New batteries needed....

[rcon]

Well I had an unfortunate experience on the weekend, couldn't start one engine and had to come back on one until gained some charge - and I keep an bat in reserve which still didn't help. Well I assume this is the problem and not something more sinister as the volt meter was down around 12.1 when I went to crank.

Anyway, even if the direct cause was low water in my batteries (it was well over 100f so other causes are possible. I'll check Friday), what should I be looking to replace with? Here are some fact I already know/ need to consider

1. I often leave my charger on (not sure why when I think about that!)
2. If I change battery type, I need to do both + charger
3. I have genset
4. I currently have two engine + one genset (new) batteries (do I need to change genset bat?)
5. Twin 4.3l V6s (brand new one started, old one didn't)
6. Don't over night often outside the marina, but have plans for this
7. I like my beer cold
8. I know I need to change charger if I switch to AGM etc

Am I better off with 3 correctly sized bats (I think I have another harness in there) or 2 slightly oversized?

Or, scratch all this and I should just replace with like-for-like? (CHEAP!)

Any and all advice/thoughts appreciated..... Optimas, AGM, etc etc

 

[magstang1]

The first thing you need to look at is the charger.

Is it original? Does it say C Charger, or Charles Charger? If it does, change it. You probably have a single bank charger (unless it has been changed).

Let's start with where you are at, and then you can decide where you want to go.

My guess is that you will probably end up with a new 3 bank charger ($180 ish) and 3 new batteries (Deka about $100 ish per battery)

I left my 3 batteries on and connected to shore power for 2 seasons and I never had a problem. My beer was always cold. This of course was after a little upgrading.

 

[ttmott]

Been doing a lot of work on my boat on upgrading the charging system. You might consider this:Assuming you have three banks (starboard/house, port, and generator) with battery isolators. Get rid of the isolators (old tech and will not allow full charge voltage) and install ACR's between the battery banks then simply tie the alternator outputs to the battery post on the starter motors. This allows any one of the three alternators to charge any battery. Install a new quality three bank charger. Always leave the charger on; this will keep your batteries healthy. For batteries I wouldn't get too carried away; your best value is group 27 flooded lead-acid batteries, one generator, one port and two starboard at least based upon what your use is.