Battery Drain - Usual Suspects

[Tonijim]

We have a new-to-us 2010 Four Winds Freedom Elite 31r Just replaced the two 12v coach batteries (probably OEM). The Bosch engine battery was new in 4/13. It will not hold a charge if allowed to sit 4 weeks or so with all systems shut down. It will accept a charge and run fine while on the road or on short stays.

Question - are there usual suspects in battery rundown in a shut down storage situation?

Any thoughts would be appreciated.

Jim

[Calisdad]

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.

[SCVJeff]

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

[Tonijim]

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

Jim

[maillemaker]

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.

[burlmart]

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.

[SCVJeff]

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

[Harvey51]

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.

[leeper]

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!

[NWboondocker]

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.

[cgmartine]

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

[Tonijim]

Thanks to all for the responses. I'll be getting a battery tender to be used in place of my old charger. Any preferences among those of you who use plug in tenders?

Jim

[Butch50]

That is normal in all of the newer vehicles. I had a 2011 Ford F350 and my battery was down in 4 weeks. I talked to the shop and they told me about the longest that it would last without either running it or put a charger on it is 3 weeks. It is all of the parasite loads on it even with the key off.

On my View I keep a battery tender hooked up to the chassis battery all the time. I have the MH plugged in all the time so it is no problem to have the battery tender hooked up and powered from an ac outlet in the camper.

[Hank85713]

I got a 5 amp solar charger from harbor freight for ours. They also have them at the auto stores like oriellys or autozone. Keeps engine battery up to snuff. I place it in front of the sun guard for the windshield, wired in direct. It has a quick disconnect that enables me to take out for travel. works well and does not need ac to te coach unless you want to plug in the house for potential use.

Just make sure that the battery is well charged prior to parking and hooking up.

[pauldub]

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.