Trojan Boat Forum

JWRAPE...your setup looks good....and yes. connecting two batteries in parallel like that with no isolation is an acceptable practice.as long as your chargeing system can handle the double chargeing output.its done all the time in the small diesel pickup world. It is preferred that they be identical in age and type when replaceing but NOT necessary.Charge Leveling occurs between batteries. its perfectly normal...even with batteries that are in series (and under load). I have been to large battery backup sites and I'll tell you this...when one dies or gets weak,they dont change them out all at once. The problem with this setup or any setup utilising more than one cell is what happens when one cell starts to die .To state it as simply as possible,when a cell dies it is most often due to internal shorting . The cell becomes a load rather than a source.
Replacing both at the same time makes it easier to predict when its going to happen. There IS a simple tool that makes the prediction easier. I have
been useing one of these tools for well over 40 years.Its called a hydrometer and its available at Walmarts for less than five bucks.With 30 cells on board, it would be useful to get one and learn how to use it.As a cell dies its specific gravity changes.

disclaimer: Not useable for gel cells or batteries that are actually sealed with non removeable caps nor batteries that have developed a sulfide coating(sat dead for too long).

Over the weekend I bought a new 500CCA Marine Starting Batt. to put on the Generator and removed the 2 Marine Deep cycle batteries.

I isolated the house battery and the engine battery BUT when I connected re-wired the connections the motors would not turn over without flipping the emergency switch. So I wired it back to the original way but in doing that realized that both of my engines are wired to the same starting battery and the house battery and the windless are wired to the other battery.

SO, I know my next step is to wire the house and the windless to the two extra deep cycles I have sitting there. I have to get some longer cables.

Don't know what to do about the ONE battery used to start either engine. It works perfectly now but if you seperate the engine connectors and put them on two batteries, they won't turn over without the emergency switch pushed. So I'm kinda at a loss of why that is the way it is. I'm not too concerned about it.

I'll just put the deep cycle batteries on the house instead of the Cold Cranking battery and then it will solve my discharging issue when the radio is left on....

Oh I got the Generator running perfectly as well.....

I would run the windlass from one of the starting batteries... the draw is quite high and better put on a starting battery which should be being charged since the engine is running, right?

jwrape wrote:Don't know what to do about the ONE battery used to start either engine. It works perfectly now but if you seperate the engine connectors and put them on two batteries, they won't turn over without the emergency switch pushed. So I'm kinda at a loss of why that is the way it is. I'm not too concerned about it.
Oh I got the Generator running perfectly as well.....

Any chance that one of the engines is not grounded to it's battery?
You do have a +ve and -ve from each engine to each starting battery? and both (all) negatives linked also?

Glad to hear the genny is running......

Yea, all the grounds are grounded to a bus and then back to the engines.

Ok, the Windless will stay on the starter battery.