Why did my SIX marine batteries (27DC2) die in less than one year?

[Tecnodave]

yes, dont overcomplicate doing too much at a time, 2 batteries at a time if you are 24 volt system. if plates are showing fill the cells to 1/2 over the plates as acid mix grows in volume as the specific gravity comes up. a good cell should come up to 1.260 s.g. but what is important is that all cells will be within .020 of each other, any cell that is consistently below 1.100 is dust.....that battery is kaput... my L-16,s are all within .010 of each other....the 2 sets are not the same. The primary set is Rolls-Surette S-530 solar batteries, the other set is Interstate traction batteries made for those floor sweepers that you see in the big grocery stores, way less expensive than Rolls less than 1/2

Here is my comparison of lead acid batteries

Car starting battery......should start your car in 15 seconds, after that the alternator does all the work, the battery is along for the ride, it contributes nothing

Golf cart and other traction battery.....Its job is all day long with few breaks, it gets no help from the alternator and it will not see the charger for many hours unless you get out and push......lol

 

[donbamo]

1. Never leave FLA batteries in a discharged state. If you won't be using them, have them connected to a float/trickle charger to keep them topped up. If you let them sit in a discharged state for more than 24 hours, you may state noticing drop in capacity due to sulfation.
2. Always check the water level. Don't fill up too much. Just above the plates and only top up after the battery is fully charged.

 

[donbamo]

Don't mix old batteries with newer batteries. They shouldn't be more than 6 months apart.
Create a seperate battery bank with the old batteries.

 

[donbamo]

Lastly it appears your battery is dual purpose battery(not a true deep cycle). Any battery with CCA or MCA is not a true deep cycle battery.

Dual purpose batteries should not be discharged more than 20% (maybe 30%) or you risk damaging them. A true deep cycle battery can be discharged to 50% (some 80%).

 

[kathyg]

Plenty of ways to go wrong here. One is mixing and matching new and old stock batteries from an auto-parts store, where they commonly sit on a shelf and hard-sulfate.

The "maintenance free" flooded batteries basically have extra electrolyte in them so that unattentive consumers can get 4 years of life without checking. But you can do better if the caps do come off and checking every now and then.

These are FLOODED "maintenance free" which emulate a phsical seal for the consumer, but the setting in your SCC should be for flooded. This is where some confusion comes in with all that maintenance-free jargon.

The second biggest problem is usually that of unbalance if they were just slapped together, and placed into service especially if mix-n-matched in age.

The best thing you can do at this point is to give each one a proper charge *individually* with an AC charger, (because solar for an initial charge may not be sufficient) - let them finish charging, and then connect them up for service as normal. And consider changing your charge controller to the flooded setting.

thank you

 

[Texas-Mark]

Don't mix old batteries with newer batteries. They shouldn't be more than 6 months apart.

I know this is what a lot of people say, but I have a mix of batteries that have a 2 year spread and they are all still going strong (oldest one is over 5 years). And these are just regular marine deep cycle batteries. IMO, as long as you do proper maintenance and don't over discharge them, they will last many years. Yes, in a perfect world all batteries would be close to the same age, but that is not always feasible or economical.

 

[MrAubin]

Just get lithium batteries. Solve your problem. Or one big one. I think. I'm ordering one of these in March. https://volthium.com/en/product/battery-wallmount-24v-200ah-5-12kwh/

 

[12VoltInstalls]

these are just regular marine deep cycle batteries. IMO, as long as you do proper maintenance and don't over discharge them, they will last many years

Yuppers.
I’m not scoffing at the rules or being a know-it-all smart-britches, either, but I’ve been using Everstart Maxx for various things for years with good results.

No water, deep cycling, and long periods of discharge will kill a lead acid battery quickly. At current pricing, Group 27s at five years cost ~$14/yr. Is lifepo better in a bunch of ways? Sure. But fla is still a workable and moderately inexpensive when you plan for them to last.

wildhat guessing for OP: you might need a couple more batteries for longevity. You should never go below 12.04/12.06V. Ideally you’ll be above 12.3V at dawn. 12.04V for these cheap batteries is 50% discharged. Below that is where damage can begin to occur.

Bad day for me to give an example because things are defying logic this morning- the sun’s been up an hour?ish but overcast and somehow I’m at 12.8V. 12.3-12.4 is more normal. Overnight load is only the 1/3-size fridge.

 

[RCinFLA]

Couple of recommendations on buying lead-acid batteries.

Avoid any sitting on shelf of store longer then three months. Look at date code on battery..

Take a DVM with you and don't buy if less then 12.5v open circuit voltage. Preferrably not less than 12.6v.

Don't series stack batteries with more then one month difference in date codes. Preferrably same month date codes.

Precharge batteries that will be series stacked to full charge before you stack them. 13.8v initial charge, then 2 hrs at 14.2v.

 

[Texas-Mark]

Just get lithium batteries. Solve your problem. Or one big one. I think. I'm ordering one of these in March. https://volthium.com/en/product/battery-wallmount-24v-200ah-5-12kwh/

That's a lot of money ($3500) for just one battery. I can replace FLAs of equal voltage/capacity nearly 6 times for that cost, and I won't have all of my eggs in one basket.

Sure, I know people are rolling their own for less, but even doing that, the price needs to come down another 50% or so before I am willing to go that route. And if I need to replace a FLA in a pinch, I can run down to Walmart instead of waiting months for the slow boat from China. Not knocking lithium, just not seeing it as cost effective for me at this point.

 

[wholybee]

This is a very though article explaining flooded deep cycle batteries.

What is a Deep Cycle Battery? - Marine How To

Light Cycle vs. Deeper Cycle NOTE: This article deals with FLOODED marine batteries, not AGM or GEL batteries. The Problem: The problem, as I see it, is one of dishonest marketing where multiple battery types wear the same clothes (sticker) and will perform differently when

marinehowto.com

Things that will quickly ruin a flooded battery. One or several of these might have caused your problem:
Frequent discharges to 50% or lower. Occasional is ok, but with lead batteries you what to use a little of the available power as practicable.
Undercharging/Not charging to 100% often. Doesn't need to be every cycle, but a couple times a week is a necessary. And they should float after reaching full charge for a while. Not just immediately discharge again. It is very difficult to meet this requirement with solar.
Not checking/adding water frequently enough. If the plates become exposed, you have damaged them. If you catch it right away it isn't too bad, but if left exposed the damage can be significant. I would suggest weekly or biweekly checks until you get used to how much water your system uses, as it will vary depending on load and charge rates. You should check and record specific gravity with a hydrometer when you add water. Changes in SG warn as capacity is reduced, and when to equalize.
Overcharging. Not as common or bad as undercharging, but frequent or severe overcharging will damage cells.

LifePO4 are much more expensive, but because you are not limited to 50% of the capacity, and because they are much more forgiving with undercharging and not needing to add water, they are usually much more economical in the long term. Buy a smaller battery, spend less time and money on maintenance and lasts 5-10 tames as long.

 

[kathyg]

Just get lithium batteries. Solve your problem. Or one big one. I think. I'm ordering one of these in March. https://volthium.com/en/product/battery-wallmount-24v-200ah-5-12kwh/

thanks but the link does not work.

 

[kathyg]

This is a very though article explaining flooded deep cycle batteries.

What is a Deep Cycle Battery? - Marine How To

Light Cycle vs. Deeper Cycle NOTE: This article deals with FLOODED marine batteries, not AGM or GEL batteries. The Problem: The problem, as I see it, is one of dishonest marketing where multiple battery types wear the same clothes (sticker) and will perform differently when

marinehowto.com

Things that will quickly ruin a flooded battery. One or several of these might have caused your problem:
Frequent discharges to 50% or lower. Occasional is ok, but with lead batteries you what to use a little of the available power as practicable.
Undercharging/Not charging to 100% often. Doesn't need to be every cycle, but a couple times a week is a necessary. And they should float after reaching full charge for a while. Not just immediately discharge again. It is very difficult to meet this requirement with solar.
Not checking/adding water frequently enough. If the plates become exposed, you have damaged them. If you catch it right away it isn't too bad, but if left exposed the damage can be significant. I would suggest weekly or biweekly checks until you get used to how much water your system uses, as it will vary depending on load and charge rates. You should check and record specific gravity with a hydrometer when you add water. Changes in SG warn as capacity is reduced, and when to equalize.
Overcharging. Not as common or bad as undercharging, but frequent or severe overcharging will damage cells.

LifePO4 are much more expensive, but because you are not limited to 50% of the capacity, and because they are much more forgiving with undercharging and not needing to add water, they are usually much more economical in the long term. Buy a smaller battery, spend less time and money on maintenance and lasts 5-10 tames as long.

I have 4 new marine batteries with the same date (March 2021). I will be installing them soon. Honestly I have been somewhat frozen with fear that I will not follow the proper steps. Now I have to just do it! I checked the water (they were ok). I charged them all with a car battery charger about a week ago. I tested them today and they are 12.5v. 12.6 or 12.8. I have been told the water in marine batteries do not have to be checked frequently - so many opinions- I will check every few weeks (like you say - maybe more frequently until I learn how mine are running). The hyrdrometer is something I will look into after I get the system running. I do not understand how the batteries could get overcharged. Thanks,

 

[kathyg]

I know this is what a lot of people say, but I have a mix of batteries that have a 2 year spread and they are all still going strong (oldest one is over 5 years). And these are just regular marine deep cycle batteries. IMO, as long as you do proper maintenance and don't over discharge them, they will last many years. Yes, in a perfect world all batteries would be close to the same age, but that is not always feasible or economical.

Thanks! what is "overcharging"? How does that happen?

 

[Texas-Mark]

Thanks! what is "overcharging"? How does that happen?

I had said not to over discharge them, but one can also overcharge them you don't set the charging parameters correctly. Most charge controllers and chargers have a lead-acid (FLA) setting. But also if the batteries are in a hot location and you do not have a battery temperature probe, you may have to dial down the charging voltages a bit.

 

[kathyg]

I had said not to over discharge them, but one can also overcharge them you don't set the charging parameters correctly. Most charge controllers and chargers have a lead-acid (FLA) setting. But also if the batteries are in a hot location and you do not have a battery temperature probe, you may have to dial down the charging voltages a bit.

The AIMS tech support tells me to set the Controller to Flood Battery and set the max charge current to 60 amps. I have 4 batteries set up in series to make a 24 volt system. My system is connected to the grid for charging---in case this helps: Aims says to set my inverter "current control knob" to below 75%. I also will leave my inverter dipswitch #1 on position 1 - for a SOC of 50%.

 

[wholybee]

I have 4 new marine batteries with the same date (March 2021). I will be installing them soon. Honestly I have been somewhat frozen with fear that I will not follow the proper steps. Now I have to just do it! I checked the water (they were ok). I charged them all with a car battery charger about a week ago. I tested them today and they are 12.5v. 12.6 or 12.8. I have been told the water in marine batteries do not have to be checked frequently - so many opinions- I will check every few weeks (like you say - maybe more frequently until I learn how mine are running). The hyrdrometer is something I will look into after I get the system running. I do not understand how the batteries could get overcharged. Thanks,

A hydrometer is a critical tool to make an FLA battery last. How often you add water is entirely a result of usage. When I had FLA batteries (which were "marine" if there is such a thing-and installed on a boat) , I added significant water every 2 weeks. I worked them very hard. When I was at the dock not using them, they could go a few months without water.

 

[12VoltInstalls]

been told the water in marine batteries do not have to be checked frequently

You were told wrong. Check weekly, use distilled water to top as necessary. After a while you’ll learn/ know how often you will to check them.

A marine battery if one were to describe a single “difference” is a flooded battery with heavier plates that withstand vibration and shock better. These heavier plates won’t deliver big-high amps like a starting battery but they will (or should) deliver moderate/low amps for a longer period of time repeatedly.
But no matter what if the plates are out of the fluid electrolyte you have compromised the battery.

 

[kathyg]

You were told wrong. Check weekly, use distilled water to top as necessary. After a while you’ll learn/ know how often you will to check them.

A marine battery if one were to describe a single “difference” is a flooded battery with heavier plates that withstand vibration and shock better. These heavier plates won’t deliver big-high amps like a starting battery but they will (or should) deliver moderate/low amps for a longer period of time repeatedly.
But no matter what if the plates are out of the fluid electrolyte you have compromised the battery.

I appreciate your reply. I am now trying to position the batteries so it is easy to look into the cells. I think that will make it more likely I will do it. To positon them correctly, I will have to get some longer cables, which is another challenge that I am working on. Thanks!

 

[12VoltInstalls]

To positon them correctly, I will have to get some longer cables,

Or you could do as I do and leave it difficult and hard to do and cuss yourself out every month? No, don’t do that. I need to check mine again and it’s been three years of difficulty cuz I’m dumb