Monday, September 25, 2023


Ask Dave: What is the best battery for a diesel pusher?

Dear Dave,
Our house batteries are having problems and we want to upgrade. We have a 2015 Winnebago Tour. Could you recommend a replacement battery? Thanks for your help. —Gerald

Dear Gerald,
According to the Winnebago Archive on their website, your 2015 Tour originally came with six 12-volt deep cycle batteries that were absorbed glass mat (AGM). This means they were sealed and maintenance-free. Typically, these batteries had 100-amp-hours of capacity so that would mean you had 600-amp-hours. However, your AGM batteries should only be drained to 50 percent, which means 300 useable amp hours. It also had a 2,800-watt pure sine wave inverter that would provide a superior maintenance charge for them. So I’m surprised to hear that you are having problems with them. They typically used NAPA brand batteries as they have superior materials and connectivity. However, if the unit was stored without power, the batteries could have gone bad.

Dry camping depends on the battery

The best battery for a diesel pusher depends on how often you dry camp and what battery capacity or amp hours you need. Since you have a very large French door residential refrigerator, you will need all six batteries working in good order to provide 120-volt power through the inverter if you are doing any dry camping. This may be another reason the batteries have gone bad due to the “cycling” they have gone through. And doing the math, it has been more than seven years since those batteries were new.


The best battery for a diesel pusher

Most RV manufacturers that specify the residential refrigerator use 6-volt deep cycle batteries connected parallel in series. This means two batteries connect positive to negative which provides a 12-volt “bank.” Then those batteries are connected to two or four other parallel, which keeps the voltage at 12 volts but then doubles the amp hours. 6-volt batteries can be purchased in larger amp-hour ratings than 12 volt and typically have more cycle life. If you went with six 6-volt batteries that had 200-amp-hour capacity, you would have 600-amp-hours, and the same 300-amp-hours available at 50% percent. However, it would cost you more than going with the 12 volt but would last longer in cycles.

Are lithium batteries the best battery for a diesel pusher?

Another option is lithium, which you can drain to almost 100 percent. This means that three 100-amp-hour lithium batteries would provide about the same power and you could even go more. But the price is twice as much. You would need to check out the charging power of your inverter since the lithium typically needs 14.6 volts of constant charge. Some inverters have a multistage charging system that goes higher than that initially to break up sulfation. This would ruin your lithium batteries. Check to see if there is a setting on the inverter for lithium. Plus, if you have a standard 2-stage charger, it will only provide 13.6 volts until the battery reaches 12.6 volts, and then drop to 13.2 volts for maintenance. This will not fully charge your lithium batteries, so you are only getting about 75 percent capacity of what you paid much more for.

The quality of the battery matters

Whatever you choose, make sure you research and get a good battery, not something from a discount warehouse or home improvement store. If you decide to stay with AGM batteries, I would suggest Lifeline as they are one of the premier battery manufacturers and the batteries will last.

If you do decide to go lithium, I would suggest contacting Lifeline or a couple of other companies that we have researched such as Go Power! and Expion360. You want to make sure the battery is not only good quality but also has a battery management system (BMS) incorporated into it. This helps protect the battery during cold weather charging, and from other issues.

If you do not dry camp much, I would suggest going with six 12-volt AGM batteries that you do not have to worry about the fluid level or sulfation… or at least not as much.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


  1. The person asking the question said he wanted to upgrade his batteries. His unit according to Winnebago and Dave came with AGM batteries. Lithium batteries are the only way to accomplish an “upgrade”. Everything else would be staying with what he has or downgrading.

  2. All – AGM or even Lead acid are the best choice, why. Currently, the USA to my knowledge has NO rules in place to recycle lithium batteries, in many places they might even be tossed into landfill, BAD, BAD. I know CA, OR, WA have recycling plans in place for batteries, as I worked in Hazardous place, and we got batteries all the time. LA recycling has been in place for long time. Lithium is just a bad choice, expensive, and hard to recycle.

      • Several years ago I wanted to change over my flooded batteries to lithium and found several places to purchase them locally. However, when I asked about recycling them no one knew where I could get this done. Currently In my little corner of the world there is still no one “certified” to recycle large lithium batteries such as those mentioned in this article, the key word is CERTIFIED. I can find plenty of recyclers for small electronic batteries, however, none for the larger ones unless I drive about 1 1/2 hours one way. Spent lithium batteries pose a huge fire risk if not stored and disposed of properly and not to mention the environmental hazards associated with them. A year ago I had a electronic device with a lithium that became so hot it scorched a table top. Luckily I was home to smell it and got it out of the house before a fire started. The battery was swelled up so big I needed to pry it out of the device. For now, no thank you to lithium batteries.

  3. If you go lithium I would suggest Battle Born brand batteries as there made in Reno Nevada and not China that has killed over 800,000 Americans with the ****** Flu.

      • If you have a choice buy American. We have become dependent on the CCR for everything. If you have a choice buy local. Big Box has eliminated local dealers.

      • Answer this (Leonard); at the beginning of this virus pandemic , why did the CCP leader NOT allow anyone living in wuhan to travel throughout other areas in china, but allowed them to travel everywhere else on this planet? Tend to believe this was an intentional act to spread this virus around the world. Not sure we will ever have definitive proof.

    • Keep your satire for the rally. I bet the phone you’re typing your comment on or the computer you’re using daily is made by the same people.
      If you’re going to drop the hot ones you better be all in and stop buying everything from China.
      You remember about 10 years ago when all those people in Seattle protested the oil drilling platform? They were protesting from the water in their kyacks made from petroleum products? They got to the protest in the gas burning cars… That’s you. Go you.

      • Hope I don’t get censored for being a little off topic but we gave up our choices when we gave up manufacturing. As far as replacement batteries- I just buy lead acid ones. A set have lasted six years in my Winnebago. That includes the original Napa ones, so at about $100.00 each I think they are a bargain. I also have a budget.


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