Dear Dave,
I received a battery watering system for my RV’s four 6-volt FLA [flooded lead acid] batteries. As I live in Colorado, I am concerned about the system freezing during winter storage in an unheated carport. (I keep them charged to prevent freezing.) When in use during camping season, does the electrolyte circulate through the batteries and avoid freezing, as a charged battery does? How do I keep the watering system from freezing? Thank you. —Mark, 2003 Fleetwood Revolution 40C
Dear Mark,
From the photo you provided, I see you currently have the quick disconnect fill cap system, but you did not indicate the make of the new watering system. I believe you are referring to an auto fill system like the Trojan HydroLink™ or Flow-Rite, both of which replace the caps with a check valve and have a tube connected to each and a supply line. You can find the Flow-Rite system on Amazon here.
When electrolyte freezes
According to most battery manufacturers, the electrolyte in a battery will not freeze until -90 degrees if the battery is charged to 100% State Of Charge (SOC), but it will freeze at 5 degrees if it is at 50% SOC. So, keeping your batteries fully charged will keep them from freezing and will also keep the valves in your watering system from freezing.
What you would need to be careful of is the distilled water that would stay in the short tubes between the valves and the supply tube with the check valve that you would insert into a jug of distilled water.
It is possible the heat generated from the RV battery would keep the tubes from freezing. However, I don’t think I would chance it, so I would disconnect the rubber tubes from the top ports of each set of valves as well as the supply hose. The plastic pipe on top of each valve will be OK as they are open at each end and water should drain out.
Another option would be to place a 60-watt bulb on top of the batteries, which will supply enough heat to keep them from freezing. We have been doing this in the water center for units used at the Winter Dance Party at the Surf Ballroom in Clear Lake, Iowa, for years.
One last thing: Make sure you clean the posts, as I see quite a bit of corrosion on several connections.
You might also enjoy this from Dave
What is best brand of FLA batteries for RV? How do I add water to them in a tight compartment?
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. …
Read the rest of James’ question and Dave’s answer.
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Yet another reason for my switch to AGM batteries. If you can’t or aren’t fanatic about water levels in FLA batteries, just keep AGM batteries properly charged.
We store a TT 1700 miles from our home for roughly 6 months. AGM might cost a little more upfront but due to the water issue have a longer life thus saving us money.
If you take advice about “60” watt bulbs it’s about incandescent lamps that produce heat. They haven’t by law been sold for over 2 years. I know I haven’t got one in my house. Leds don’t produce any / much heat
You can still get a 60 watt grow bulb or agricultural heat bulb. Or my Dad still has a house full of them, won’t switch to LED!
Thank you, Dave! Very helpful! Have a great day and safe travels! 🙂