Advice on finding best new coach batteries

[ducksface]

A hint for the op for next time you're in, that battery box:
Put a sheet of that nice white foam some things are packed in or anything else non absorbant and non conductive on top of those batteries.
My battery terminals are uncomfortably close to that metal lid/step.
One bad bump and one broken tie down strap....

(when I was a kid my 1964 El Camino had six raised dimples in the hood from the battery taking a jump and shorting out on the hood.)
I be ferared up since.

[rsgarrett]

I installed two of these:

NPP HR12390W FR 12V 390W, 12V 120Ah,12Volt 120Amp High Rate Rechargeable Sealed Lead Acid AGM UPS Battery

in a battery compartment with exactly the same dimensions as yours (Thor Compass 24TX). $420 for the pair from Amazon, free shipping. It's a tight fit, but can be done with just the right technique. They have been great.

[SueTac]

We put in brand new Interstate batteries... so far great.

[MLP]

Originally Posted by ducksface

Op.
Go to Walmart and buy 24's
You say the 27 won't fit.
The 24 will.
I'll trust you on your judgement of 27's.
Forget the six volt.
No one knows why it was said and they absolutely won't fit and require a rewiring and cut your amps in half for the same space.
AGM is very nice. Buy the 24's because you know they fit.

The lithiums might require equipment you don't have.
Spend the $200, and not the $2,000

Lithium as we know it is on the way out already.

Just. Go. Buy. 24's at Walmart.
It cures your problem.
The $200 is to buy you the time to see which six volt or lithium faction you want to join.

The difference of two 6V vs two 12V is that the 6V gives you much more amp hour capacity. That is why I did it, but I have the crimping tool, lugs, and wire.

[cbach]

Originally Posted by MLP

The difference of two 6V vs two 12V is that the 6V gives you much more amp hour capacity. That is why I did it, but I have the crimping tool, lugs, and wire.

How so? Two 225AH 6 volts provide 225AH's @ 12 volts, while two 120AH 12 volts provide 240AH's. I'm not an electrical engineer, but I did stay at a Holiday Inn Express last night

[MLP]

Originally Posted by cbach

How so? Two 225AH 6 volts provide 225AH's @ 12 volts, while two 120AH 12 volts provide 240AH's. I'm not an electrical engineer, but I did stay at a Holiday Inn Express last night

12V deep cycle batteries are in CCA, cold cranking amps, not in amp hours. CCA devded by 7.25 = AH so 225(CCA)/7.25=31AH The two will give your 62 amp hours.

https://carfromjapan.com/article/car...nvert-formula/

[TLeenhouts]

I use AGM batteries even though they cost more. I tried a Walmart battery and it only lasted a year.
A size 24 battery is 10.8"L X 9.4" high X 6.81" L with 725 CCA
A size 27M(marine) is 12.75" L X 9.9" H X 6.75" W with 650 CCA and a 150 minute reserve.
A size 31 is 12.95" L X 9.5" H X 6.75" wide with 725 CCA and 185 minute reserve.
My tray has three slots built in. The engine battery is a 24 because that's all that will fit that battery tray.
I have a 2004 Windsport 32R class A.

[16ACE27]

Originally Posted by MLP

12V deep cycle batteries are in CCA, cold cranking amps, not in amp hours. CCA devded by 7.25 = AH so 225(CCA)/7.25=31AH The two will give your 62 amp hours.

https://carfromjapan.com/article/car...nvert-formula/

Yeah. that's a neat formula, but he said 12 Volts and AH, not CCA. His example still stands. Switching from (2) 12 volt batteries to (2) 6 Volt batteries of the same dimension may get you a few more AH at 12 VDC, but not "much more".

Those that get much more AHs when switching to 6 volt batteries do so because they get much larger (physically) batteries.

[JoeDS]

First I tried Interstate. After my second set each of which lasted 1 year with very little use I went to walmart and bought 2 of their Max batteries with a 2 year replacement warranty. $87.00 each. I also went with the largest size that would fit which in my case is a 29. More amp hours than a 27. So far so good.

[MLP]

Originally Posted by 16ACE27

Yeah. that's a neat formula, but he said 12 Volts and AH, not CCA. His example still stands. Switching from (2) 12 volt batteries to (2) 6 Volt batteries of the same dimension may get you a few more AH at 12 VDC, but not "much more".

Those that get much more AHs when switching to 6 volt batteries do so because they get much larger (physically) batteries.

That is true, but unless your are using AGM batteries which are in AH and not standard lead acid batteries which are in CCA. I was comparing standard lead acid to lead acid. The size is not much different. A slight height difference with standard lead acid batteries.

[16ACE27]

Originally Posted by MLP

That is true, but unless your are using AGM batteries which are in AH and not standard lead acid batteries which are in CCA. I was comparing standard lead acid to lead acid. The size is not much different. A slight height difference with standard lead acid batteries.

AGM batteries as well as FLA batteries can be rated in both CCA as well as AH. The difference is how they were engineered. You have starting and multifunction deep cycle batteries which have a CCA rating and may also have an AH rating. A true deep cycle battery (either FLA or AGM) will only have an AH rating.

[Pete'sMH]

Originally Posted by SueTac

We put in brand new Interstate batteries... so far great.

Me too. $170 for the pair. Can replace them 2, maybe 3 times for the price of AGM but with proper care they shouldn’t need that. Apparently not everyone’s cup of tea but works for us.

[cbach]

Have been following this and other like threads for awhile, as I've sucked my factory set of 6 volts down to nothing a few times before learning how long I need to run the generator daily, and don't trust them anymore. I'd like to be able to run the fridge and water pump for a few days without worrying about it. Just trying to decide, but leaning towards these...

https://www.amazon.com/Bater%C3%ADa-...9095305&sr=8-5


Don't know if it's worth the extra $50 over some 255AH Flooded Duracell's. Save a little weight with the AGM's, but gain another 30AH with flooded.

[Beau388]

Originally Posted by SueTac

We put in brand new Interstate batteries... so far great.

Interstate batteries are made by Johnson Controls in the same factory as Walmart's brand Everstart. Johnson Controls is the largest manufacturer of automotive batteries in North America. Almost all are made in Mexico.

[JoeDS]

I just lucked out. Went to my walmart store and bought two
Premium EverStart Maxx Marine / RV Battery, Group Size 29DC 120AH @1Amp maintenance free Group 29


2 year replacement warranty . Seems like they were $87 each with exchange

[Jinx]

Thanks for your info. Question, it is almost impossible form me to add water to one of my under step batteries without removing the battery, so when the time comes, would you suggest a gel battery that would do the job. Thor Axis 24.1 2014, solo female owner, only slightly handy.

[lwmcguire]

Lot of discussion regarding batteries so here are my two picks for the money

You gain significant amp hours with 6 volt

If you're keeping a rig and don't like a lot of battery maintenance then AGM or lithium

Battery cables will fail over time due to corrosion as well and post need brushed

Now if you seldom use your battery bank then go cheaper T105-AGM_Reliant_DS_Final.pdf27AGM_Trojan_Data_Sheets.pdf

[Pete'sMH]

Originally Posted by Jinx

Thanks for your info. Question, it is almost impossible form me to add water to one of my under step batteries without removing the battery, so when the time comes, would you suggest a gel battery that would do the job. Thor Axis 24.1 2014, solo female owner, only slightly handy.

Put a flow rite battery watering system on your batteries and you can check/add water in about 30 seconds without even removing the step/cover.

[16ACE27]

Originally Posted by 16ACE27

Yeah. that's a neat formula, but he said 12 Volts and AH, not CCA. His example still stands. Switching from (2) 12 volt batteries to (2) 6 Volt batteries of the same dimension may get you a few more AH at 12 VDC, but not "much more".

Those that get much more AHs when switching to 6 volt batteries do so because they get much larger (physically) batteries.

Originally Posted by lwmcguire

Lot of discussion regarding batteries so here are my two picks for the money

You gain significant amp hours with 6 volt

If you're keeping a rig and don't like a lot of battery maintenance then AGM or lithium

Battery cables will fail over time due to corrosion as well and post need brushed

Now if you seldom use your battery bank then go cheaper Attachment 25917Attachment 25918

Again - you don't; unless you have a significantly larger (physical size) battery.

Lets say, for instance, you have a 12 volt group 29DC battery rated at 120 AH. The same physical size battery built to be a 6 volt battery may be rated at 250 AH.

So take 2 of those 6 volt batteries and wire them in series to give you a 2 battery, 12 volt battery bank - rated at...........250 AH.

Or take 2 of the 12 volt batteries and wire them in parallel to give you a 2 battery 12 volt battery bank - rated at ..........240 AH.

That is not a "significant gain in amp hours" using the 6 volt batteries.

[dkoldman]

Originally Posted by JoeDS

I just lucked out. Went to my walmart store and bought two
Premium EverStart Maxx Marine / RV Battery, Group Size 29DC 120AH @1Amp maintenance free Group 29


2 year replacement warranty . Seems like they were $87 each with exchange

I think you win. I don't see how you go wrong here.

Before I bought my RV I was thinking I needed to get those 6V batteries because the ACE 29.3 I was looking at had Residential Fridge. My RV came with the NAPA 31 with 105ah each so I have total of 210ah now. I check the water in batteries; but I don't like it even though I have easy access, and I don't want a distilled water filler upper or whatever it is called

So if I follow, if I could find two of these, I would have 2 smaller batteries (Group 29 vs 31) with total of 240ah; maintenance free, 2 year warranty for total of $175 What am I missing? Will I be giving up something go from 31 to 29 that I don't know?

Before this thread, I had assume my 1st set of batteries that I buy for this coach was going to be Group 31, AGM and as many amp hours as possible, but most all of the AGMs are like 105 ah