Hi Dave,
I have owned this rig since new and it seems to eat batteries quite often, more so now that it is older. It does sit for months between uses. I live in California, so cold is not a major issue. It appears that when I park and plug in the motorhome, which activates the charger and inverter, it cooks the liquid out of my batteries. If I don’t get out there on a regular basis, they cook dry, which destroys the batteries. There are four 27 series RV/marine batteries.
I thought of going to lithium batteries, but from what I read the charger is not compatible. What brand is the best for 12 lead acid batteries? I was thinking once I install the new ones, I would disconnect the batteries from the built-in charger and use individual trickle chargers for each of the four batteries.
I’m also considering which of the trickle chargers to buy. Reading Amazon reviews, even the 4.5+ star ratings have about 5%-7% negative comments that the units quit or didn’t work very well or failed within 12 months.
As you can see by the photo, servicing the batteries and adding water is quite a challenge as they are installed below a steel shelf which does not allow access to the tops of the batteries without pulling them out. Any suggestions would be greatly appreciated. —James, 2005 Fleetwood Revolution LE
Hi James,
I believe your rig originally came with four 6-volt batteries, as Fleetwood was a big fan of the Trojan brand and the high amp hour capacity of the 6-volt batteries. Your rig has a lot of “bells and whistles” and will cycle the batteries more often than a traditional Class A gas model. The 6-volt batteries connected in series and then parallel will also provide more cycles than a traditional 12-volt deep cycle battery. However, since it is a 2005, those batteries are long gone!
Characteristics of FLA deep-cycle batteries
One of the characteristics of flooded lead acid (FLA) deep-cycle batteries is they will gas when being recharged. Most likely your rig came with a larger 2000W inverter that also acts as the battery charger for the unit. This inverter/charger typically is a multi-stage charger providing a high voltage, “bulk” charge. It could be as high as 16 volts to help “boil” the acid and break up sulfation. This is good for conditioning the batteries but does require much more maintenance of filling the cells, which you have experienced.
Looking at your photo, I do have a concern regarding what I believe is a mismatch of battery types. The far left battery is one brand, the two in the middle seem to be the same; however, the far right battery is drastically different. Using different brands and especially adding or replacing one or two batteries at a time will only cause problems with the weakest battery affecting the others.
Adding distilled water
It is critical that distilled water be added to the cells when they get below the vent line and especially below the plates. One of the products that I have been recommending for years is the Flow-Rite Watering System. Pro-Fill Valves replace the traditional caps and tubing connects each valve to a hand pump. Simply insert the fill tube into a gallon of distilled water and squeeze the pump to automatically fill each cell to the recommended level. They run about $10 per cell and you can find them on Amazon here.
What is the best battery
As you have found, there are a ton of very poor batteries available at box stores, discount warehouses, and generic battery distributors. However, there are some really good FLA products available, as well. Winnebago has been using NAPA batteries for several years and have found they are superior in construction and plate material used.
Several RV manufacturers are using batteries from Midwest Battery, which is a wholesale distributor of their own branded battery plus others from U.S. Battery and Odyssey, which I feel is one of the best on the market.
If you do not do a lot of dry camping, lithium batteries are most likely not the best solution. You are correct—you cannot just replace the existing FLA batteries with lithium, especially if you have a multi-stage inverter/charger.
Storage and charging
Instead of pulling the batteries during storage, I would suggest using a Battery Minder. That is a conditioner as well as a charger and does not produce as much gassing, while still helping with desulfation. I have been recommending this product for years and almost everyone that has come back to my seminars loves the product. I will say I have had one reader that states it’s just moon dust and monkey glands and accused me of “Drinking The Kool Aid.” But I have used them for years and I believe they work.
If you have access to 120-volt power during storage, you can use the plug-in version. If not, they also make a solar panel model. Do not confuse it with the Battery Tender, which is a simple trickle charger. You can find the Battery Minder on Amazon here.
It can be permanently mounted to the battery posts or temporarily connected with the alligator clamps. The reviews are almost all 5 star, with a few that complain it is not waterproof, came damaged, or did not revive an already sulfated battery. I, and dozens of attendees at my seminars over the years, have had great success with them.
You might also enjoy this from Dave
Can I just swap my RV’s Interstate batteries with lithium?
Dear Dave,
Can I just remove my RV’s two Interstate 12-volt batteries and install 2 new lithium 100 Ah batteries? —Paul, 2018 Cedar Creek Hathaway 5th wheel
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Dave I have been using the one you recommended for 2 years now. Every time I go out in the winter to start the rig my monitor tells me they are at 12.6 volts. I have had no issues with the charger. If you buy it from Amazon you have an option to purchase an extended warranty. This will insure that it lasts more than a year if defective. I have used their warranty several times for items and have never had an issue. PS, the unit has not boiled out my batteries either. I have only added water once in the last 2 years. But I think I will purchase the battery filler setup. It is easier. Thanks for the info.
All depend on what you can afford. Look into maintenance free batteries like agm battery which does not need water added into it.
My NAPA batteries are from 4/18 and I have a Battery Minder. We dry camp at dog shows regularly and batteries are still fine.
The Battery Tender “Deltran” is not a trickle charger. It charges the battery and then monitors it, coming back on if the charge drops below a certain threshold. A maintainer!
Some people describe trickle charger as battery tender (generic term).
A trickle charger continuously supplies a charge at a low amperage.
I have used one on my motorcycle for over 20 years and also on my TT batteries.
Our larger RV sits upward of six hot months a year unoccupied and 1700 miles from our home. It does have access to AC power and under visual watch. I switched from FLA to AGM batteries for the simple reason that I cannot check on the water level when we are not there. Unlike lithium, AGM batteries are plug & play swaps for FLA batteries. AGM batteries have no longer life than FLA in use, but MUCH longer life than a dry FLA battery.
Thank you, Dave! Good stuff. I especially like the watering system. Safe travels! 🙂
I still see all versions of Trojan Batteries available on line. That’s all I’ve used in my trailer and my family has used farm equipment for years.
The 55lb Trojan 27TMX 12volt that I bought in 2018 is still going strong. I just checked a couple of days ago and could still get one for $200 on line. 105AH
https://www.trojanbattery.com/products/27tmx-12v-flooded-battery
US Battery never held a candle to Trojan brand in my experience. The quality varied too much between matched sets.
I have been using the 1.25 amp Battery Tender Plus 12V Battery Charger and Maintainer for several years it hasn’t failed me yet. It is multi-staged to preform initialization, bulk charge & float/maintenance mode. The tender is attached to my motor-home when it’s in storage and I use it when I travel. Batteries are consistantly 12.6-12.7v. It doesn’t boil my batteries and I only have to add water to the cells maybe once a year.
They have one for 6v also.
in a set up like that, I would be inclined to rig some sort of tray that can be pulled out to expose the whole collection of batteries for service, inspection and ease of rewiring if needed