MMM Voltage-- Is this too much?

[Sammus]

A123 are probably the best case as far as lithium chemistries go, and just happen to have max charge voltage at 7s lining up exactly with that 6s lipo, but with a higher nominal. the huge voltage drops these cells experience probably makes up more than the difference though.

When I read Li-Ion I thought you were referring to the 3.6v nominal cells...A123 are 3.3v nominal, so what li-ion's were you looking at that are 3.2v nominal?

[othello]

Maybe this will help you with your decision.

first minute of a run with 8s1p A123 in a 1:8 buggy/truggy hybrid


The battery pack was fully charged 5 weeks before i did this run. Peak voltage 27.88V, but it usually is higher (28.5V) when the pack comes fresh from the charger. After a minute voltage drops somewhat (25V) but while braking voltage may rise (+1V). After a run with 18-20A discharge on average, the average voltage is 23.8V (a bit lower then 3V per cell).

Seems a bit too risky for me. 7s A123 should be on the safer side.

[BL_RV0]

Yeah. Man, I wish there was a good HV car controller that doesn't cost my life savings to get. Plus with the vehicle I have in mind, mechanical brakes are not an option.