Recommendations for replacement Battery for Unimog 1300 in the USA


It seems that the truck batteries in my Unimog are starting to approach end of life.

Any suggestions for reliable batteries available in the USA that require little or no modifications to the battery box/tray.



Expedition Leader
I am running two Interstate batteries. No idea about fit, but they have been good. Through a bout of stupidity, I killed them and replaced them. When one of the replacements was bad, they gave me two new ones, as the batteries were mounted in series. Very nice support.


Are these for starter or house side? Take a look at your current group size to match.
For start batteries, Interstate is a solid choice, compare CCA and get the highest rated one you can find in a reputable quality battery. Often a deep cycle/start/marine battery will have a better build and be able to better handle extreme conditions and demands of cranking over a diesel.
For house side I’d recommend an AGM(absorbed glass mat), the largest one that’ll fit with the biggest AH(amp hour) rating.
Look for these quality USA made options-
Deka/East Penn-
Batteries Plus carries these as a rebranded Duracell. Also a good place to find a starting batt, and with locations everywhere, easier to warrantee any issues.
Just don’t want to mismatch new with old if you’ve got 2 or more batteries on either side, starting or house, replace at the same time.

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@REF looking for starter side.

In the house, I have 1 year old Victron lithium batteries. I hope that they’ll be good for another 9+ years.

Seem like Interstate is the consensus between you and @DiploStrat.

Several folks in the German Unimog community have gone the Optima Red Top way, as they save weight and space, but from what I hear recently, they have really gone downhill in terms of reliability and longevity.


Well-known member
Duration of the warranty = battery quality.

Check each model because brands will have different warranty for different batteries.

Battery group size can be determined if you measure width - length - height and voltage
Quality AGMs have a good benefit/cost ratio. I have had good results with Lifeline in my camper but will probably eventually replace with Victron LiFePO4 when indicated. Will save ~ 130kg among other things. Will continue to use Pb based AGM for chassis.
Very extremely strongly recommend trickle charger on any/all batteries that are intermittently used. That can be via solar or grid. Greatly increases lifetime and reliability, though less critical with Li types from what I read.


Thanks everyone.
Our Swiss Army Puch came with Austrian made AGMs.

Will have to look where to find some AGMs locally on the east coast.

I am a little reluctant to go lithium on the chassis side. I deliberately chose the Unimog without electronics for best reliability in remote and rugged places and am weary of undermining the concept by lithium starter batteries.

On the house side, I am glad that I splurged for them. Don’t think I could have stayed below 6,000kg wet without them.
It would be EXTREMELY useful if you cared to enlighten us with the size of the batteries. Not measurements but size category (you are familiar with size categories??; my U500NA has 3 size 31 batteries in parallel for 12v plus 2 smaller unknown precise size category motorcycle sized batteries in series for 24v, for example).
Lifeline makes quality AGMs, as mentioned above, in some sizes but not every conceivable size. My camper box has 4 x 4D size AGMs.
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There’s almost always a size rating printed on top. A 2 digit number +/- a letter. Barring that, you’ll have to consult a catalog, Lifetime for example, and try to find a near identical match of the physical dimensions.
It’s a 6TN size group. Which is a tractor size group.
A single 8D would (probably) fit, it’s 11mm wider, 24mm higher, but shorter. Hold downs, your problem to solve.
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