[coralcruze]

Originally Posted by Bill

Unless you are also running the furnace, which consumes a lot of power if the temps are even moderately cold.

If the battery in question has a cca rating, it is most likely a pure motor-start battery, and not a deep cycle battery or a combination (aka marine) battery. Among the three, a motor start battery is the worst choice. Walmart sometimes has true deep cycle batteries in stock, but my experience says not often

Some WalMarts (not necessarily all) test your battery with a simple handheld voltmeter - in other words, no load. This tells you pretty much nothing, but they will still tell you your battery is bad, and you should buy a new one. I even caught a Ford dealer doing this to my F-150 once. A true battery tester is a sheet metal enclosure maybe 6 inches on a side, with a carry handle, vent holes, and heavy cables and clips.

I have had decent luck with WalMart batteries - but you need to know what is happening.

Bill

I believe I took a picture of the battery last week. I think it states deep cycle and 80 ah. OI will post the picture as soon as I find it.