Charging golf trolley battery whilst in car

Are you sure that used diodes?

Bill

Yes. Much better than relay control from the alternator warning light, which was the old way of doing it.

Bill

I've always said that if you need fast reliable charge of an aux battery whilst on the move the only way is a 500W true sine inverter followed by a decent charger, say a 20A one. Even then the charge rate rapidly drops off and there's no sensible and safe way of preventing that.

Bill

I use a 24 to 12 one to charge the 12V battery in my motorhome. Works fine. Output is 14.2V.

Bill

Probably the alternator or dynamo output was adjusted to compensate for the voltage drop. A 0.6V drop on the wiring (never mind from a diode) will affect charge rate and charge finality very severely.

Bill

The market seems to favour voltage sensitive relays. These have the advantage of being adjustable. They also incorporate protection if the aux battery is totally flat and a delay in switching both on and off which is good.

Bill

It's pointless if you're going to go to mains charging after getting home. The two hours in the vehicle will make no difference whatsoever to the battery condition in the morning. The two hours charge will simply slow the mains charge rate a bit. Been there done that got the Tee shirt and the acid burns.

Bill

If it's a quick charge battery connector yes.

Bill

But if your mains charger is half decent it would charge the battery from nothing to full overnight anyway.

I've been towing disability scooter around for donkey's years, tried all sorts to charge them up.

Bill

Impractical.

No it wouldn't.

Bill

I’m so glad that we have someone who is prepared to take the time to engage a troll in witty repartee. It so enhances the group…

Tim

yes, although I never dismantled the unit to check

How does a decent camper van do it? Recharge the aux battery when on the move?

IIRC, a single diode? Just to prevent reverse flow?

charles has brought this to us :

So in all probably a voltage controlled relay then?

No it wasn't a relay

Plenty of splt charge diode units can be seen on the internet. There's even an old Lucas one on EBay!

From Wiki:

A split-charge diode is an electronic device used to enable simultaneous charging of multiple batteries from one power source. The device prevents current from flowing from one battery to another while enabling the batteries to be continuously connected.

While the original devices used diodes to charge the two batteries, while keeping them separate from each other, most devices now use other configurations in order to avoid the 0.7V drop which reduces efficiency and increases power dissipation. However the name still remains.

Bill

Very dodgy thing to do with the engine running! For many reasons...

Bill