DasDouble said:
A Guy told me that the cells wouldnt work correctly for high voltage like 74 Volts, 20Ah, 22s. What do you guys think? Want to buy the Sanyo ones because people here say they are as good as Panasonic.
Voltage does not matter, its the discharge you need to pay close attention to, I believe both these current batteries are 8 to 10A of discharge. Unlike a 25R battery which is much much more then that. Keep in mind however that the more battery strings you put in parallel, the higher your discharge can be and obviously the higher your Ah.
Simple example using 3.3V nominal, 3.5Ah and 10Amax discharge batteries.
#series and 2 parallel, whatever voltage and 20Amax discharge at 7Ah.
1S-10P then you have nominal voltage of 3.3V and 100Amax discharge at 35Ah.
10S10P is 33Vnominal and 35Ah at 100Amax discharge
30S30P is 99V, 105Ah and 300Amax discharge.
*So you buy/build a pack in terms of VOLTAGE to suit your controller, and/or speed you want. This is the series part, 1S, 10S, 30S. Then you want a certain Ah for the distance you want to travel, this is the parallel part or P in the numbers given. 1S10P, 10S10P, 30S30P. Discharge is yet another factor. Too low a discharge battery and you will burn the batteries up, going up hills, too heavy a load on bike, etc etc etc.
Voltage is added in series. Ah is added in parallel.
I struggled with the discharge aspect myself, but you add it just like Ah in parallel. So if you have 3.5Ah batteries as my examples are, for the current battery Tumich is selling.....then 10S and 10P would indicate 33Vnominal for 3.3Vnominal batteries, 35Ah (3.5Ah for each battery times 10) and a discharge of 100Amax, because the batteries are rated for 10Amax discharge. These are just examples, if your batteries are different then substitute in different numbers. I will summarize again.
Voltage is added in series, and disregarded in parallel. 10S10P you go 3.3Vnominal x 10 = 33Vnominal pack.
Ah is added in parallel, disregard series. So 10P would be = Ah of battery times 10. 3.5Ah x 10 = 35Ah.
Example given: 33Vnominal 35Ah pack.
Discharge is similar to Ah in formual/calcuation. If you have 10S10P of 10Amax discharge batter
Example given: 33Vnom. 35Ah and 100Amax discharge.