Deep Cycle Battery

[Natetheskate]

I was looking at the Northern Tool catalog for deep cycle batteries that would fit my rig, and noticed two with the Interstate brand:

Group 31 98 amp hours, 27 lbs $179.99
or:
a 90 AH, 50lbs, $199.99

Does anyone out there know the difference between the two? I always thought the heavier the battery, the more power in it, but this shows the lighter battery has slightly more AH.

 

[CharlesinGA]

The more expensive battery is a Group size 27 battery and is a maintenance free (not AGM but just about as good) while the cheaper battery is a standard wet battery with recessed caps. I think the 27 lbs is a typo, The weight is NOT given on the Interstate web site for the SRM-31 battery, nor is it given for the 27M-EFB.

I think Northern invented weights, as Interstate does not publish them apparently.

I would check the dimensions of your battery box and go with the group 27 battery if it will fit. Its a better battery.

27M-EFB

• Length 12 3/4 inches
• Width 6 3/4 inches
• Height 9 1/2 inches

SRM-31

• Length 13 inches
• Width 6 3/4 inches
• Height 9 5/8 inches

Charles

 

[John From Detroit]

I was looking at the Northern Tool catalog for deep cycle batteries that would fit my rig, and noticed two with the Interstate brand:

Group 31 98 amp hours, 27 lbs $179.99
or:
a 90 AH, 50lbs, $199.99

Does anyone out there know the difference between the two? I always thought the heavier the battery, the more power in it, but this shows the lighter battery has slightly more AH.

Not a lot of difference other than the battery type. I'm not sold on AGM.
But many here are.
But why not go with a pair of GC-2 Flooded wet if you can hold them around 220 amp horus for about the cost of the 90 AH.. And what's more those "GOLF CAR" (GC) class well you can use a greater portion of it so you end up with over That's over twice the power storage and around 4 times the usable power (Though an inverter may cut out earlier) for about the price of the 90

 

[Contributor]

Here are the specs for the SRM-31 from another web site.

 

[Gary RV_Wizard]

The physics of the chemical reaction in a lead-acid battery don't change with the size or brand. It takes more lead to store or produce more amp-hours. So that 27 lb weight has to be an error. A lead-acid battery would have to be near 60 lbs to contain enough lead to deliver 90AH.

 

[Ray-IN]

Might I suggest, instead of buying an advertised "deep-cycle" battery that also says marine use and lists cranking amps., that you consider Renogy true deep-cycle batteries for solar storage use and RV use.
Right now Renogy 12V, 100A batteries are $189.99, either on the Renogy website or Amazon with free shipping and no core charge.
BTW, they weigh 65# ea.

 

[Natetheskate]

This Renology battery, which I believe is an AGM, can it be used as a "drop-in" battery, or does it need a special charger?

 

[John From Detroit]

This Renology battery, which I believe is an AGM, can it be used as a "drop-in" battery, or does it need a special charger?

If it an AGM the standard Lead Acid settings are close enough.. If you have something like a progressive Dynamics Wizard or IOTA IQ4 they are absolutly close enough.. But even with a WFCO they are very close. like 0.1 volt or less.

 

[Tulecreeper]

This Renology battery, which I believe is an AGM, can it be used as a "drop-in" battery, or does it need a special charger?

Basically, an AGM battery is the same as a flooded lead acid battery, it's just sealed. A regular LA charger will work just fine.

 

[Lou Schneider]

Basically, an AGM battery is the same as a flooded lead acid battery, it's just sealed. A regular LA charger will work just fine.

Although you do have to avoid overcharging or equalizing charges with AGM. Since it's sealed and the electrolyte is encapsulated in the glass mat there's no way to replace it if overcharging makes part of the electrolyte boil away.