Battery Drain - Usual Suspects

burlmart wrote:


if so, i wonder if a windshield heat reflector has ever been made of a solar panel that plugs into the DC recepticle.

Now that's a really good idea.

burlmart wrote:

SCVJeff wrote:

cgmartine wrote:
Have you considered installing a blade type battery disconnect on the negative post of the engine battery?

the problem with doing that is losing the data that the various CPU's have gathered about driving habits, shift points, etc., not to mention reloading the radio and resetting all of the configs if you have a glass dash. Our DP was good for about 3 weeks before dead battery time, so thats when I started adding Solar

if you plugged solar power into dash DC outlet (often used to charge cell phone), would that charge the chassis batt, or does the recepticle flow both ways?/

if so, i wonder if a windshield heat reflector has ever been made of a solar panel that plugs into the DC recepticle.

Something that small really can't keep up. That's what I read on here back in 2007 and they were right. I had a little 15w panel on the roof and it proved useless. I started with a 100w panel just to maintain the batteries, and Santa jammed another one in my stocking the following years, now 1/2kw.

If you are trying to charge both house and chassis, I think you need to start at 100W

Battery tender arrived and installed today. Thanks to all for your help.

Jim

I installed battery disconnect switches on our engine and house batteries. Never had any problems with the engine "re-learning". Yeah, you lose your radio presets, but those are only good for local stations anyway and we are driving the RV away from "local" :)

Besides, I have a cassette adapter and plug in my ipod with it. I don't even use the presets.

SCVJeff wrote:

cgmartine wrote:
Have you considered installing a blade type battery disconnect on the negative post of the engine battery?

the problem with doing that is losing the data that the various CPU's have gathered about driving habits, shift points, etc., not to mention reloading the radio and resetting all of the configs if you have a glass dash. Our DP was good for about 3 weeks before dead battery time, so thats when I started adding Solar

if you plugged solar power into dash DC outlet (often used to charge cell phone), would that charge the chassis batt, or does the recepticle flow both ways?/

if so, i wonder if a windshield heat reflector has ever been made of a solar panel that plugs into the DC recepticle.

cgmartine wrote:
Have you considered installing a blade type battery disconnect on the negative post of the engine battery?

the problem with doing that is losing the data that the various CPU's have gathered about driving habits, shift points, etc., not to mention reloading the radio and resetting all of the configs if you have a glass dash. Our DP was good for about 3 weeks before dead battery time, so thats when I started adding Solar

It is quite possible to check out the parasitic current draw with just an ordinary multimeter. I just checked my daughter's car. I disconnected one battery cable and connected the meter on the ten amp range between cable and battery terminal. The reconnect must have booted up the computer because there was over half an amp initially. I shorted out the meter with a clip lead to avoid doing that again, then switched it over to the 1 amp range. The current soon dropped to 50 mA - pretty good, I think. It is a low end vehicle with no remote. Had it been higher, I would have opened the fuse box and pulled some fuses to see which was drawing the current (avoiding the computer's fuse because my meter will blow a current range if the range is exceeded). I lost a couple of current ranges on a meter while checking a friend's car - it had a hood light with a loose wire and drew a couple of amps when she leaned on the car and jiggled it.

Say you have a 100 amp-hr battery. It will fall to 50% in 100 hours if the loss is half an amp, 200 hrs for 250 mA. I would look into it seriously if the parasitic drain was 250 mA or more. At that level of current a DC clamp meter is sensitive enough to track down the current in a wire without disconnecting anything.

I leave the motorhome battery disconnected when we aren't using it. I just leave one cable connector slightly loose so I can easily slip it off or on the post. I do tighten it for driving. Parasitic draw is also 50 ma.

pauldub wrote:
I keep a battery tender connected to my chassis battery when I'm home. I'm still running the original battery that was delivered by the factory in 2003.

Same here! Good way to go!

If you're going to have to plug into AC anyway, consider a Trik-L-Start instead. Easy hidden installation. Just plug in your house cord and all your batteries stay charged.

Have you considered installing a blade type battery disconnect on the negative post of the engine battery?