Help choosing new batteries?

[mxjohnson]

Hello all.

I recently bought a Pearson Triton with an A4. She has two batteries, House & Starting, that are ten years old and need to be replaced. They're Interstate SRM-24, labeled as Deep Cycle as well as 690 MCA. They're 11 x 7 x 9.5 inches, placed under the step box just forward of the motor, with not much ventilation and not much extra room.

My first thought was to run out and buy two more batteries, perhaps even the same model. Before I do, I thought I'd see if anybody here has a better idea. Currently (no pun intended) the only way to charge the batteries is by running the engine. The alternator is an API 55w model.

In the next year, especially, we'll be spending more time at the dock than out cruising. The house battery don't power much beyond the typical lights, VHF, stereo, and the depth finder. All the pumps are manual & everything is turned off when I'm not on board.

My first concern is over the placement of the batteries. I've read that flooded cell batteries need good ventilation when charging. They're situated in a cubby off the engine compartment, and there aren't any sensitive electronic devices in there.

My second concern is how best to charge them. Running the engine just to charge the batteries strikes me as inefficient. I don't want to leave shore power hooked up 24/7, but I'd use it to charge the batteries from time to time. I'd also be willing to try solar panels, but I've heard so much conflicting advice I'm hesitant. Either it's a good way to preserve your batteries, or ruin them, I guess.

I sure would appreciate any advice about how I should charge the batteries, and even more to the point, whether I should consider something other than replacing the old batteries with two more just like 'em.

Thanks in advance!
Mike

[rescuesailor]

Don't know if this will help but i can relate my own experience. My last boat which had a very simular electrical set up to what you described had two batteries, one for start, one for house. I had a 110v charger that I left plugged in 24/7. Big mistake! Even though I had a so called smart charger it essentially cooked my batteries which i had to replace within a year. My current boat came with two gel batteries. This boat has been on the hard for 5 years while it goes through a complete rebuild. These two batteries have sat in my garage or on the boat to power a bilge pump for rain water. Both have held up very well with no problems. On occassion I have run them down to very low voltage. A quick recharge brings them right back. Well worth the extra cost in my opinion. Currently I swap the batteries out on my boat. There is no way to charge them on the boat. I am investigating putting a small solar trickle charger on them. I have a friend who swears on his solar panels, and he has convinced me that it is much safer than shore power when left unattended. Something I have feared since having to replace two cooked batteries. The added benefit is that if you are not hooked to shore power you have less chance of being affected by someone elses electrical nightmares, including the marina's. Anyway thats my two cents worth.

[forrest]

I have just one battery on my boat (house). Its a 4D lifeline AGM. I am a big fan of AGMs, no adding water, no venting issues, charge and discharge more efficiently and best of all no spilling (I've lost more than one pair of pants to wet cells). They are pricey, but I think worth it over wet cells.

I have mine plugged into shorepower all the time and it stays topped off. I have not had a problem with my charger (guest procharge 5/5) overcharging and it is nice to have it all ready to go when ever I want. We can go pretty much a week on that one battery without having to worry about a charge, but we don't have much draw.

One think I have heard about Gel cells is that you can hurt them pretty bad by charging at to high a rate, so some charging systems might do damage to Gels. However, this is pure hearsay and speculation so don't take my word for it.

Anyways, my two cents is for AGMs. Good luck


Forrest

[Figment]

First: Welcome to the asylum.

Second: GREAT boat name.

On to business....
Don't worry too much about the current battery location. No, you can't really get a proper battery enclosure and yes it's REALLY tight to get two batteries in there, but it's worked for decades. We've all considered various other battery locations (not that one has a long menu of options on a Triton) and they all have their drawbacks. The boat wants the weight forward, but that means long heavy ($$) cable runs, etc. Moving them into the very forward end of a cockpit locker isn't a bad idea, but this is a project which is easily de-prioritized.

My personally favored solution (pretty far down on my "someday" list) will be to leave the starting battery where it is, and have something like a 4D house battery elsewhere.

In terms of locations and charging system, I'd leave things alone for this season at least, until you can get some real experience with just how much power you use. Running the engine at the dock for 30 minutes or so to top off the batteries isn't the end of the world, and I've come to believe that an A4 is happier when you run it every time you go to the boat, whether you actually leave the dock or not.

If your power needs are as modest as you suggest, why bother buying two batteries right now? You really could get by with just one. I have for the past three years of mostly daysailing not really cruising at all.