Trickle Charger for Battery

[Welshman]

Thanks for the info - i will go ahead with in late Autumn when the car is "rested" for winter!

I tried to charge my last NSX using an Optimate. Odd thing was that after it was switched on i.e. Optimate plugged in to socket and wired up to the battery, no light appeared at all i.e. neither Red, Orange or Green. Have no idea why it wouldn't work. Worked fine on my bikes.

[f2reddy]

I use an old "Davenset" battery charger that must be at least 45 years old, used to be my dad`s. The only modification to it is a rheostat in series with the output to limit the charge currant between 1.5 and 3.5 amps. I`ve left it connected up on the low currant setting to the jump start terminals on the fusebox and engine block for one to two days with no problems.
The warning that is given about charging with the battery disconnected is aimed at modern chargers that try to maintain a constant currant output, or are labelled as "fast chargers" by allowing the voltage to rise thus pushing out the currant to reach optimum charge.
Modern electronics have a low tolerance to over voltage, if the designed supply is meant to be 12 volts then the maximum would probably be 15 to 16 volts, maybe higher in an automotive application because an alternator gives a constant 14.8 volts when running because that is the optimum charge voltage for a 12 volt lead acid battery.
If in any doubt measure the no load output voltage of youre charger, and if its above 15 volts disconnect the battery before charging. Some fast chargers can give 18 to 20 volts or even higher on the cheap imported chargers.