Using a multi charger connected to a mains car battery charger

[Mike Ellis]

Can anyone advise me that if connecting my new 4 battery multi charger with 80watts per channel for lipos and nicads, and thats designed to connect to a 12 volt battery to charge the 4 batterys, will be ok if its attached to a Car battery charger that's plugged into the mains, as to power the multi charger instead of it just clipped onto a 12volt battery ?

My brain cell can't make up its mind !!

HELP !!!!!!!!

Mike Ellis. LMA 652

[Steve Perry]

4 x 80 watt channels = 320 watts

320 divided by the nominal 12v of a car battery = 26.66 amps

Even if you have a car battery charger rated that high, I would suggest connecting a car battery to the charger at the same time.

[Mike Ellis]

Ok Steve, so I would be ok to connect up the mains charger to the nicad and lipo charger as I thought , and all should be ok ?

Thanks

[Steve Perry]

I strongly suggest adding the car battery as without it the peak voltage output of a car charger could be 20 volts or higher !

[Mike Ellis]

Oh !! Lets see I have it right !!
I connect a car battery to the car charger ( which I havent got at present !!) then also connect the lipo/nicad charger to the car charger ?
The car charger I have can charge at 12 or 24 volts so using the 24 volt setting wouldn't be any use then ?
I also have a 12v jump start that garages use to start cars with a flat battery, there is a cigar lighter socket on the rear so could I I
Use that item and plug the lipo charger into the cigar socket ?

[Steve Perry]

12 volt setting, car charger to battery, lipo charger to battery.

I would not use the lighter socket as if the charger is not powerful enough then it could pull the power backwards through the bat charger from the car battery.

If you mean one of those things on wheels that a garage wheels out to start your car, then I would play safe and not use it

Interestingly 2 local garages are now using a hand held lipo device about about the size of two cigarette packets to jump start cars.

[Mike Ellis]

Thanks Steve, I do appreciate all your valued help.

[david whiston]

Mike
take care I did just this, and the load into the charger was sufficient to get so hot it nearly melted the plug that goes into the charger from the battery ,,,

Chargers are not my strongest area but I do advise caution !!

[Barrie King]

Mike as Steve says you really need to check the rating of your car charger, it will need to be continuously rated at about 30 amps to do the job. Most normal car chargers are only rated 6 or 10 amps.

[Mike Ellis]

Thanks to everyone who have made helpful comments on here, however !!! I have come across the AC power source thats also made by my new chargers manufacturer,so that it can be connected directly into the mains 240v supply ! and its actually rated at 30 amps ! So At least I now have the complete set up.