Battery capacity

Oct 2, 2014
46
Benneteau Oceanis 361 from 2001 Gruissan, France
On my 361 I got 3 batteries, that I am going to exchange with AGM batteries, which I heard should be the best type. One start type and two consumption types.

We are in the spring off for a 5 months tour around the Balearic Islands and want to do as much anchoring as possible to keep the cost down.

I guess I can fit in three 110 amp batteries. Will that be enough/sufficient or should I install two more batteries?

How long motoring will it take to fill up my batteries?

I heard about a Sterling inverter, which should make the alternator 4 times more efficient/faster. Does any of you have experience with them.

Claus
 
Jun 4, 2004
287
Beneteau Oceanis 352 NYC
I've read, heard and experienced that AGMS are not as good as we've all been told. I think Maine Sail did a write up on their performance vs wet cell batteries.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
I have 3, size 31 batts on my B323, 105 each. If you plan to anchor alot, I suggest getting solar panels to keep your batteries up. Sure, you can run your engine at speeds higher than idle, say 1800, to charge, but unless there is a load (in gear), you engine will suffer. Motoring will charge up you bettery some, but not "top it off" to 100% unless you go a long way. Or, yeah, more batteries as you say.

Inverter has nothing to do with battery charging. An external charge controller would be a big help. I Agree AGM is not the way to go. They are too picky about a charging regimine. And, they need 100% charging, which it does not sound like you'll be doing if just running the engine to do it.
 
Oct 2, 2014
46
Benneteau Oceanis 361 from 2001 Gruissan, France
Sorry, I meant a charge controller. I am going to use a small inverter for my laptop. Thanks for your input.
Claus.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
read Maine sails write up on external regulated alts and regulators it will help you decide what you want to do look for Balmar regulators in Musings with Mainesail or compass marine ..a lot of good info there to digest
 

Rick I

.
Jan 6, 2007
414
CS36Merlin and Beneteau 393 - Toronto
I second the suggestion re not getting AGMs. I made that mistake some years ago and they only lasted two seasons as I was never able to fully charge them while cruising. I'm back to flooded lead acid and couldn't be happier. As far as I'm concerned AGMs on a cruising boat is just throwing money away. If you're plugged in at a dock every night they're fine but for cruising, forget it.
 
Jun 2, 2004
153
Beneteau 393 Lake Texoma, Texas
Realizing your question is about batteries, you can indeed increase your battery capacity, but also consider reducing your drain. We replaced all of our interior lights and the anchor light (one of biggest draws of power overnight with non LEDs) and found that our power needs were dramatically reduced.
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Realizing your question is about batteries, you can indeed increase your battery capacity, but also consider reducing your drain. We replaced all of our interior lights and the anchor light (one of biggest draws of power overnight with non LEDs) and found that our power needs were dramatically reduced.

Bingo! Conservation is an excellent way to increase your daily usable capacity. LED lighting is one of the best ways to save a lot of Ah's..
 
May 13, 2013
42
Beneteau Sense 50 San diego
In general, while away from the dock your batteries will run between 75 percent and 50 percent of capacity. That is you will only get about 25 percent of total capacity before having to recharge. Don't count your engine battery as that should never be used for house usage. For example, if you use 100 amps a day you will need 400 amp capacity and will run your engine with 50 amp charger once a day for two hours. Friends with solar universally wish they went with more.
 
Oct 2, 2014
46
Benneteau Oceanis 361 from 2001 Gruissan, France
Thanks for all you great input. I will now go for ordinary wet batteries of a good quality, because with the 4-5 times higher price on the AGM´s I am still fine, if they only should last me two years. I will also install 200 AH extra. Thanks.
 
Nov 23, 2009
437
Beneteau Oceanis 361 Clipper --
Just to add...
You are planning as you said to install 3 110amp batteries. Most probably 2 in front of the engine and one at aft port side cabin. You don't need 110amp just to start the engine. You better install a 70amp for this and "save" some space to install a bigger than 110amp battery for services.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Just to add... You don't need 110amp just to start the engine. ...install a 70amp for this ....
Except that sometime down the road one of the two house batteries will die. It is better to have batteries in the same bank "matched". The "engine" batt could be placed into the house bank, then get an "engine-sized" battery at that time. My 2$.

I have 3 group 31s, and I rotate starter duty via the battery turn-switches.
 
May 13, 2013
42
Beneteau Sense 50 San diego
Agree. All batteries should be same type. Also not a fan of AGM. Cost mostly. I do not agree with the ability to switch to use the engine battery as a house battery. The only time you will likely do it is when the house battery has run down. And I don't like "all" to start the engine either. I will forget the first time I turn it off. If I ever need to use a house battery to start engine (have had to do it once), I temporarilly rewire.