Charging from a vehicle...

[LaurenceGough]

What sort of thing Laurence? Can you link something, just so I can get an idea of what you mean?

Seems a bit silly to me taking a big heavy battery to charge batterys when you have a perfectly good one in the car? I Cant imagine a single lead acid battery will be light enough to carry and charge more than 2-3 packs before needing charging itself?

Thanks for the tip on John, I'm not sure who he is but if it does prove to be a worthwhile thing to do (Me picking up a lead acid) then I'll be sure to go see him and chuck him a few quid for being such a jolly good chap!

http://www.rcheliaddict.co.uk/main-d...ries-free.html

Car batteries are not deep discharge but most leisure batteries are.

Deep cycle battery - Wikipedia, the free encyclopedia

[sacko]

Iv charged my 2x 6s 5000 a fair few times, and I know of others that have.

...at your own risk though.

[dave_g]

Sounds kinda dangerous... I'd avoid it if I were you.

[cjcj1949]

First point is that the state of car batteries vary a lot. You may think you have a 40 AH battery, but especially if you do a lot of miles you could find it's a lot lower. One of mine was 1 AH but started the car ok unless I listened to the radio. It is very difficult to know how much you can take out of a car battery and still be able to start the car. If you want to do this I'd try it at home first with a spare battery or charger available. If you do flatten your battery and the car won't start, you may get it started by just waiting for the battery to recover. The other alternative is to use your lipos as the supply for your charger and use the lead acid/Pb program on the charger. Just putting in an amp hour can be enough to get you started.


The accessory sockets tend to be rated at 10 amps and that should be ok as a load. I can't see the problem with having the engine running and a charger connected as the normal load on a modern car is very high with just lights and heated rear window.


Some chargers will work down to 10V so a very flat 3S lipo at low current will charge your car battery back up. If you fly with other people then it won't be a problem and if you can't take 10AH out of your car battery, you probably have a car electric problem, or do very low mileage.

Car batteries often don't charge very fast either unless new or very flat. It can take many hours to fully charge a battery at 14V-15V.

It's probably a good idea to check the max voltage out of a charger with the car electrics disconnected. One of mine stops at 14V, the other at 15V. I use the 14V one on the car.

[sacko]

[Bamboo]

What about using a Vehicle battery charger that charges your car battery and connect that to your balancing charger?

[xygax]

Paul all though this is doable you need to beware the nominal size for a car battery Is 30 to 50 Ah and that will only support that type of charging current for half to an hour of time and yes the engine is running in this example. The amount of times I have hd to start someone's car due to excessive battery charging I have lost track of.

[Bamboo]

But can you use a mains battery charger and charge them all from home before you go?

[Alfie]

When you put your batterys on to charge from a car, do you run the engine as you charge? Should you? Or should you not?

I know a car battery sits about 14v at idle so dont want to mess my charger up. At the same time I Dont want to be unable to start the car after charging a battery!

I want to charge optipower 6s 3000mah.

you will find a lot of 'dodgy' answers to this.

Firstly, it depends what Alternator is fitted to your car. (i have no idea what car/what engine, or how old it is)?

Assuming you have a recent A/Regulator pack, then connecting youre charger 'after' the engine has been started' and @ idle is fine, the battery is a buffer at this point, and will still buffer provided all six cells are @ equal voltage.

col.

[dillwhacker]

Be warned of starting the car engine part way through a LiPo charge. Doing this killed a mate's LiPo charger recently.
I think because when cranking the engine the car battery voltage drops down to 6 to 8 Volts, and that upset LiPo charger as it tried to maintain the charge rate.

[gazmk2]

I couldn't afford the fuel to run my car to charge at the field! especially as it has to be run on 98RON fuel or higher!

[Mike Sanders]

Buy Andrew Gibbs' guide to lead acid batteries. It will tell you all you want to know and all you need to know.

Very good value. He does one on lipos too. Well worth reading.

[dillwhacker]

I couldn't afford the fuel to run my car to charge at the field!

My RAV4 uses less than half a gallon per hour at tickover charging batts - that's £2.50 an hour...
so shut up and get charging!!

[james_2k]

Very good auto electrician friend of mine told me it wasn't good long term practice to pull the sort of currents I would want to charge big packs fast at from a car,running or not.


If its a company car with company fuel who cares though,mine isn't so I would not do it.


Well any more I mean,my good old ex vectra 1.8 whiłe charging packs with engine running blew the diode pack on the alternator,this sent over current thru the cars electronics and within a month of my new alternator being fitted ecu and other components failed and I decided to scrap the car instead of fix it.


He knows his stuff,he says old cars with old style electrics maybe but anything modern with high levels of sensitive electronic systems you'd be insane.

Haha. Really? Have you seen the amps a large subwoofer can pull from a car battery/alternator? Hint way more than your charger

my jeep has a 180amp alternator. Plus the battery is a bit of a beast too. Being for a large diesel. Maybe if you have a 1litre fiesta it could get interesting with a ridiculous charger setup. But aside from that.

and has been noted above. Car batteries are bad when fully discharged. But as long as you don't do that. It will be fine

[james_2k]

My RAV4 uses less than half a gallon per hour at tickover charging batts - that's £2.50 an hour...
so shut up and get charging!!

Leaving your car idling especially if it's a diesel is very bad for your engine. And in the end will cost a lot more than the fuel used.