximal / minimal discharge voltage (recommended and critical) 3.3 nom, 3.6 max, 4.0 critical. 2.0V min, 1.0V critical
Nominal Capacity: 18.5Ah min, 19.6ah nom
Internal resistance: 2 mOhm nom
Specific Power (nominal, W/kg): 2400
Maximal current discharge rate: 300 cont, 750 peak
Charge conditions: maximum voltage, charge current CC-CV to 3.6V. 300A max, 600 peak
2.) Yes, just based on my frame limitations with the highest capacity pack as a goal, with Cell Man's relentless input, we determned that the best/maximum config was 24s using these 20ah packs. Based on the actual cell dimensions, + the shrink wrap and safety packing, it turned out that the 15s/9s sub-pack arrangement was the answer.
3.) There is one single 24s BMS. I do not know yet how far it lets each cell go. I am sure Paul (Cell Man) will be able to answer that. Don't now if its a Signalab. The BMS handles HVC,LVC, and cell balancing when charging.
4.) I have one charger, connected by one anderson connector, capable of charging at 6 amps. He also offers a 4 amp charger. The charger is a little bigger than any of the chargers i have had before, but I could certainly still throw it in a back pack. If I needed more range, say for example if I decide to ride to see you in DC and opportunity charge along the way...
5.) Pack Dimensions are listed above, but the shrink wrap insulation should add at least 1-1.5mm. I had Paul reduce the amount of packing due to my frame design and the security it provides for the cells. My frame at its widest point is 113mm. the 15s pack is 115 mm. Crank set clearance on each side is 4-5mm. Real tight.
6.) You have seen Paul's website, but the bulk of my conversations (24+) were through email.
At the end of the day, This pack can handle any amount of continuous amps
I intend to draw from it, now or in the future. I am not expecting to pull more thn about 45 amps continuous from my 5303, and at most for 30-45 seconds or so. In the future, if I go for a slower wind and decided to bump the amps to say, 80-90

it will do just fine, as will my controller. It has a BMS that will keep the cells in check. Stable chemistry, and ll I need to do is plug in the charger.
A bit heavier than Li Po, but less hassle, and my girl is big boned anyway.....
edit - just proof read my post. made a few typos....