Buying Guide
6 Best Group 31 RV Battery in 2026: A Practical RV Guide
Six Group 31 RV batteries compared on chemistry, usable energy, cranking amps and price, so you can pick the right house or dual purpose bank.
By Hardcastle's RV Editors
10 min read6 products evaluated
Group 31 is a case size, not a promise. The same 13 inch box holds a lithium house battery, a dual purpose AGM that can also crank an engine, and a plain starting battery that will die in a few deep discharges. We sorted six listings by what they actually do, then compared stated cycles, cold amps, case dimensions and price, so you can match the label on the shelf to the job in your rig.
Hardcastle’s RV field notes
The Rig Fit Check
A quick way to connect the shortlist to the space, workload and ownership details that matter after the box arrives.
- Start with the job
- Litime 12V 100Ah Group 31 LiFePO4 Battery for RV leads this shortlist for RV house banks. Use that fit as a reference point, then compare the alternatives against your own space and workload.
- Specs that separate the picks
- The first details to compare are 12V 100Ah LiFePO4, 110Ah, 825CCA, 105Ah, 825CCA, 1072MCA. Confirm the exact model and included components before ordering.
- Trade-off to plan for
- Cannot start an engine, no cranking amps listed
The Practical Shortlist
A road-tested-thinking look at 6 options, organized around the job each one suits best.
Best Overall
Litime 12V 100Ah Group 31 LiFePO4 Battery for RV
RV house banks
Our take Check price for Litime 12V 100Ah Group 31 LiFePO4 Battery for RV (opens in a new tab)
Runner-Up
Weize BCI Group 31M Dual Purpose AGM Battery
Dual purpose start and house
Our take Check price for Weize BCI Group 31M Dual Purpose AGM Battery (opens in a new tab)
Best for Tight Fit
Group 31M Marine Battery Dual Purpose Marxon 12V 105Ah 1072MCA 825CCA
Tight battery trays
Our take Check price for Group 31M Marine Battery Dual Purpose Marxon 12V 105Ah 1072MCA 825CCA (opens in a new tab)
Best for Deep Cycling
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA 1155CA Group 31 AGM
Cranking plus cycling
Our take Check price for Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA 1155CA Group 31 AGM (opens in a new tab)
Best for Marine Style
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA Group 31M AGM
31M case required
Our take Check price for Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA Group 31M AGM (opens in a new tab)
Best Budget
Mighty Max Battery MM-G31 Start and Stop Car BCI Group 31 12V 100AH
Starting duty only
Our take Check price for Mighty Max Battery MM-G31 Start and Stop Car BCI Group 31 12V 100AH (opens in a new tab)
Why Each Pick Made the Cut
Best Overall1 of 6
Litime 12V 100Ah Group 31 LiFePO4 Battery for RV on Amazon (opens in a new tab)
Litime 12V 100Ah Group 31 LiFePO4 Battery for RV makes the shortlist because 4000+ cycles at full depth means decades of weekend use.
Best for
- RV house banks
Why it made the shortlist
This model is aimed at RV house banks. The documented setup centers on 12V 100Ah LiFePO4, 4000+ cycles at 100% DOD, charges only above 32F.
The most useful documented advantage is 4000+ cycles at full depth means decades of weekend use. Against the other 5 picks, the useful comparison starts with 12V 100Ah LiFePO4 and 4000+ cycles at 100% DOD. Those details show whether its configuration suits the job better than a neighboring recommendation.
The main limitation to plan around is cannot start an engine, no cranking amps listed. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 12V 100Ah LiFePO4
- 4000+ cycles at 100% DOD
- Charges only above 32F
Pros
- 4000+ cycles at full depth means decades of weekend use
- Nearly all of the 100Ah is usable energy
- Expands to 4P4S for a bigger bank later
Cons
- Cannot start an engine, no cranking amps listed
- Charging stops below 32F without extra heating
Runner-Up2 of 6
Weize BCI Group 31M Dual Purpose AGM Battery on Amazon (opens in a new tab)
The strongest case for Weize BCI Group 31M Dual Purpose AGM Battery is starts engines and runs house loads in one box.
Best for
- Dual purpose start and house
Why it made the shortlist
For Dual purpose start and house, this is one of the more relevant configurations in the shortlist. The documented setup centers on 110Ah, 825CCA, 240 minute reserve capacity, charge at 14.4V constant.
Its case starts with starts engines and runs house loads in one box. Its 110Ah, 825CCA specification sits at the upper end of the comparable range in this 5-product comparison. Treat the battery platform and included charger as part of the fit, not just the headline number.
The trade-off worth checking first is no cycle life figure is listed. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 110Ah, 825CCA
- 240 minute reserve capacity
- Charge at 14.4V constant
Pros
- Starts engines and runs house loads in one box
- Sealed AGM, no watering and no spills
Cons
- No cycle life figure is listed
- Dual purpose plates wear faster under deep discharge
Best for Tight Fit3 of 6
Group 31M Marine Battery Dual Purpose Marxon 12V 105Ah 1072MCA 825CCA on Amazon (opens in a new tab)
Group 31M Marine Battery Dual Purpose Marxon 12V 105Ah 1072MCA 825CCA is the better fit when tight battery trays.
Best for
- Tight battery trays
Why it made the shortlist
The intended use case is Tight battery trays. The documented setup centers on 105Ah, 825CCA, 1072MCA, 12.99 x 6.61 x 8.35 in, 200 minute reserve capacity.
What separates it on paper is exact dimensions and terminal side are published. Its 105Ah, 825CCA, 1072MCA specification sits at between the lower and upper ends of the comparable range in this 5-product comparison. Treat the battery platform and included charger as part of the fit, not just the headline number.
Before committing, account for costs $10.00 more than the Weize for less capacity. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 105Ah, 825CCA, 1072MCA
- 12.99 x 6.61 x 8.35 in
- 200 minute reserve capacity
Pros
- Exact dimensions and terminal side are published
- 825CCA starting power with 105Ah of capacity
- Sealed lead calcium build needs no watering
Cons
- Costs $10.00 more than the Weize for less capacity
- Hardware is limited to screws, no terminal accessories
Best for Deep Cycling4 of 6
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA 1155CA Group 31 AGM on Amazon (opens in a new tab)
Choose Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA 1155CA Group 31 AGM for 925CCA beats every other dual purpose pick here.
Best for
- Cranking plus cycling
Why it made the shortlist
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA 1155CA Group 31 AGM is positioned for Cranking plus cycling. The documented setup centers on 100Ah, 925CCA, 1155CA, pure lead AGM, 400 deep cycles claimed.
The feature doing most of the work here is 925CCA beats every other dual purpose pick here. Its 100Ah, 925CCA, 1155CA specification sits at the lower end of the comparable range in this 5-product comparison. Treat the battery platform and included charger as part of the fit, not just the headline number.
The practical constraint here is costs $139.36 more than the lithium LiTime. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 100Ah, 925CCA, 1155CA
- Pure lead AGM
- 400 deep cycles claimed
Pros
- 925CCA beats every other dual purpose pick here
- Pure lead plates claim 2X the life of alloy AGM
- Sealed design suits cab and compartment mounting
Cons
- Costs $139.36 more than the lithium LiTime
- Only 400 cycles, far below lithium
Best for Marine Style5 of 6
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA Group 31M AGM on Amazon (opens in a new tab)
Interstate Batteries Marine/RV Battery 12V 100Ah 925CCA Group 31M AGM makes the shortlist because 925CCA gives strong cranking power for hard engine starts.
Best for
- 31M case required
Why it made the shortlist
This model is aimed at 31M case required. The documented setup centers on 100Ah, 925CCA, group 31M, pure lead AGM, marine and RV dual purpose.
The most useful documented advantage is 925CCA gives strong cranking power for hard engine starts. Its 100Ah, 925CCA specification sits at the lower end of the comparable range in this 5-product comparison. Treat the battery platform and included charger as part of the fit, not just the headline number.
The main limitation to plan around is costs $35.00 more than the identical 31-AGM7. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 100Ah, 925CCA
- Group 31M, pure lead AGM
- Marine and RV dual purpose
Pros
- 925CCA gives strong cranking power for hard engine starts
- Pure lead plates for extended service life
- Marine rated build tolerates vibration from rough roads
Cons
- Costs $35.00 more than the identical 31-AGM7
Best Budget6 of 6
Mighty Max Battery MM-G31 Start and Stop Car BCI Group 31 12V 100AH on Amazon (opens in a new tab)
The strongest case for Mighty Max Battery MM-G31 Start and Stop Car BCI Group 31 12V 100AH is 900CCA starting power in a sealed case.
Best for
- Starting duty only
Why it made the shortlist
For Starting duty only, this is one of the more relevant configurations in the shortlist. The documented setup centers on 100Ah, 900CCA, 140 minute reserve capacity, sealed AGM, spill proof.
Its case starts with 900CCA starting power in a sealed case. Its 100Ah, 900CCA specification sits at the lower end of the comparable range in this 5-product comparison. Treat the battery platform and included charger as part of the fit, not just the headline number.
The trade-off worth checking first is shortest reserve capacity of the group. Confirm whether the battery and charger are included with the exact package. Check platform compatibility and published runtime against the area or workload you need to cover.
Key dimensions & specs
- 100Ah, 900CCA
- 140 minute reserve capacity
- Sealed AGM, spill proof
Pros
- 900CCA starting power in a sealed case
- Spill proof design mounts in cab or bay
Cons
- Shortest reserve capacity of the group
How We Built This Shortlist
Each pick was assessed across 4 criteria weighted for real-world use.
- Chemistry and duty
- We separated lithium house batteries, dual purpose AGM and starting batteries, since each fails differently under daily cycling.
- Usable energy
- We compared stated Ah and voltage and noted the depth of discharge a normal owner can actually use.
- Case and cranking data
- We checked posted dimensions, terminal layout, cold cranking amps and reserve capacity where the listing gives them.
- Cost over life
- We weighed price against stated cycle counts, treating unlisted cycle life as unknown rather than assuming it.
What Matters Before You Choose a Group 31 RV Battery
Key buying criteria so you get the right fit the first time.
Chemistry decides the job
Group 31 describes only the case, so the same size can hold a lithium deep cycle battery, a dual purpose AGM or a starting battery. A starting battery spends its life delivering short bursts and loses capacity quickly when it runs a fridge overnight. Check the title and bullets for the words deep cycle, dual purpose or starting before anything else.
Usable energy, not rated Ah
Ah is the capacity on paper, and lead acid chemistries should normally be cycled to about 50% to protect the plates. A 100Ah AGM therefore gives roughly 50Ah of everyday use, while a 100Ah LiFePO4 can deliver close to all of its 1,280Wh. Look for a stated depth of discharge next to any cycle count.
Cycle life at a stated depth
A cycle number means little without the depth of discharge it was measured at. Interstate states 400 deep cycles for the 31-AGM7 and LiTime states 4000+ cycles at 100% DOD, which are very different promises. Divide price by cycles and treat any listing with no cycle figure as unknown.
Cranking amps versus reserve
Cold cranking amps (CCA) show how hard a battery can start an engine, while reserve capacity shows how many minutes it can supply 25 amps. You need CCA only if the battery starts something, and reserve capacity matters for house loads. Compare them on the listing, such as 825CCA with 240 minutes on the Weize.
Case fit and cold limits
A true Group 31 case is about 13 x 6.6 x 8.4 inches, and the 31M variant can place terminals differently. A tray that holds one brand may not fit another by a quarter inch. Check posted dimensions and terminal side, and for lithium confirm the charging cutoff, which is 32F on the LiTime.
Match a Group 31 RV Battery to Your RV
By Job in the Rig
| Your situation | Recommended pick | Why |
|---|---|---|
| Boondocking house bank, no engine starting | LiTime 100Ah Lithium | Stated 4000+ cycles and near full usable capacity beat any AGM here. |
| One battery to start a generator and run lights | Weize 110Ah AGM | 825CCA and 110Ah in one sealed box for $239.99. |
| Tow vehicle or generator starting only | Mighty Max MM-G31 | 900CCA at $229.99 with no deep cycle features you would pay for. |
| Fridge or APU duty with occasional cranking | Interstate 31-AGM7 | Pure lead plates with a stated 400 deep cycle rating. |
Scroll sideways to see every column.
By Budget
| Budget | Recommended pick |
|---|---|
| $220 to $240 | Mighty Max MM-G31 or Weize 110Ah AGM |
| $240 to $290 | Marxon 105Ah AGM or LiTime 100Ah Lithium |
| $420 to $460 | Interstate 31-AGM7 or Interstate 31M AGM |
Lithium vs AGM
- Lithium (LiFePO4)
- The LiTime 100Ah Lithium can be discharged almost fully, lists 4000+ cycles and is far lighter, but it cannot crank an engine and charges only above 32F.
- AGM (lead)
- The Weize 110Ah AGM, Marxon 105Ah AGM, Interstate 31-AGM7, Interstate 31M AGM and Mighty Max MM-G31 can crank engines and charge in cold weather, but you should plan on using about half the rated Ah to protect plate life.
Default to lithium for a pure house bank, and pick an AGM only when the same battery has to start something.
By Budget
| Best pick | Recommended pick |
|---|---|
| Under $240 | Mighty Max MM-G31 |
| $240 to $290 | LiTime 100Ah Lithium |
| $290 to $430 | Interstate 31-AGM7 |
| Above $430 | Interstate 31M AGM |
For Winter Camping Specifically
- Look for
- The charging cutoff temperature on the listing, since lithium cells can be damaged by charging when frozen.
- In this comparison
- The LiTime 100Ah Lithium stops charging below 32F and discharging below -4F, so below freezing the Weize 110Ah AGM is the safer charge acceptor.
When to Spend More
- Spend more if
- Spend more on the LiTime 100Ah Lithium ($285.59) if you cycle the battery nightly, because its stated 4000+ cycles dwarf the 400 cycles Interstate lists for the 31-AGM7.
- Save if
- Save with the Mighty Max MM-G31 ($229.99) if the battery only starts a tow vehicle or generator and never runs a fridge overnight.
Before You Bring One Home
Can a Group 31 lithium battery replace my AGM house battery?
Usually yes, because the 100Ah LiTime fits the same case size. Confirm your converter or charger has a lithium profile or can hold 14.4V without a desulfation mode.
Is a dual purpose battery good for a house bank?
It works as a small house bank when it also has to start an engine, like the Weize 110Ah AGM. A dedicated deep cycle or lithium battery will outlast it under nightly cycling.
Does Group 31M differ from Group 31?
The 31M marine variant is the same size family but can use different post styles and plate construction. Compare the posted dimensions and terminal side before ordering.
How cold is too cold for the LiTime?
LiTime lists charging stopping below 32F and discharging stopping below -4F. If you camp below freezing, plan on a warm compartment or an AGM.
Bottom Line
Best overall: Litime 12V 100Ah Group 31 LiFePO4 Battery for RV — best overall pick in this roundup. See the full verdicts above for every pick, with pros, cons and who each one suits.
Browse all group 31 rv battery on Amazon — Prime-eligible options with current pricing.