Furnace while boondocking.

Jay Coe wrote:
That's a blanket statement that like most generalizations, isn't always accurate. Marine batteries are available in starting, hybrid and true deep cycle. Yes, the marine "deep cycle" batteries at Walmart and Costco are hybrids, but true deep cycle marine batteries are also available.

What exactly is the difference between a "true deep cycle marine battery" and a common true deep cycle battery, like the Trojan previously mentioned? Do they have a picture of a boat on the label or something?

CavemanCharlie wrote:
Another thing you could have done was to have baked some cookies or something in the oven before going to bed. The residual left over heat would have helped to keep your furnaces from kicking in as quickly the first time.

This is a good idea! And I like cookies!

I have (2) Deka Marine Master batteries. DC24. I checked their site and they don't make this one anymore. It's listed as 500 CCA whereas the new model is listed at 480.

My onboard charger charges at 13.6V. I see on their site it says it can boost to 14.4-14.6V. So, maybe they are being undercharged?

I haven't checked the fluid lately. I do have a battery shutoff that I use when it's not being used and for the past 3 winters it has been stored indoors heated. This year will be indoors unheated so I am debating leaving the batteries or pulling them out. I think they still perform pretty good all things considered.

We are on the verge of upgrading in the next year or two if we find the right model so I am not all that much in a rush to put new batteries in for next year.

CavemanCharlie wrote:
Another thing you could have done was to have baked some cookies or something in the oven before going to bed. The residual left over heat would have helped to keep your furnaces from kicking in as quickly the first time.

I'm liking this idea but I may have suffered a stomach ache from trying to eat all of those fresh-baked cookies.:B

Another thing you could have done was to have baked some cookies or something in the oven before going to bed. The residual left over heat would have helped to keep your furnaces from kicking in as quickly the first time.

Another way to "prep" for the night is to use a Mr. Heater Buddy or Big Buddy heater and warm the trailer up nice and toasty before calling it a night. Turn them off when it's nice and warm and set the 'stat for 55-ish for the trailer furnace and go nighty-night.

Does your voltmeter ever go to 14.2+ volts when charging? Good chance those batteries were chronically undercharged by a fixed voltage converter.

Well you guys survived the trip which is what matters. It's even better that you were able to get the furnace running for the second night.

Unless you specifically asked for a true deep cycle battery when purchasing, I can almost guarantee you that the batteries are the standard hybrid 12 batteries that you can get at Walmart, Napa, Autozone,or Camping World. That's not necessarily a bad thing, they just aren't as robust as a true deep cycle.

As you stated, your batteries are old you might want to consider replacing them soon. But since you stated that it is rare to not have power I would replace them with the same basic batteries. If you were going to do more frequent dry camping you might want to consider switching to 6 volt batteries. But in your case I think that would be a bit extreme.

With decent batteries you can typically count on one night of furnace per battery, unless it's extremely cold. So if yours were newer you would have been fine.

Just checking but have you checked the electrolyte level if the battery does have caps on top?

Actually, I am not even sure what's in there because the camper place did it. I will check when I get home to see what it is.