Originally Posted by
Doc_Wui
The weak point is probably going to be your car's accessory (cigar lighter) port. They can handle 120-150W, but if the contacts are corroded on either the socket or your plug that number goes down and the connector heats up.
I charged my battery in the car last winter with a 36V2A charger. That's about 80W max. I had a 500W inverter. It handled it fine, but the connector did get fairly warm. I've had that inverter for many years The label says to not go over 150W with an accessory plug. I would have to connect it direct to battery to get 500W out of it.
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Yep, exactly what I was thinking. I have a small inverter I picked up at Radio Shack ( many years ago ) when Radio Shack was still in business. Can't find it at the moment but I'm thinking it might be rated somewhere around 100 -120 watts. The charger for the ebike battery is outputting 42 volts @3.1 amps. That's about 130 watts. That's a lot of power to be drawing from your cigarette lighter outlet. My basic worry would be that it might blow the fuse on the cig. lighter outlet or even worse that the plug in the lighter outlet would get hot enough to actually melt the plastic on the plug ( or even the socket itself ).
Going forward it I do decide to take a camping trip somewhere and have no access to line power I might decide to buy a better inverter, one at least rated to 500 watts. I'll also make sure it has the clamp connectors that will allow direct connecting to the car battery. A good inverter should have it's own circuit breaker or fuse setup. Of course if I use something like this I'd have to let the car run while the e-battery is charging or I'm sure it would likely kill the car battery in no time flat. Certainly not the ideal situation as gas is not exactly cheap.
Nope, not going to mess with the cigarette lighter socket. I can safely use that for charging my phone and my 8.4 volt bike batteries so I'll not take chances with the e-bike battery.