| The car voltage can be anywhere between 12 volts and about 14.6 | volts. When fully charged it will be around 14.6 but as it sits it | will slowly bleed off down to about 12 volts.
To be more specific, 12.0 volts = almost completely discharged, and
12.6 to 12.8 volts (depends on the type of battery) means fully charged. More than 13 volts means the car is running and the battery is being charged.
| Some cars can take weeks to bleed off and others can take days. It | is not a problem.
A car battery ought to be able to last months without charging, but if it's hooked up to a car there's often some little things discharging it -- radio, clocks, alarm etc. But even with those, it should last more than days.
| Devices designed to work as car chargers are designed with regulators in | them to manage the difference in input voltages. It sounds like your Cell | guy knows less about the subject than you do.
Quite likely. He's a salesman ...
`You've got questions? We've got cell phones!' `You've got questions? We've got dumb looks!'
| If it is true about the cell phone and charger I would move on to | another shop and manufacturer as that one is a very poor | designer....
Indeed. But I don't believe it.
Actually, with a NiMH or NiCd cell, the cell phone chargers would just keep charging the battery slowly in many cases, 12v or 120v charger, so in that case it is indeed best to charge and then take it off. But for LiPo/LiIon cells (which are in most cell phones now) the charger has to know when to stop charging, so it's not a bad thing (for the battery anways) to let it charge all the time.
But the voltage regulators found in 12v chargers should be just fine.
To make this R/C related, I saw something clever at
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-- they took cell phone chargers, and added plugs to fit into their `tanic taps' and you can use this to equalize your LiPo packs. Buy as many as you need -- they're relatively cheap.