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

[kathyg]

My 24 volt solar system was installed on May 27, 2020. In June 2021, after waiting many months for the installer to check the system, he came, and after much investigation told me that my six AutoCraft Marine Deep Cycle (27dc2) were no good and they they could not hold a charge. Before I returned them to Advance Auto, I took them to another installer and to my auto mechanic who tested them and said all but one was good.

Despite that the one-year warranty had expired, Advance Auto gave me three new batteries. This time they were the brand Diehard and I bought one more to make 4 in total - I think four could hold me over while I figure to what went wrong. So now I have 4 new batteries and I kept three of the old ones- because my second opinions told me they were still good.

Here are my questions:

1. Do these batteries need the water checked every so often? Installer says NO- he says they are maintenance free! We did not check the water for a year. Everyone else says i need to add distilled water every few months. We can see low water levels in some of the cells. Could the lack of water have killed them?
2. How do I know if they were bad from the beginning? Installer says the batteries were bad when I got them. I bought two in Oct 2019 and four more in Feb 2020. The six were installed on May 27, 2020. During the next year I noticed that the batteries were frequently being charged from the inverter/grid even though I beleive my daily use ir about 3.0-3.5 kwh. Some of the batteries had labels saying 2018 and some had labels saying 2019.
3. Could the Controller settings have caused them damage? I called AIMS and they say that the setting of 1000 amp maximum on my MPPT 100 amp Controller was correct . The settings are set to SEALED. See the link to photo album.
4. Can I charge the old batteries and maybe use them, if not together with the 4 new batteries, maybe two of the old batteries (after charging) can be used with with the one 315 watt panel I have in storage. I have been given instructions about how to charge them. Installer says only way to TEST them is to use them. Is that true?
5. INFO: My array is four 315w polycrystalline panels. I have an AIMS MPPT 100 amp controlar and an AIMS 2000w Inverter. I live alone and my usage is about 3.0 - 3.5 KWH per day (I tested and my refrigerator uses exactly 1K per day). I use lights, fans, TV and computer.

I am also trying to decide what to do next. I may install the 4 new batteries on my 24v system to be ready for an outage. In Puerto Rico the grid is not always reliable and we are in hurricane season. But in another forum here I was told not to do anything until I was clear on why the 6 batteries went bad.

Link to photos with more information: https://photos.app.goo.gl/ZDgKkiJLfsTYdkGs8

Thanks, Kathy

 

[MrNatural22]

If they have removable caps on the top they "are not" maintenance free. They are FLA Check the water at least once a week and use only distilled water.
Your installer is clueless.

 

[kathyg]

Yes, they have removable caps where you can see into the water well. Thanks very much.

 

[Substrate]

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.

 

[kathyg]

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.

So you are confirming that it was ok not to check the water in the last year? Wow, you are the first one to say that besides the installer. BTW, he says they got very hot- some electrical tape got melted and and one battery exploded the water over the top of the battery. One battery was tested and showed as dead.

 

[kathyg]

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.

So the Controller should have been set to FLOODED instead of SEALED? Would that mistake cause a problem? Would that explain why they got overheated?

 

[kathyg]

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 installer claims it was the mismatch in age that caused the problem BUT - I had no idea to shop for batteries that had the same month stamped on them and they could gave been inspected and tested before the installation.

 

[kathyg]

I just spoke to AIMS The tech support's best guess is that there was one bad battery among the SIX and that caused the overcharging and overheating. He says the setting on the controller of SEALED vs. OPEN Open Flooded acid is not critical. He said the 100 amp max setting on the controller was correct. Also 80 amp could be correct for extra caution.

 

[GSXR1000]

first i imaged they tested with a battery tester that measured cca no capacity.... so wrong test
second those are "starter type" battery not storage type. so you discharge them to about 30% capacity with killing them. so you can use about 1.6Kwh each night. it looks like you are using much more then that

 

[Tecnodave]

Your installer does not have a clue, your batteries died due to LOM......Lack of maintaince and the wrong batteries for the application. Any battery such as an RV or Marine battery is not truly a deep cycle and as such is not a good battery for cycling use such as solar. If the battery has a CCA (cold cranking amps) it is not a true deep cycle. The true deep cycle batteries are not for starting a car or any engine. Look into the GC-2 batteries as used in a golf cart for a true deep cycle. These are built to put out a steady large current to run a traction vehicle. They are by far the least expensive FLA batteries for solar use. Next step up is the L-16 batteries commonly used in big store floor sweepers, these are 6 volt 400 or so a.h. Even better is the Rolls-Surette and other brands solar batteries. My Rolls-Surette S-530 batteries came out the door at Rolls in July, 1995.......they are a “matched set” with sequencial serial numbers, built on the same day by the same tech. These have been in daily cycling use for over 20 years now and still are matched in Specific Gravity.....This is really the Rolls Royce of batteries......This is how very high reliability systems are built......I do check my water every 2 weeks and only use very high grade distilled water which i check with a TDS tester..(total dissolved solids) YES there is a big difference between cheap distilled and top end brands such as Arrowhead Puritas, you will pay twice as much for Arrowhead Puritas but it is a way better product....

I always suggest using golf cart batteries as a start becuase most people will destroy their first set. Interstate does a good job, these are really rebranded U.S. Batteries as Interstate is a reseller of batteries, not a manufacturer. Also sold at Costco but the Costco variants are of less capacity to sell for less money in a competitive market.

It is quite important to start off with a matched set, do not try to integrate a new one into a used set unless you have no other option.

Flooded lead acid cells need to be equalized and the sealed setting will not equalize....not if , and or but....wrong settings, ignore those inexperienced in such matters and query a power professional in this area


I have worked in battery manufacturing at Alaska Husky Battery in Anchorage Alaska where we built winter batteries that would start your car at 70 below zero so i do have just a bit of experience with Flooded Lead Acid battery building.

 

[kathyg]

first i imaged they tested with a battery tester that measured cca no capacity.... so wrong test
second those are "starter type" battery not storage type. so you discharge them to about 30% capacity with killing them. so you can use about 1.6Kwh each night. it looks like you are using much more then that

I don't beleive these are starter type batteries (I could be wrong). I was told that we are discharging to 50%. During the night (12 hours) I use only 500 watts for the refrig and for some of that time some lights, fan (10 hrs X 50 watts), router and a computer screen. I think it i should be ok.

 

[MrNatural22]

Simple solution to the battery maintenance issue.........Buy an inexpensive hydrometer.

 

[kathyg]

Your installer does not have a clue, your batteries died due to LOM......Lack of maintaince and the wrong batteries for the application. Any battery such as an RV or Marine battery is not truly a deep cycle and as such is not a good battery for cycling use such as solar. If the battery has a CCA (cold cranking amps) it is not a true deep cycle. The true deep cycle batteries are not for starting a car or any engine. Look into the GC-2 batteries as used in a golf cart for a true deep cycle. These are built to put out a steady large current to run a traction vehicle. They are by far the least expensive FLA batteries for solar use. Next step up is the L-16 batteries commonly used in big store floor sweepers, these are 6 volt 400 or so a.h. Even better is the Rolls-Surette and other brands solar batteries. My Rolls-Surette S-530 batteries came out the door at Rolls in July, 1995.......they are a “matched set” with sequencial serial numbers, built on the same day by the same tech. These have been in daily cycling use for over 20 years now and still are matched in Specific Gravity.....This is really the Rolls Royce of batteries......This is how very high reliability systems are built......I do check my water every 2 weeks and only use very high grade distilled water which i check with a TDS tester..(total dissolved solids) YES there is a big difference between cheap distilled and top end brands such as Arrowhead Puritas, you will pay twice as much for Arrowhead Puritas but it is a way better product....

I always suggest using golf cart batteries as a start becuase most people will destroy their first set. Interstate does a good job, these are really rebranded U.S. Batteries as Interstate is a reseller of batteries, not a manufacturer. Also sold at Costco but the Costco variants are of less capacity to sell for less money in a competitive market.

It is quite important to start off with a matched set, do not try to integrate a new one into a used set unless you have no other option.

Flooded lead acid cells need to be equalized and the sealed setting will not equalize....not if , and or but....wrong settings, ignore those inexperienced in such matters and query a power professional in this area


I have worked in battery manufacturing at Alaska Husky Battery in Anchorage Alaska where we built winter batteries that would start your car at 70 below zero so i do have just a bit of experience with Flooded Lead Acid battery building.

Hello: I hear your point. Good info for the future. In the meantime, I do have these batteries which I think I can put to use for a while - as long as I address what caused the first set to fail. Looks like mismatching the batteries may be what caused the problems. Thank-you.

 

[Tecnodave]

If it has a CCA (cold cranking amps) rating on it it is a cranking battery.....all RV /marine deep cycle batteries are cranking/(pretend) deep cycle

Real deep cycles do not have a CCA rating they use 20 ah rate or if they are really good ones the rating is 100ah rating (Rolls-Surette, Crown, Trojan and the bigger DEKA’s)

Rolls-Surette, Trojan and Trojan do not make cranking batteries only true deep cycle and Trojan does make Railroad starting batteries but these are huge, 33” tall etc. 450-500 lbs each 2 volt cell or 6 volt battery, these are a bit big for most uses.

 

[Tecnodave]

kathyg......

do get some good quality distilled water and a good hydrometer. Start with an assement of what you have, top off the cells, charge for 10 hours or so , let sit idle for 2 hours then check each cell with a hydrometer several times....chart the result....repeat the procudere Do set your charger to flooded lead acid and enable equalize on your charger

a really good hydrometer does have a built in thermometer....specific gravity does vary with temperature

THE RIOT ACT..........battery acid is very caustic......have lots of water on hand for a quick wash up, you will not have time to go get water.........have some Arm & Hammer baking soda as a precaution.......don't get it on the batteries

Really decent hydrometer for reasonable on Amazon with built in thermometer...

Amazon.com

david

 

[GSXR1000]

I don't beleive these are starter type batteries (I could be wrong). I was told that we are discharging to 50%. During the night (12 hours) I use only 500 watts for the refrig and for some of that time some lights, fan (10 hrs X 50 watts), router and a computer screen. I think it i should be ok.

as stated CCA are used on starter batteries plane and simple

so you are using 3000 watts per day but only 500w from 6pm to 7am.... if you say so

 

[Substrate]

Right - so wrong type of batteries. Perhaps wrong type of "installer" for suggesting those in the first place for your application.

Note that I'm also NOT suggesting you never take a look at electrolyte levels. Most consumers only put a single one in a vehicle and forget about it and let it die in 4 years.

Here, you are using multiples, and if each one was not charged individually first, a state of unbalance exists when they are put together and charged. It is not uncommon for one to behave badly - ie, one overcharges while one is undercharged due to the imbalance and you have that *dangerous* situation of exploding in the extreme case.

Your installer may also not be trustworthy when it comes to the wiring infrastructure - loose connections, random lengths etc.

In the future, as suggested above, get real batteries designed for your application. These are vehicle starter "marine hybrids", which aren't truly intended for this type of use. And also red-flag your installer for being ok with these in the first place.

 

[kathyg]

as stated CCA are used on starter batteries plane and simple

so you are using 3000 watts per day but only 500w from 6pm to 7am.... if you say so

What I was trying to say is the fan and refrig use max 1000 watts overnight plus a couple of lights and computer monitor for 3-4 hours.

 

[Tecnodave]

The whole reason for equilization is to get all the cells to the same state, it involves overcharging the battery at a controlled rate to force the cells to the same state of charge , with lithium cells it is done by using passive balancing using resistors to bypass the full cells as lithiums can not handle an overcharge. with flooded lead acid the cells are not damaged by the overcharge, the cells will boil off some of the water to dispel the extra input that the full cells have. Only the full cells will bubble excitedly, the weak ones will not....quick way to spot that weak cell. Im using a set of Rolls-Surette and my charge voltage is 28.8 on bulk and adsorb but 31.7 to 32.0 on equalize, too high a voltage for my inverter, I shut down most stuff when i equalize, I do have two completely seperate systems, both with L-16’s but not a matched set so i keep them separated except when big current draws like welding as my 4 kw MagnaSine has a pretty hefty current draw. When charging each set is charged by its own MidNite Classic 150 which can output 70-80 amps with ease.

 

[kathyg]

kathyg......

do get some good quality distilled water and a good hydrometer. Start with an assement of what you have, top off the cells, charge for 10 hours or so , let sit idle for 2 hours then check each cell with a hydrometer several times....chart the result....repeat the procudere Do set your charger to flooded lead acid and enable equalize on your charger

a really good hydrometer does have a built in thermometer....specific gravity does vary with temperature

THE RIOT ACT..........battery acid is very caustic......have lots of water on hand for a quick wash up, you will not have time to go get water.........have some Arm & Hammer baking soda as a precaution.......don't get it on the batteries

Really decent hydrometer for reasonable on Amazon with built in thermometer...

Amazon.com

david

It was suggested to me to put two at a time into service with my solar system and charge them from the grid/inverter. I think the Controller would equalize them. I will look into that Hydrometer - that's new to me. Thanks!