Lots of threads on the subject, but what is the answer (consensus anyway)

[dkoldman]

What is the best AGM battery for a 2019 29VE Sunstar to replace the two factory 65ah Group 24?

Assumptions
1. I will only change batteries (nothing else; so it must work with the Winnebago Progressive Dynamics Converter / Charger, Magnum 1000w inverter, existing alternator system etc. Lithium is presumed NOT and Option.
2. Must fit in existing battery compartment of 29VE Sunstar (if 6 volt golf cart size batteries will fit, it is valid option to go in series for 12 volt.
3. Must be AGM & at least 200AH combined (the more AHs, the more I am interested) I have 1000 watt Inverter and that is all I need, but my primary goal is to attempt to double my capacity.
4. I expect to spend at least $400. (anything over $700 combined is not an option for me)
5. Weight is not a factor as long as it will fit, I have in excess of 2,000+ cargo carrying capacity and don't come close to using it.

Note: My existing Group 24s are working fine. I just hate the corrosion and sulfating of flood acid. I have been adding water, but hate it, So much that I am looking to buy these new batteries before my old batteries go bad; just to get rid of them.

Attached are my current batteries, I took them out and cleaned them up last week. I wish I had taken before picture to show the corrosion and leakage. While batteries were out, I had them checked and both are confirmed good batteries.

Any help is appreciated.

[dkoldman]

Hoping to bounce this post as I don't see as a New Thread?

Input appreciated.

[dkoldman]

Update: While I did not get any input from this site (short all of the other threads which some were very helpful), the below is what I chose to go with after quite a bit of research.

https://www.vmaxtanks.com/SLR125-12V...tery_p_38.html

I placed order today. I expect some drama to ensure they fit. I made 2D cardboard cutoffs the length / width size of these batteries and they may rub against the batteries cables on the back wall.

Credit or kudos goes to Creativepart as on several other threads related to batteries he made a resounding point about getting pure deep cycle batteries I was about to purchase the Duracell Group 31s until I saw that. I additionally think the dedicated pure deep cycle are safer in that you do not have the extra exposed posts that could be touched

So I go from the existing 2 1/2 year old stock floods 130ah combined to the new 250ah Vmax Tanks combined

[DavidM]

I just did something similar on my new Thor Axis short Class A MH. I bought two 100 Ah AGMs made by WindyNation and sold on Amazon for $200 ea. They are dimensionally equivalent to Group 31 batteries and just fit into the under stairs battery compartment.

David

[powercat_ras]

Your batteries are under the step ventilated to the outside air and don't need to be AGM. If you have the height (you will in a Vista), go with two Costco Interstate 6 Volt 200 AH Golf Cart Batteries. They are same size but a little taller. You'll have more capacity for less cost, well under $ 200 for two of them. + to + on one 6 volt battery. - to - on other six volt battery. Use one of the 2 jumpers that were on the former batteries to tie the other 2 posts on the 6 volt batteries to each other. You'll have one jumper left over.

The strap that held down the former batteries won't work it will block accessing the water holes on the golf cart batteries. I just used a couple of scrap pieces of wood to keep the batteries from sliding around. You can use a battery box tie down strap as well if you like. Personally I did not.

[dkoldman]

Originally Posted by DavidM

I just did something similar on my new Thor Axis short Class A MH. I bought two 100 Ah AGMs made by WindyNation and sold on Amazon for $200 ea. They are dimensionally equivalent to Group 31 batteries and just fit into the under stairs battery compartment.

David

I looked at WindyNation and they had good reviews. I ultimately chose the Vmax Tank because they were 125ah; and both times I called them someone answered the phone and talked to me. Answered all of my questions. I bought direct from them. I was about to buy the Duracell's until reading few posts from Creativepart on pure Deep cycles.

I was actually going to wait until this Fall, but I did some more real world testing on my existing NAPA and while they work and are fine, they just can't carry a charge as long as they use too.

[dkoldman]

Originally Posted by powercat_ras

Your batteries are under the step ventilated to the outside air and don't need to be AGM.

Yes but for whatever reason they kept corroding despite the battery sprayed on terminals. They even corroded the mounting brackets!!! Every time I cleaned them, I had battery stains on my concrete. I have added water to them twice in 18 months and that may not have been enough? But a ultimately; I decided I did NOT want flood anymore. My options were AGM or Lithium; and either Lithium is Nutz Crazy cost wise right now or I am just too poor.

If you have the height (you will in a Vista), go with two Costco Interstate 6 Volt 200 AH Golf Cart Batteries. They are same size but a little taller. You'll have more capacity for less cost, well under $ 200 for two of them. + to + on one 6 volt battery. - to - on other six volt battery. Use one of the 2 jumpers that were on the former batteries to tie the other 2 posts on the 6 volt batteries to each other. You'll have one jumper left over.

Again Flood was not an option for me, not to mention I am not a Costco member. I did look at the VMax 6v AGM Golf batteries; but they had less ah than the SLR 125s which is 250ah for both in parallel. Had I bought the golf batteries I would have to watch a video to install them in series. Little confusing when you say + to + on one battery? Are you assuming 4 batteries? If so, I doubt 4 would have fit? Height yes but the total length is 13" I spent $500 for 250ah so I hope that will be enough.

Had I seen this post before buying I would have looked at the vMax tank 6v golf cart batteries harder. I think I ignored because they cost more and they fewer amp hours.

[powercat_ras]

For future reference, this can happen several ways, there's nothing inherently wrong with flooded lead acid batteries that causes corrosion.

- Someone checked battery fluid level and did not get the caps re-seated completely. This is pretty easy to do on the Winnebago OEM NAPA batteries.

- When checking batteries distilled water was added and there was over-fill causing sulfuric acid solution to be spilled.

If any acid was spilled then if it got onto the mounting brackets then it will start to corrode them and rinsing whem with just water won't stop it. You have to neutralize the acid residue with baking soda or a lead acid battery cleaning spray.

When checking and adding water to flooded lead acid batteries you want the battery acid solution level to just touch the plastic at the bottom of the battery cell holes. There's a battery cell filler that costs around $ 10 that makes this easy, or you can just use a re-purposed turkey baster and a flashlight.

[dkoldman]

Originally Posted by powercat_ras

For future reference, this can happen several ways, there's nothing inherently wrong with flooded lead acid batteries that causes corrosion.

- Someone checked battery fluid level and did not get the caps re-seated completely. This is pretty easy to do on the Winnebago OEM NAPA batteries.

I would bet good money that I am guilty of not reseating at least one of the 4 caps properly? They were under the battery cable and very hard to get off

- When checking batteries distilled water was added and there was over-fill causing sulfuric acid solution to be spilled.

I am willing to bet even more money on this one because I am sure I did this. I remember saying oops a few times at that.

If any acid was spilled then if it got onto the mounting brackets then it will start to corrode them and rinsing whem with just water won't stop it. You have to neutralize the acid residue with baking soda or a lead acid battery cleaning spray.

Additionally the rinsing will cause acid to hit and stain the concrete in my otherwise perfectly clean driveway.

When checking and adding water to flooded lead acid batteries you want the battery acid solution level to just touch the plastic at the bottom of the battery cell holes. There's a battery cell filler that costs around $ 10 that makes this easy, or you can just use a re-purposed turkey baster and a flashlight.

A lesson that I learned in life too late

I appreciate the info as I think you have nailed it. But for me, I have enough other stuff on the RV I can worry about and do with ease. I don't need the risk of operator error dealing with sulfuric acid My Vmax solar 125 tanks shipped today. My battery compartment is very clean at the moment; so now is good time to get rid of the Group 24 floods. I want the Group 31 250ah anyway. FWIW I still have a flood for the Chassis. I have never bothered it, because little green light is always green

[BigWoods]

Just saw your post. I would have recommended Vmax batteries. You did well!

[egrochowski]

I have the 2018 model of your rig and I too would like to upgrade to AGMs. Please let me know how well they fit in the current space.
Did you have to adjust the converter/charger?
Thanks.
Gene at [email protected]

[dkoldman]

Originally Posted by BigWoods

Just saw your post. I would have recommended Vmax batteries. You did well!

I am getting excited. UPS delivered one today. The other is due tomorrow. I wonder if they do that on purpose to help the drivers out? Man they are heavy.

It was 13.08vdc out of the box. They are very well packed and neat. A box in a box that was sealed in plastic.
See Picture

Originally Posted by egrochowski

I have the 2018 model of your rig and I too would like to upgrade to AGMs. Please let me know how well they fit in the current space.
Did you have to adjust the converter/charger?
Thanks.
Gene at [email protected]

No, I have the Progressive Dynamics Intelipower 9200 45 amps. I bet you have as well? But it has microprocessor controlled Charge Wizard that does it all for you. VMax confirmed for me and they got excited with confidence. It is amazing how many people insist on buying their own various flavors of chargers, maintainer and floats to put on their batteries separately with extension cord?

As far as fit goes, there will be some drama. I made two cardboard cutouts the 2D Length & Width of the VMax group 31s, and it is close enough that 1/16 of an inch can make a difference. The key will be if I can hold a 75 pound block at a angle to twist and turn do they fit naturally? I think I may have to remove the Chassis battery to put the two Group 31s in?

[dkoldman]

I was able to get both Group 31s to fit. They are really heavy I did not have to remove the chassis battery, but I did take out the mounting brackets to push it further to the right. I was able to put all of my mounting brackets back in their original place; so those batteries are not moving.

Both batteries were 13vdc out of the box. I am allowing the Converter's Charge Wizard to do it's thing for next 24 hours; and then I will start to test to see how much additional time I have.

My feedback from the process.
1. The positive posts were close to the back wall and fuse blocks so I had to use crescent wrench, the negative worked fine with 1/2 socket.
2. I think I prefer the post versus the screws that screws inside the battery. It was a PITA to to get the positive lugs on the screw and then try to force it into the screw holes.

[Elkman]

I like to get Interstate as if there is a problem I can exchange it locally. Hard to beat Costco prices. With AGM you are not getting a true deep cycle battery with the deeper discharge capabilities they provide or the longer life in terms of charge cycles. This is why you will not see the AGM type batteries in use on golf carts or fork lifts.

Good idea to add a battery temp sensor for the solar charge controller to keep it from overheating the batteries when charging. The sensor clamps onto the battery post and runs to the charge controller.

[dkoldman]

Originally Posted by Elkman

I like to get Interstate as if there is a problem I can exchange it locally. Hard to beat Costco prices. With AGM you are not getting a true deep cycle battery with the deeper discharge capabilities they provide or the longer life in terms of charge cycles. This is why you will not see the AGM type batteries in use on golf carts or fork lifts.

Good idea to add a battery temp sensor for the solar charge controller to keep it from overheating the batteries when charging. The sensor clamps onto the battery post and runs to the charge controller.

These are true AGM deep cycle batteries. https://www.amazon.com/gp/product/B0...TSR61H8N&psc=1

If I wanted 6v Golf Cart AGM with true deep cycle I could have bought https://www.vmaxtanks.com/V6-225-6Vo...ery-_p_48.html but it actually has fewer amp hours than the the SLR 125s I purchased.

The Group 31s at Sams is a Dual Purpose Marine / RV AGM battery and you are correct it is NOT a PURE Deep Cycle. I don't shop at Sam's nor Costco, but I would have gone there if they had anything like the Solar batteries I bought. the SLR 125s can last 8 years and have more than twice the cycles of regular batteries.

FWIW, in my earlier thread my PRIMARY intent was to get a way from Flood Acid. My flood acids work perfectly well. I just did NOT want to manage water, deal with desulfication corrosion, spillage on my driveway etc. My OEM stock floods are listed on ebay if someone wishes to make offer and pickup. I wouldn't buy an ESP for piece of mind, but I just paid $500 for SLR 125 ah pure AGM deep cycles for piece of mind.