I Only Have Two Batteries - Which Batteries Should I Use?

[LifesAnAdventure]

I have a Pearson 38' that has only room for 2 batteries. I spent last season on a mooring and killed my batteries because I wasn't fully charging them. Should I use 1 battery for starting my 3hm35F Yanmar and the other for lights? I have been searching the boat to install more batteries but the designer of the boat used every nook and cranny available.
If I intall only 2 batteries which type would be best?
If I install 1 or 2 more batteries which type would be best?
If I install a solar panel to help keep my batteries charged while on the mooring which solar panel and system is best?

Thanks in advance for any advice you all have for me.

Joe

[Cowboy Sailer]

We have all three of our AGM batteries in one bank and use it for everything including starting our 30 hp Yanmar. That size of a diesel does not require a lot of starting current. We use less than one amp-hour to start our engine. We use about 140 amp-hours per day to power our refrigerator, anchor light at anchor or autopilot and tricolor while sailing.

[Hydra]

Before trying to add more batteries, I suggest that you reduce your consumption. If you don't have a fridge, that's easy: just change all your light bulbs for LED.

Since I changed, I have no problems anymore: when I cruise, one battery is sufficient for engine starting (Nanni 2.50 HE, 14hp), lights (including nav lights), GPS and VHF. I only have to run the engine 1 hour every other day. I also added a digital voltmeter, to keep an eye on this battery. My next objective will be to add a second battery but I have first to find some room for it.

Alain

[four winds]

I don't have answers for the OP. But I have similar issues.

I have a Pearson323 with two 105ah AGMs on a 1,2,all switch. I have the original alternator as well. (55 amp)

I've been out of the marina for two weeks now. And according to what I read here, I'm probably killing my AGMs with the factory alternator. Can't afford a Balmar kit at $800 just yet.

Before, when I was on the hook for a night or two I would use Bat 1 exclusively. For the last two weeks I have done this also. Since I don't want to charge at no load, I do a couple of laps around the bay at near full throttle after an afternoon of sailing. If I don't sail I don't use the TV, or computer, or MiFi that day. No fridge, watermaker, etc. So the anchor light, fresh water pump, and one interior light is all I use those days, while listening to a battery operated radio.

I haven't allowed the battery to go below 12.2v so far. Checked after a resting state for a while. This is the best I can think to do at this time.

[Cheechako]

OP: the answer is really the biggest batt's that will fit. If you go Gel or Glass mat...you should be able to put more most anywhere....under the sink!! :>) On a mooring , a small $50 trickle charge solar charger ought to keep them up.
four winds: I used a gel 4D cruising for 3 years mixed with wet cells and a high out put ample power regulator set for wet cells. I had no issues at all. I dont know about Glass Matt...? but I doubt if a stock regulator will stay at the peak voltage long enough to cause a problem... maybe someone else knows better...

[redcobra]

Originally Posted by four winds

I don't have answers for the OP. But I have similar issues.

I have a Pearson323 with two 105ah AGMs on a 1,2,all switch. I have the original alternator as well. (55 amp)

I've been out of the marina for two weeks now. And according to what I read here, I'm probably killing my AGMs with the factory alternator. Can't afford a Balmar kit at $800 just yet.

Before, when I was on the hook for a night or two I would use Bat 1 exclusively. For the last two weeks I have done this also. Since I don't want to charge at no load, I do a couple of laps around the bay at near full throttle after an afternoon of sailing. If I don't sail I don't use the TV, or computer, or MiFi that day. No fridge, watermaker, etc. So the anchor light, fresh water pump, and one interior light is all I use those days, while listening to a battery operated radio.

I haven't allowed the battery to go below 12.2v so far. Checked after a resting state for a while. This is the best I can think to do at this time.

I solved part of my problem by substituting two West Marine 6V 225Ah batteries for the 110Ah 12V. Takes about the same space L and W but are 6" higher so they fit in the same place. I also went with a bigger alternator and smart regulator.

[four winds]

Originally Posted by LifesAnAdventur

I have a Pearson 38' that has only room for 2 batteries. I spent last season on a mooring and killed my batteries because I wasn't fully charging them. Should I use 1 battery for starting my 3hm35F Yanmar and the other for lights? I have been searching the boat to install more batteries but the designer of the boat used every nook and cranny available.
If I intall only 2 batteries which type would be best?
If I install 1 or 2 more batteries which type would be best?
If I install a solar panel to help keep my batteries charged while on the mooring which solar panel and system is best?

Thanks in advance for any advice you all have for me.

Joe

Forgive me, I did not intend to take the focus away from the OPs questions.

I do agree with an earlier post that the Yanmar (at least mine) starts fine on the AGMs, set to all, or one or the other battery. Starting is not a problem for me. Even after a night on one AGM, using the TV and other stuff, the engine starts on that same battery fine.

I have considered putting both AGMs on one bank. And adding a starting battery on the other bank. Then using a charge combiner to charge the starting battery after the AGMs are topped off.

Ideally I'll add a high output Balmar with external regulator in the future.

I have a small 15w solar panel that I haven't used yet. I don't know if it really would add any value to my setup, maybe it would.

I'd like to do a ice box conversion to 12v fridge and add a big solar cell.

[zeehag]

the best solar panels are the ones that are not too pricey and work/ is the cnnections not the panels. mine are all from used other sources--i have unisolar, kyocera, and some other one,all over 3 aamps rated and allllll dangnear free to me......LOL..and my blue sea mppt controller is bombawesomewonderful.(that was 350usd 6 yrs ago..LOL) goood luck. it aint what ye has but how ye use it......

[offgrid64]

It's important to make room for batteries even if you have to get creative. On my catalina 38, the original design didn't have a large battery area. I cut up the plastic to make room for an 8d agm, then put a 2nd 8d agm a few inches away actually in the salon below the dining table. I put it in a west marine battery box and U bolted the box to the bulkhead. Since it's all under the table nobody even notices it. I have a dedicated starting battery for bank 1 which I put behind a false drawer under the sink. So just get creative and don't settle for low capacity.

[HopCar]

When looking for a place to add batteries, don't forget that you can install AGM's on their side. By doing this I was able to slip my batteries into a place that they wouldn't fit if they were upright.

[H/V Vega]

Try the Lifeline AGM batteries. Those are seriously good batteries and the people who make them are right there to help out with settings etc should you need. When putting in new batteries remember the boats balance
We use 6 X 255 amp Lifeline AGM's and are happy as can be with them. Mind you we have 3 fridges going sometimes when we are carrying medical supplies so need loads of power for those puppies.

[mystic_voyager]

Originally Posted by LifesAnAdventure

I have a Pearson 38' that has only room for 2 batteries. I spent last season on a mooring and killed my batteries because I wasn't fully charging them.

Joe,

When I purchased my Pearson 38, it was obvious the previous owner was very fond of being "off the grid".

In addition to the engine alternator the ENERGY GENERATION consists of one 400w wind generator, one 100W solar panel over the hatch, and two large 135W solar panels above a set davits. All this electrical energy was stored in NINE batteries as follow: STARTING BANK #1 (1) type 27 starting battery in the sail locker; HOUSE BANK #2A (2) GC2 batteries in series in the sail locker, HOUSE BANK #2B (2) GC2 batteries in series in the aft berth; REEFER BANK #3A GC2 batteries in series next to the engine under the sink, REEFER BANK #3B (2) GC2 batteries in series in the settee near the water heater. Add to this a dizzying array of manual switches, an auto battery combiner and isolators.

All the batteries are flooded lead acid batteries.

Since purchasing the boat I did away with HOUSE BANK #2B.

I would not have thought to make the modification the previous owner made and I would not recommend going to these extremes, but I have become quite accustomed to going very long periods of time (many days) without hearing the sound of my engine. BTW, I make hot water with solar bags.

I've seen other boats my size that have mounted solar panel over a cockpit bimini, but I'm going to try to resist the urge to add more solar panels.

I thought of naming the boat "TWELVE VOLT MAN" -- after the Jimmy Buffett tune of the same name ("He don't need no charge card; Just give him a die-hard; And he'll make sparks fly round your head").

All interior lighting is now LED.