power source thoughts

[winterdog]

hmmm. getting a good power source for our bikes seams to be the where alot of the cost is.
have i calculated wrong or are the battries just 15(48v 20Ah) of these bad boys 18650 Rechargeable Lithium LiFePO4 Battery, my calculation are probably off by a factor of 10
and could probably burn your house down
has any one built there own powersource from this stuff

davidk

 

[flecc]

I'm afraid the error is very much bigger than 10 times David. Fifteen of those in series would only give the 48 volts at the same 1350 milliamperes of capacity. To get the 48 volts 20 Ah of capacity you mention would require 15 x 15 of them, i.e. 225 batteries, 15 in series by 15 in parallel. That would cost a whopping $1552.50.

In any case you couldn't use a regular e-bike charger on a combination like that since they warn about the charging voltage of 42 volts, and additional battery management circuits or isolating Schottky diodes would be needed to cope with the parallel batteries when in use.
.

 

[Tiberius]

hmmm. getting a good power source for our bikes seams to be the where alot of the cost is.
have i calculated wrong or are the battries just 15(48v 20Ah) of these bad boys 18650 Rechargeable Lithium LiFePO4 Battery, my calculation are probably off by a factor of 10
and could probably burn your house down
has any one built there own powersource from this stuff

davidk

Love this image

Don't try this at home.

I have a set of LiFePO4 packs that I built, and several members on here have packs from Ping, which are also LiFePO4. But neither of those use these cells.

Nick