xmech2k

Hi all. Haven't been here in quite a while but dropped in to see what's up, then thought of something that this may be a good place to ask.

So I've done it sometimes but not much. Start your car and attach the alligator clips for DC power from your charger to your car battery terminals to charge your lipo batteries. But I've heard people say here and there it's not good. One person I asked said on older cars it's not a good idea as the alternators can't handle the constant load, but it's probably not a big deal on newer cars. Most others just didn't know.

Any thoughts from the experts here? Thanks in advance!
Tom

solentlife

Charging from car is fine as long as care is taken to not drag car battery down low and then not able to start car. Its usually best to start engine first BEFORE plugging in charger as the voltage dip when starter loads battery causes most chargers to default off.
Note that most cars can only supply max 10A through Ciggy Socket and even that can be a problem as any peaks could throw the fuse. If you connect direct to battery - lets be honest - its unlikely you will ever approach a fraction of the amps the battery usually has to endure when starting an engine. But they do not like constant draw over extended periods ... so run the engine and let alternator do the work.

The factor to keep in mind is that its not the alternator or engine that does not like this ... its the cat converter in your exhaust that doesn't ... when we drive - the high engine rpm pushes exhaust etc. at high rate helping to keep clear the Cat box of water and crud. Water being a by product of the Cat box working.

Think of this ... most modern cars today have so much electronics and high power music systems that no longer can you sit waiting for wife to stop spending money listening to car music system without running the engine !!

xmech2k

Hi Solentlife! Thanks for the response. It never occurred to me it might be bad for anything other than the electrical system. I'll have to do some more research down that path. Just want to know everything I can about it.

solentlife

Thousands .. maybe millions of people run car engine while stationary to charge / run items ...... what makes you think your charger will be any different >>

quorneng

It is of course environmentally better to charge your batteries from the mains supply.

solentlife

Be a bloody long lead from my house to flight site !!