Advice on finding best new coach batteries

[RVwife]

Our OEM coach batteries are toast. I've been looking into what we can get that will fit into the space available in our 2018 Axis 25.3

Maximum space to fit 2 batteries side by side is 26 x 7 x 9.5.

Our rig does have a solar panel. We do like to boon dock, but are still relative newbies at RV life

Thor tech support said just go to Walmart and pick out your favorite type 27 battery. Easier said than done. Our local store only carries the Everstart and it will not fit our space. If I order the Mighty Max (which has a large number of poor reviews) via Walmart.com it appears to not be returnable if it doesn't fit well either.

So, recommendations please - preferably deep cycle, long life, maybe AGM.

Thanks.

[ducksface]

Walmart batteries are great.
I don't know about size difference.
A 27 is a 27 almost, if not actually, by law.

And
My rv uses 24's and should have the same steps/battery bay as yours.
You Might have been told some bum information.
If yours does indeed use 27's and the Walmart won't fit, the 24's will fit. There is no significant difference between 27 and 24 other than dimensional. There is only a negligible laboratory difference other than size.

I have never heard of nonreturnable Walmart batteries.

[Beau388]

Originally Posted by RVwife

Our OEM coach batteries are toast. I've been looking into what we can get that will fit into the space available in our 2018 Axis 25.3

Maximum space to fit 2 batteries side by side is 26 x 7 x 9.5.

Our rig does have a solar panel. We do like to boon dock, but are still relative newbies at RV life

Thor tech support said just go to Walmart and pick out your favorite type 27 battery. Easier said than done. Our local store only carries the Everstart and it will not fit our space. If I order the Mighty Max (which has a large number of poor reviews) via Walmart.com it appears to not be returnable if it doesn't fit well either.

So, recommendations please - preferably deep cycle, long life, maybe AGM.

Thanks.

Common old sizes battery group 22, 24, 27, 29, 30 and 31 are all about the same width and height. The difference is in length; group 22 are 9" long and the group 31 is about 13" long. The heavier the battery the more amp-hours. A good place to start until you know what you want is: <https://www.batterystuff.com/kb/tools/bci-battery-group-sizes.html>



Walmart sells a complete line of combination batteries labeled as Marine/RV Deep Cycle in the EverStart brand which I think are a great value for a 4-5 year battery life. I have two of those in the group 29 size which barely fit.
They are flooded, but I have a watering system. They will probably outlast me. Yes Trojan have a longer life the Everstart, but I will be dead or have a new coach in 4 years. AGM batteries are better but cost twice as much, but they can be shipped UPS or by Amazon..

[sanjaun2]

Everlast batteries are not very good. If you wanted a good price on better batteries try Sam's club or Costco. I recommend going two 6vdc instead of two 12vdc.

[ducksface]

Originally Posted by sanjaun2

Everlast batteries are not very good. If you wanted a good price on better batteries try Sam's club or Costco. I recommend going two 6vdc instead of two 12vdc.

Why the six volt?
There must be a reason other than just a reworking of her wiring?

[Judge]

I went with Duracell 6V Golf Cart batteries. They were reasonably priced and made in the USA. You can get a 10% discount if you order online from Batteries & Bulbs Plus and pick up in store.

https://www.batteriesplus.com/productdetails/sligc115

I installed them back in March and they have worked out great.

They also have a nice selection of the Duracell Group 27 12 volt batteries...

https://www.batteriesplus.com/batter.../bci-group-27m

[GTM41261]

Well I will throw something else out there. Since you like to boondock. Look into Lithium batteries. Yes they are way more money but they would be the last you will need to buy. There are several brands out there but Battle Born seems to be the most popular.

[EA37TS]

Battery primer.

https://www.rvhometown.com/6-volt-vs-12-volt-rv-batteries/

[TurnerFam]

take a battery out and run by Sams Club or Batteries + Bulbs or even a 'golf cart' store and compare the exact size and layout to what they have to offer - Sams and Batteries + both have DURACELL, which are economical and work well.

[Bob Denman]

Any Type 27 AGM Battery.

[sanjaun2]

Originally Posted by ducksface

Why the six volt?
There must be a reason other than just a reworking of her wiring?

Because I know what I'm talking about! 6 volt batteries are better made and last longer in our application. They normally cost a little more but at Sam's and Costco they are very reasonably priced. Costco batteries are made by interstate batteries. Very good for a lead acid battery.

[taylorbob1]

Sams Club or Costco has always worked well for me
Sams has Duracell
Costco has Interstate
Both sell a 12 volt flooded lead acid deep cycle marine/rv battery For under $80

I have the Costco Interstate brand in my rig.

[Pete'sMH]

Whatever you buy be sure to check the manufacture date. It’s usually a small round sticker with the month and year. Try to get them within 6 months. 3 is better.

[DavidEM]

Not much has been said about the type of battery, its construction or its expected life in the above posts. So here goes:

Traditional flooded cell lead acid batteries (the kind with liquid electrolyte inside) need to be specifically built for deep cycle use to get decent life. Deep discharging causes the lead in the plates to be converted to lead sulfate which if left in a discharged state for long, settles out and forms a sludge on the bottom. To combat this, real deep cycle batteries are made with heavier plates that can stand the loss of lead, have more room in the bottom before the sludge builds up and shorts the plates, more headroom above the plates for extra electrolyte and of course filler caps to check and replace lost electrolyte.

Very few 12V batteries are built this way. Your average Walmart, Costco, Batteries Plus, etc are not. Golf cart batteries are built this way because golf cart use is very deep cycle and they will last much longer than your garden variety battery. They are also pretty cheap because the GC market is big and competitive.

There is another type of battery that was mentioned above, the AGM type. These have a glass mat that absorbs the electrolyte and keeps it from being fluid. It won't settle out lead sulfate and seemingly allows the lead sulfate to be more easily converted to lead thus preserving life when used in deep cycle use. They are more expensive but are great for difficult installations because they have no filler caps and don't require checking the electrolyte.

Both of these types of batteries shouldn't be discharged below 50% as that causes lead sulfate to settle out permanently. They also cannot be left in a partially discharged state for long as the same thing occurs.

Carbon foam batteries such as Firefly have a different plate/electrolyte configuration that I don't really understand but they apparently can be discharged deeper and left discharged longer with minimal harm (1,000 cycles at 80% vs 2,000 cycles at 50%).

And then finally there are LiFePO4 batteries such as Battle Borns. They are perfect for deep cycle use as they can be discharged deeply, left in a discharged state for months and can be recharged at high current rates at least double of those above.

So here are some prices for the different types of batteries and are based on approximately 100 nominal amp hours at 12V. It also includes usable amp hours and $/usable amp hour:

GC- $100-125, 60 Ah, $2
AGM- $250, 50 Ah, $5
Firefly- $500, 80 Ah, $6
Lithium- $900, 90 Ah, $10

If you have the room and the weight carrying capacity and you don't mind checking electrolyte and filling with water 3-4 times a year, GC batteries are your best bang for the buck. If you are tight on space and weight then the lithiums might be a good choice, but at a big price differential.

David

[edkjr]

I finally, upgraded to renogy 100ah 12 volt lithium. We replaced the fld batteries twice after changing them out in 4 years. First set where shot and C.W. Wouldn't replace them.
Lot less maintenance with lithium. Only down side initially is to be sure your on board charger, solar charger, and truck charger can be programmed to different charge rates that the litium require.

[Bob Denman]

Question: Are lithium batteries fussy about the temperatures in which they operate?

[Pete'sMH]

Originally Posted by DavidEM

Not much has been said about the type of battery, its construction or its expected life in the above posts. So here goes:

Traditional flooded cell lead acid batteries (the kind with liquid electrolyte inside) need to be specifically built for deep cycle use to get decent life. Deep discharging causes the lead in the plates to be converted to lead sulfate which if left in a discharged state for long, settles out and forms a sludge on the bottom. To combat this, real deep cycle batteries are made with heavier plates that can stand the loss of lead, have more room in the bottom before the sludge builds up and shorts the plates, more headroom above the plates for extra electrolyte and of course filler caps to check and replace lost electrolyte.

Very few 12V batteries are built this way. Your average Walmart, Costco, Batteries Plus, etc are not. Golf cart batteries are built this way because golf cart use is very deep cycle and they will last much longer than your garden variety battery. They are also pretty cheap because the GC market is big and competitive.

There is another type of battery that was mentioned above, the AGM type. These have a glass mat that absorbs the electrolyte and keeps it from being fluid. It won't settle out lead sulfate and seemingly allows the lead sulfate to be more easily converted to lead thus preserving life when used in deep cycle use. They are more expensive but are great for difficult installations because they have no filler caps and don't require checking the electrolyte.

Both of these types of batteries shouldn't be discharged below 50% as that causes lead sulfate to settle out permanently. They also cannot be left in a partially discharged state for long as the same thing occurs.

Carbon foam batteries such as Firefly have a different plate/electrolyte configuration that I don't really understand but they apparently can be discharged deeper and left discharged longer with minimal harm (1,000 cycles at 80% vs 2,000 cycles at 50%).

And then finally there are LiFePO4 batteries such as Battle Borns. They are perfect for deep cycle use as they can be discharged deeply, left in a discharged state for months and can be recharged at high current rates at least double of those above.

So here are some prices for the different types of batteries and are based on approximately 100 nominal amp hours at 12V. It also includes usable amp hours and $/usable amp hour:

GC- $100-125, 60 Ah, $2
AGM- $250, 50 Ah, $5
Firefly- $500, 80 Ah, $6
Lithium- $900, 90 Ah, $10

If you have the room and the weight carrying capacity and you don't mind checking electrolyte and filling with water 3-4 times a year, GC batteries are your best bang for the buck. If you are tight on space and weight then the lithiums might be a good choice, but at a big price differential.

David

Good explanation of the options. But it assumes the buyer needs a maximum performance option. We never boondock and have always found one or two flooded 12V deep cycle batteries to be more than adequate for our needs. If you keep them full and charged they can last 5 years or more. Not bad for $75.

[jtyphoid]

Originally Posted by Bob Denman

Question: Are lithium batteries fussy about the temperatures in which they operate?

The biggest concern is low temp charging. LiFePo4 should not be charged when the battery is below freezing. Batteries from quality manufacturers will have low temp protection to prevent the battery from accepting a charge when it is too cold. Note that it is okay to discharge below freezing, so you don't have to worry about suddenly losing power if it dips below freezing for awhile.

[Bob Denman]

Thanks!
I've seen some mentions of temperature; but your explanation was easily understandable.

[jtyphoid]

Originally Posted by Bob Denman

Thanks!

I've seen some mentions of temperature; but your explanation was easily understandable.

There are also high temp limits, with charging okay up to around 130F and discharging okay up to around 140F, but I don't plan to test those limits any time soon.