Better Battaries for Driver Pratice

[Alan Anderson]

Originally Posted by akoscielski3

How are the chargers not competition legal ??

In prior years, there was a rule that would have fallen between <R34> and <R35> in section 4 of the 2011 game manual. Here is 2009's <R39>:

An automatic battery charger rated for a maximum of 6 amperes must be used to charge the ES17-12 batteries. When recharging the ES17-12 batteries, either the charger provided by FIRST or an automatic charger with an equivalent charging current rating may be used.

The rule was not present this year. Even without a rule specifying so, it's still wise to use automatic chargers that don't exceed 6 amps.

[akoscielski3]

Originally Posted by Al Skierkiewicz

OK,
Let's get some info straight here and in one place.
1. Our batteries are specified by the manufacturer to be charged at 6 amps or less. Battery life can be significantly increased when charged at 1/10 C or about 2 amps.
2. Life is significantly reduced by heavy loads like an FRC robot drawing currents in excess of 200 amps over a two minute match.
3. Charging at high current on our batteries causes internal heating and the possibility of out-gassing and case failure if the vents do not operate.
4. Our batteries are AGM types and the plates within the cells are not as robust as older technology lead-acid batteries.
5. Excessive heat within the battery causes the plates to deform, leading to internal shorts and a variety of other issues leading to lower battery life.
6. Hot batteries during charge can fool many/most smart chargers into producing damaging voltage/current during the charge cycle.
7. AGM batteries are nothing like NiMH, NiCd, LiPO, Li ION or other types and each requires a specific type of charger. Do not mix chargers and battery types.

Thanks for the clarification. Now I know. Although our team does NOT charge them at 15 or 10 amps, so we should not have a problem with any of this