Trickle Charger for Battery

[mcibuk]

I used to use an "ACCUMATE" trickle charger on my last car which kept the battery at 100% when the car was not in regular use. The charger is hooked up permanently to the car without disconnecting the battery from the car and is easily disconnected when you want to use the car. It is a wonderful device!
I now want to use this charger on my NSX but the car's manual advises against using battery chargers without first disconnecting the main terminals, as damage to the EMU could be caused.
The manufacturer of the Accumate charger reckons there won't be a problem but before taking the plunge i would really like to hear if anyone has any negative experiences with this type of charger.

Many Thx.

[mcibuk]

I presume from the lack of any responses that you must all use your cars every weekend in winter and that you have no need for such battery charging devices!

[Kevin]

Not so true. There are a few people I know that use a tricke charger without problems. I haven't myself so I can't comment from personal experience.

[DamianW]

I was interested in what people use too. I have an Optimate here I used to use on my Elise, but wondered what people did for the NSX.

[Mike_L]

I do try to use the NSX at least once every 2 weeks, even if only for a few miles.

In case you don't know, there is a +ve jump lead point in the engine bay in the fuse box to the left of the water coolant resevoir, saves having to take the spare out to jump start the battery if you ever do lose its charge.

[DamianW]

Ok, well at the weekend I fitted the little plug thing for my Optimate. I've used the Optimate on an Elise and a motorbike and never disconnected the battery on either. I switched it on briefly and nothing fried, but haven't had it on any length of time. I'll probably put it on this week sometime as I haven't used it much ... I'll let you know.

[DamianW]

Just to let you know, I had the NSX on the Optimate last week ... so the fact it started and got me to Castle Combe indicates it probably hasn't fried anything :D

Dead easy to fit the plug, and Optimates can be had for something like 30 or 40 quid from a motorbike dealer.

[mcibuk]

Thanks for all the comments - much appreciated!
At this point i'm also driving the car every week so the battry is OK - it's during winter months when i will need to use so i will feel much happier now!

Thanks again

[nicjwin]

i have had my optimate for 3 years used every winter with n problems at all

[mcibuk]

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

[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.