Charging voltage for 16 volt Lithium iron phosphate battery?

[Circlotron]

A friend recently bought a lithium iron phosphate battery for his race car because it is about 40 pounds lighter than the lead acid battery he was using previously. It has gone flat a couple of times because it wasn't charged properly, and we are trying to figure out the correct maximum charging voltage to limit it to. Trouble is, even though the label says it is a 16 volt battery it also says not to charge any higher than 15 volts... I'm thinking the label is for the 12 volt version with permanent printing saying no higher than 15 volts and the added laser printing saying it is the 16 volt version. Anyhow, what should the maximum charging voltage be, and could someone direct me to a site telling info about charging these things?

Edit-> found it should be 3.65 volts per cell. During discharge is 3.2 volts per cell and 3.2 x 5 cells = 16 volts, so 3.65 volts x 5 = 18.25 volts charging.

[theoldwizard1]

Ahh .. the old race car using a high voltage battery !  This typically will only works on race cars used in short races that have no alternator and old fashioned point ignition system.

At one time, they actually sold 7 cell lead acid batteries just for this purpose !  Some people used a 8V golf cart battery and a 6V golf cart battery.

[Circlotron]

Why would it work only with an old fashioned ports ignition system?

[ahbushnell]

A friend recently bought a lithium iron phosphate battery for his race car because it is about 40 pounds lighter than the lead acid battery he was using previously. It has gone flat a couple of times because it wasn't charged properly, and we are trying to figure out the correct maximum charging voltage to limit it to. Trouble is, even though the label says it is a 16 volt battery it also says not to charge any higher than 15 volts... I'm thinking the label is for the 12 volt version with permanent printing saying no higher than 15 volts and the added laser printing saying it is the 16 volt version. Anyhow, what should the maximum charging voltage be, and could someone direct me to a site telling info about charging these things?

Edit-> found it should be 3.65 volts per cell. During discharge is 3.2 volts per cell and 3.2 x 5 cells = 16 volts, so 3.65 volts x 5 = 18.25 volts charging.

you start constant current then shift to voltage limit as the voltage reaches you max value.