HELP with twin engine battery bank charging system!!
 

I have a 90 powerquest 290 enticer...I added two house batteries to run inverter and fridge about two yrs ago and I am having problems ever since....I know this can be done. I am using blue sea acr's to dump charge over from each cranking battery to house batteries, these batteries are linked together via b+ cable in series then to battery switch and on to inverter. I keep the boat plugged into shore power at home and onboard charger keeps it all topped off. After several hours on the water...it seems like the Alts can't/won't keep up and they start getting HOT...so hot that you can smell them and the "charge" indicators start going lower and lower. I dont ever have dead batteries on the water even when overnighting...but my set up dont seem to work well. I have replaced both Alts with the 65amp Mando's from DB electrical. They test good on the bench but dont know it they are really putting out when they have a load on them and get hot. I know there are alot of boats like mine that have two house batteries added to run house loads....I dont know if the alts are fighting each other or what?? I dont know how to post pics on here but have a complete diagram drawn up of the system. I have had a marine electrician
look over the drawings but couldn't really come up with any better ideas???? Please help or give input. I can email you the diagram if need be...it is much simplier if you can look at the diagram...Thanks for any help fellas!!

[ATTACH=CONFIG]521974[/ATTACH]Scan it into a pdf file then someone can post.

Is it like this. In your case both house batteries would be at position three in parrallel

trying to wrap my brain around this diagram....I would have to completely change my diagram plus change the factory set up on how the cranking batteries are layed out. The way it is now...each engine has its own cranking battery, i can keep them seperate or combine them. Then I am running two house batteries as well. I need to post the diagram but when you say "scan into a pdf file" this is greek to me...sorry!!

so you have it where both ACR's each connect to the common house bank each with 1 lead, with the 2nd ACR leads going to a separate start battery? (Disreagarding the switch and inverter here)


What happens if you have switch set to off when running, do the ALT's still seem overworked? Is the only purpose of the switch to remove the inverter from the system? Is it both Alts or just one that gets hot?

Can you post your pic here? Or send it to me thru PM

Take a picture of your diagram and send it to wobbled at gmail dot com I will post it for you

US1, spoke to you in the past on this issue..Each engine has one crank batt, one house batt and one acr. Acr is between crank and house. The houses are tied in series, this goes through perco on/off switch and to inverter. Both alts get hot. The alts do fine during the day, when running at night with lights on it pulls charge indicators down to 12v even with inverter switch off and they get HOT. Its like it wont keep up when loads are applied, then once they get hot...they shut down??

I think you should disconnect the two house batteries from each other. Then the port motor will charge its start battery then combine with the port house when the voltage reaches the right level, and the starboard side will be the same. I think your alternators are fighting each other through the two house batteries. If disconnecting the house batteries from each other solves the problem the you can install one of these

http://smile.amazon.com/Blue-Sea-Sys...+systems+relay

Which can be wired to stay open when one of the motor is running and can also be manually combined with the switch so you can have a 2 battery house bank when the motors are off. Doesn't have to be this exact switch but basically if my test above solves the problem then you need something like this to let the alternators work properly when they are running and give you the battery capacity you need when they are off.

Deleted. Missed series comment

House batteries are in parallel I hope. You would be better putting both house batteries on one engine or through isolator as shown above. you can not tie both charging systems together through the house batteries except for emergency start as mentioned above.

Since you need the full house battery capacity you do want them tied together but only tied to one alternator.

I would suggest that the house batteries are on the engine that does not have your power steering.