Battery Maintenance

[D Bell]

Question - Does it make sense to rotate batteries to prolong their life? I've heard to replace all at once every 2-3 years. Wondering if rotating will help.

2000 340 Sundancer. 2 Starboard for engine and generator, 2 Port for engine and house. I have to think the house (or the entire port bank) gets the most abuse. Thoughts?

 

[Pgeee]

I’m assuming if they are wired correctly so that the charge is balanced across them all it makes no difference

 

[Stray Current]

The biggest thing you can do is keep the water at the proper level if they are flooded and ensure that you are using the right automatic battery charger. That keep the terminals clean.

I take care of several hundred batteries for standby generator systems and I have some that are going on 10 years old that the customer won’t replace because they keep testing well. I got almost 10 years out of a set of deep cycles in the boat. I had two boats ago. If you’re not beating them up real bad and deeply discharging them regularly, they should last for quite some time.

 

[D Bell]

So here I am. 4 batteries. Starboard side 2 are Generator and Engine, each. Port side 2 are wired parallel for port engine and house. Have had shore power on, heater and refrigerator running. 3 bank charger is all green lights.

Port side wouldn‘t crank. Checked water (fine) and tried a jump box. Nothing but clicks. Used Emergency Start and got it running. Gauge says alternator is pumping out 14 volts. Ran 20-30 mins to fully warm up and get juices flowing.

Don't know the battery age, but on my watch since 3/22. No problems in the 2 seasons we have enjoyed thus far. Didn’t see anything in 2021 maintenance records we got from previous owner. Is this the symptom of a battery/batteries going down? Interstate group 27’s. Thanks.

 

[Lazy Daze]

Besides the brand, what type of batteries are they?

Generally speaking, with a good brand and proper type for the use, you should have no problems getting at least 5 years out of them. Likely more if you're looking after them and keeping them on charge.

There's usually a stamp or sticker on the battery somewhere that says when it was made.

Yes, failing to start an engine is indicative of failing batteries - but other things could cause that, too. Charge the batteries FULLY (20 minutes at idle doesn't do it) and then LOAD TEST them. Start with that -- and of course checking for the date stamp - depending on age, you might just want to replace them.

No, I don't think it's worth it to rotate them.

 

[D Bell]

It‘s 4 Interstate 600 CCA wet batteries. All the same. No stamp or sticker. Charger is 15 amp, 3 bank from Bass Pro XPS.

Would you go with the same batteries and stick with the same wiring configuration? What about doing deep cycles on the port bank?

Given only the Port side seems to be going out, would you do only those 2?

We have not had any problems in these first two fairly active seasons, batteries were on the schedule this year.

 

[ttmott]

Rotating batteries - In my mind rotating could extend the overall ships batteries life if one bank is getting cycled more and/or more deeply than another. The math part is when and how often to rotate....
I agree with others that typically replacement on combination start/house should be around 5 or 6 years for all lead acid style batteries. Obviously, batteries that are always on the charger will last substantially longer than ones that are cycled deeply routinely.

 

[techmitch]

I think that charger is too small for a 340. Also, is it a charger/converter as it should be?

 

[Yendor]

I think Mitch is likely correct about your charger being to small.

If your port batteries are wired parallel and are fed as 1 of the 3 banks from the charger, that 5a may well not be enough to sufficiently top off 2 group 27 batteries and keep them happy for the long term.

If I'm understanding correctly (and I way well not be), you have the Starboard batteries connected to the charger as 2 banks (1 each), and the Port batteries as 1 bank. You also say that you suspect your Port bank gets the most abuse. If that is the case, maybe you should change the arrangement so the Port side is set up as 2 banks with the third on the Starboard side.

Naturally, that doesn't address your initial question(s), but may help prevent a recurrence. I would have the port batteries load tested, replace them if need be, and then address your bank setup.

 

[ttmott]

I think Mitch is likely correct about your charger being to small.

If your port batteries are wired parallel and are fed as 1 of the 3 banks from the charger, that 5a may well not be enough to sufficiently top off 2 group 27 batteries and keep them happy for the long term.

If I'm understanding correctly (and I way well not be), you have the Starboard batteries connected to the charger as 2 banks (1 each), and the Port batteries as 1 bank. You also say that you suspect your Port bank gets the most abuse. If that is the case, maybe you should change the arrangement so the Port side is set up as 2 banks with the third on the Starboard side.

Naturally, that doesn't address your initial question(s), but may help prevent a recurrence. I would have the port batteries load tested, replace them if need be, and then address your bank setup.

It will top off the batteries but take eternity. 5 amp would be maintenance only; not for bulk charging.

 

[Lazy Daze]

It‘s 4 Interstate 600 CCA wet batteries. All the same. No stamp or sticker. Charger is 15 amp, 3 bank from Bass Pro XPS.

Would you go with the same batteries and stick with the same wiring configuration? What about doing deep cycles on the port bank?

Given only the Port side seems to be going out, would you do only those 2?

We have not had any problems in these first two fairly active seasons, batteries were on the schedule this year.

What type of batteries are they, though? Deep cycle... starting?

600CCA isn't bad - but on the small side. If they're starting batteries then that's part of the problem... they're taking that big hit when starting the engine (which they're meant for) and then being used for house loads and they're not really meant for that. But if you switch to DC's, they're not really meant for starting the engine. So it's a bit of a give and take - ideally, each engine has it's own starting battery and then you have a separate bank for the house.

That charger is definitely smaller than what would have been there originally - and I believe it's kind of an "entry level" charger. IS IT IGNITION PROTECTED? The charger may or may not be contributing to the issue, though - it depends on how hard the house batteries get used and the amount of time they spend on charge.

What is the charging profile for that charger... can it supply 15a to one bank?

Not having issues the first two years doesn't really tell anything - of course you didn't! Otherwise you would have asked this question 2 years ago

The stamp/embossment/sticker isn't always right on top - often down low on one side.

 

[BlueYonder]

Test the batteries. They can show good voltage and still not be able to produce the required cranking amps.

Your charger most likely will put out a maximum of 15 amps across the 3 outputs combined. If two of the banks are demanding 1 amp each, that would leave 13 amps for the 3rd bank. Proper charger size should be based on amp hour capacity, not CCA. As a bare minimum, the charging amps available for the bank should be 10% of the total bank amp hour capacity. If the 2 batteries in your port bank are group 27 and have 90 amp hours each, you should have a charger capable of charging the bank at 18 amps. Due to the charging profiles on modern smart chargers, a lower amp capability doesn't just take longer to charge, the battery may not reach a proper charge at all.

 

[White Shadow]

Could it also be something as simple as a bad/loose ground on the port bank (port engine)? Then when using the emergency override you would be using the starboard circuits. Of course 100% agree to test the batteries too.

 

[D Bell]

I think Mitch is likely correct about your charger being to small.

If your port batteries are wired parallel and are fed as 1 of the 3 banks from the charger, that 5a may well not be enough to sufficiently top off 2 group 27 batteries and keep them happy for the long term.

If I'm understanding correctly (and I way well not be), you have the Starboard batteries connected to the charger as 2 banks (1 each), and the Port batteries as 1 bank. You also say that you suspect your Port bank gets the most abuse. If that is the case, maybe you should change the arrangement so the Port side is set up as 2 banks with the third on the Starboard side.

Naturally, that doesn't address your initial question(s), but may help prevent a recurrence. I would have the port batteries load tested, replace them if need be, and then address your bank setup.

Thank you Yendor. You’re right. 1 bank is gen, 2 is Stbd engine, 3 is 2 batteries in parallel form bank 3 for the port engine and house.

Wouldn’t I want to leave the 2 bank setup on the port to get the most amp hours for the house?

 

[D Bell]

What type of batteries are they, though? Deep cycle... starting?

600CCA isn't bad - but on the small side. If they're starting batteries then that's part of the problem... they're taking that big hit when starting the engine (which they're meant for) and then being used for house loads and they're not really meant for that. But if you switch to DC's, they're not really meant for starting the engine. So it's a bit of a give and take - ideally, each engine has it's own starting battery and then you have a separate bank for the house.

That charger is definitely smaller than what would have been there originally - and I believe it's kind of an "entry level" charger. IS IT IGNITION PROTECTED? The charger may or may not be contributing to the issue, though - it depends on how hard the house batteries get used and the amount of time they spend on charge.

What is the charging profile for that charger... can it supply 15a to one bank?

Not having issues the first two years doesn't really tell anything - of course you didn't! Otherwise you would have asked this question 2 years ago

The stamp/embossment/sticker isn't always right on top - often down low on one side.

Thanks Lazy Daze. I’ll check more throughly for date info (and type). Regarding the charger size, our use is weekends only with 5 days between “load”.

…..and “load” is not that bad. We have iPads and battery fan for comfort. We start the gen for 120 to make coffee and top up in the mornings. Really use battery for music and little night light to read before bed. Does that help? What size charger is appropriate?

if I have to replace batteries, what would be the optimal “types” to use and where (bank set-up)?

 

[Yendor]

Wouldn’t I want to leave the 2 bank setup on the port to get the most amp hours for the house?

While maybe not technically incorrect, we are using the term 'banks' here to reference two different things, and that is creating confusion. If we substitute "Legs FROM the Charger" for banks in my previous statement, that may help.

If I'm understanding correctly (and I way well not be), you have the Starboard batteries connected to the charger as 2 banks Legs FROM the Charger (1 each), and the Port batteries as 1 bank Leg FROM the Charger. You also say that you suspect your Port bank gets the most abuse. If that is the case, maybe you should change the arrangement so the Port side is set up with 2 banks Legs FROM the Charger with the third Leg going to the Starboard side.

The arrangement that I was implying would be preferred is to have one leg of the charger going to the Starboard batteries and to have the other two legs of the charger going to the Port batteries. This would give you a dedicated charging leg for the house battery, which is something you currently lack. (no pun intended) Doing so would additionally isolate the Port engine starting Load from the house battery so it is not giving up and losing that reserve right out of the gate.

If your Charger will allow different profiles for each of the "legs", this would also allow you to replace the House battery with a Deep Cycle battery which would perform more effectively for longer.

Again, not meaning to imply this will entirely solve your problem (your charger is small), but would be a preferential setup to what you currently have.

 

[D Bell]

While maybe not technically incorrect, we are using the term 'banks' here to reference two different things, and that is creating confusion. If we substitute "Legs FROM the Charger" for banks in my previous statement, that may help.

The arrangement that I was implying would be preferred is to have one leg of the charger going to the Starboard batteries and to have the other two legs of the charger going to the Port batteries. This would give you a dedicated charging leg for the house battery, which is something you currently lack. (no pun intended) Doing so would additionally isolate the Port engine starting Load from the house battery so it is not giving up and losing that reserve right out of the gate.

If your Charger will allow different profiles for each of the "legs", this would also allow you to replace the House battery with a Deep Cycle battery which would perform more effectively for longer.

Again, not meaning to imply this will entirely solve your problem (your charger is small), but would be a preferential setup to what you currently have.

With one "leg" going to the Starboard side, would I hook up the Gen and Starting battery in parallel to get the charging off that one leg?

By separating the 2 port sides for a starter on one leg and a deep cycle on another, am I loosing the amp hours that 2 12v's in parallel produce?

Are dual purpose batteries worth it?

PS - Literature tells me the charger will deliver 5 amps per leg. No ability to share. It is a cheap one.

 

[Lazy Daze]

Bell, take note to the question I asked above about ignition protection. That is paramount to everything else at this point.

I suspect your boat already has the capability (wire size) to run a larger charger as it would have came from the factory that way. It probably had a 30a charger - but check your parts manual. A ProMariner ProNautic-P 30a would be an excellent choice if you wanted to upgrade (or at least get back to normal). Ideally, a 4-bank charger would be best. But you can get away with hooking your port side bank up with one charger lead - just make sure the two batteries are exactly the same and fully charged before doing so.

"Banks"... a "bank" is a single battery or group of batteries that function as one battery. For example, the (2) port side batteries are "one" bank.

In addition to the recommendation I gave above for re-wiring for best use... If you didn't want to do that, DP batteries have traditionally been hit or miss. But more recently, Deka has a group 27 and 31 DP (preferably the 31) that has been used by many in the fishing world of boats and seems to be doing very well. I wouldn't hesitate to use those on your port side.

 

[Scott215]

I have 5 years on my interstates and they are still testing fine

 

[D Bell]

Bell, take note to the question I asked above about ignition protection. That is paramount to everything else at this point.

I suspect your boat already has the capability (wire size) to run a larger charger as it would have came from the factory that way. It probably had a 30a charger - but check your parts manual. A ProMariner ProNautic-P 30a would be an excellent choice if you wanted to upgrade (or at least get back to normal). Ideally, a 4-bank charger would be best. But you can get away with hooking your port side bank up with one charger lead - just make sure the two batteries are exactly the same and fully charged before doing so.

"Banks"... a "bank" is a single battery or group of batteries that function as one battery. For example, the (2) port side batteries are "one" bank.

In addition to the recommendation I gave above for re-wiring for best use... If you didn't want to do that, DP batteries have traditionally been hit or miss. But more recently, Deka has a group 27 and 31 DP (preferably the 31) that has been used by many in the fishing world of boats and seems to be doing very well. I wouldn't hesitate to use those on your port side.

Bingo! Thanks Lazy Daze. My parts manual list a 30 amp as OE - CONVERTER, 30AMP 120/220VAC 50/60HZ FLYBACK - honing in on my problem.

Are the batteries that have enjoyed these two+ years of mismanagement under my pitiful charger now, toast?