battery recommendation for Isuzu 6BD1

[rockycoastcruises]

I"ve got an Albin 27 Sport with an Isuzu 6BD1 engine and need to replace the batteries since the batteries that came with the boat are weak and failed a load test. Does anybody have a suggestion as to what works well. I currently have two Marine Master heavy duty deep cycle batteries with the rating of
MCA 800
CCA 650
Mins @ 23 amps 225

They serve as the starting batteries and will also be my house batteries. I may have to get another battery to dedicate as my house battery but for now I'm just going with these two.
Thanks

[Mainer]

Hi Joe,

I'm no battery expert, but the stats on your old batteries look excellent for the new ones to match. I have two batteries with similar stats (can't recall exact numbers) on my boat. I always turn my battery switch on "both" when starting the engine, then let my 100 amp Balmar alternator replenish both while underway. When overnighting, I move the battery switch to "2", which is my single house battery. As I probably told you, I also have an electric windlass and a bow thruster, both of which gobble amps. I have 2 golf cart 6 volt batteries (wired together as 12 volts) on a separate battery switch that serves both. I can also switch those batteries to start engine if needed (never used it for that so far). Bought my start and house batteries at NAPA and the 6 volts at a golf cart dealer.
Dick

[DesertAlbin736]

My battery setup consists of three Group 27 90 amp hour dual purpose AGMs. One is the start battery & the other two wired in parallel make up the house bank. My engine is only 24 HP & the starter motor is 1 KW. I think adding a third battery or the pair of 6V golf cart batteries wired in series is a good idea. I got them on sale a few years ago but the prices have gone way up since.

Cabelas battery.jpg

add a battery wiring diagram edit.jpg

I installed the Blue Sea Systems "Add a battery" switch & SI-ACR relay circuit. In that set up the switch is either "Off" or "On" with Start & House circuits kept separate & only connected for charging via a separate charge circuit relay that is energized when it senses the higher charging voltage when then engine is running. There is a override position that can connect "both" if needed. The only problem is there's a slight design flaw in the construction of that switch in that one has to be careful about how much to tighten the nuts on the cable lug posts because if over tightened it can stress the internal plastic posts that the screws that attach the back plate screw into & cause the switch to fail. That happened to me, & although it's under lifetime warranty the COVID pandemic has hosed their raw material supply line & I've been waiting two months for a replacement switch that has yet to arrive. The torque spec for those terminals is 100 inch-pounds, which was like 'oh, now you tell me', since one always thinks that 12 V connections should be tight as possible.

7650.jpg

[rockycoastcruises]

Dick, Thanks for the info. It sounds like I have the correct batteries but unfortunately they need replacing. I'll check out NAPA for my new batteries this spring. I can see setting up a 3rd battery once settled into the new boat. Your 100 amp alternator is a nice addition. Again something to consider for the future.
La Dolce Vita I appreciate the images and description of what you have. You are way ahead of me in getting the battery banks to meet your needs. The golf cart batteries sound like a good addition as they are smaller and easier to handle. Arizona sounds like a nice place to be right now. We're going into the single digits here in Maine and expect a pile of snow on Thursday. Not much boating going on with that weather.

[MoodyBlue]

I have an 87 Sport with the same Isuzu 157 diesel..Since I bought the boat 5 years ago I've been running 2 Group 27 90 amp hour dual purpose AGMs. I start engine on both and use my #2 battery as the house battery. I have never had a problem and I do a lot of overnights but I do keep an eye on the battery levels and will do a quick charge for 15 minutes before going to sleep if I've been running lights, charging phones etc. I also do little tricks like use a battery powered anchor light instead of running off the house batteries just to be safe. I also carry a. WEEGO emergency jump starter just in case but I've never needed it. It's also used for charging phones etc.and has an emergency flashlight. Hope this helps

[coolchange]

got my golf cart batts at Costco...you got to install on your own

I put an AGM 12v for the start...it is so hard to reach that maintenance (water) was near impossible so..no maint!