Thanks Paul! I'll let you know when i head back up to Colorado...i'd say i'd be going up for the snow but it just snowed here in Scottsdale yesterday! I agree the sportsmobiles leave some room for improvement and i'm sure even after i'm "finished" building my van I'll still be finding areas to make it better.
Any idea how fast the temperature of the battery drops? Have you come up with any ideas for heating the batteries? I would guess you're thinking of using the espar furnace to pipe heat down to it...
The only things i could think of other than that are heat tape/pad....which would wind up using electricity anyways or some way of piping some of the exhaust to hit the batteries and warm them up. Obviously both those ideas would only really work for while you're driving the van around or at least running the engine.
I would imagine with all the lead in the batteries it would take them a little while to drop in temp but on the other hand i wonder if repeatedly heating and cooling them could damage them.
Originally Posted by jeff@work
We are running 2 4D AGM batteries for the house power. They are hanging under the body between the rocker-panel and the frame on the driver's side. Last winter I added 2" of polyurethane insulation around them, which helps quite a bit, and their daily temperature from day to night only varries about 5 to 10 degrees for a 40 degree air temp variation. Also, charging and using power warms them up a few degrees/day. In the summer they stay cooler, in the winter warmer, and variation over a day is much less than before.
The biggest problem is an extended period of cold (say 3-4 days), where they eventually get down to about the average temperature for a 24hr cycle. When we have the time I intend to build a fairly sealed battery box with vents for cabin heat to circulate around the batteries, OR coolant heat-exchange plates, and run the coolant heater every few days, though this is a less passive solution.
Last week we had to ramp the charging up to about 15.5v just to push charge in, and in the evening when drawing down the output was around 11.8, both of which precluded the use of some of our electronics as the input was out-of-range (most stuff expects around 12.6v).
Last edited by etbadger; 01-23-2007 at 02:09 AM.