Single Starter Battery

[Keith Lodge]

Does anyone have any experience with using a single starter battery for both an engine and a generator?

 

I am wondering if it is possible as there will be 2 alternators in parallel across the single battery, albeit both alternators will never run at the same time. From what I understand a non-active alternator sitting across a battery has nil effect, i.e. whilst the engine is not running the alternator has no electrical drain on the system, otherwise the battery would flatten if left unused, and whilst in this state a 2nd active alternator is only like an addtional battery supplying power.

 

The Invertor/Charger we are going to use has a 2nd 12v output to trickle charge a starter battery which, if we had seperate starter batteries, would only charge one of them, if we didn't want the added expense of splitter diodes. The domestic batteries are charged from a 2nd alternator on the engine, so the engine starter circuit is completely seperate. The generator will charge the domestic batteries via the Invertor/Charger.

[Sir Nibble]

No problem. Twin alternators are sometimes used and even if both running will not cause problems. Engine start batteries need little charge anyway.

Consider, if your starter draws 350A (lots) and cranks for 10 seconds (lots) that's 0.025Ah, (buggerall).

[Keith Lodge]

Many thanks for the reply, it is what I thought anyway, but just needed confirmation of it. Your comment about the low charge required is why the Invertor/Charger has the 2nd starter battery output which is rated at only 4amps.

Edited May 18, 2007 by Keith Lodge

[Sir Nibble]

So that would take 6 minutes to put one start worth of charge in!

[Keith Lodge]

Give or take a microsecond or so, hahahahahaha.

 

Cheers.