engine battery drained while connected to shore power

[asmith]

I know little to nothing about my 1999 American Cruiser with Dodge Ram 3500 chassis. The engine/starter battery is being drained while the van is connected to and using shore power correctly. Any ideas? The battery is 3 months old, but has been drained 3 times in this way. Now it is happening after being parked for only 24 hours.
Thanks for your reply!

[Want a B]

In my case shore power does NOT charge the chassis battery. I have a small portable battery conditioner connected to the chassis battery when in storage.

After "draining" your chassis battery 3 times I would suspect the battery is now beyond charging (dead) to full capacity. When a vehicle's ignition is off there is still some electronics on which over a period of time will drain the battery.

[wny-pat]

Your American Cruiser probably has a battery isolator and not a battery separator. The isolator will not let the house power pass thru to the engine battery, but will let it pass the other way so both systems charge while driving. The isolator uses diodes to only allow power to go one direction. A separator uses relays and allows both systems to have charging capability. Blue Sea is probably one of the best for our Class B's. My engine battery has a battery switch so I an turn it off when not using the engine. My Chevy system has a parasitic drain which will discharge my battery, just like yours probably does. I keep then engine battery on a trickle charger/ maintainer until I can afford a Blue Sea Separator system.

[asmith]

Will a trik-l-start device solve this problem?

[wny-pat]

Originally Posted by asmith

Will a trik-l-start device solve this problem?

It should, but not sure it will keep up with you parasitic drain. You would have to trouble shoot it to see what is causing the drain and how bad the drain is! If you don't know your way around auto electrical systems and don't know anyone who does, a good automotive electrical shop would be the best bet. If I were going that route, I'd have them install the Blue Sea replacement! If your going to pay labor, it might as well get it fixed right!

[michaelingp]

Most likely, something is draining your battery. My memory is a little hazy, but I believe our 2000 Roadtrek had a light in a storage compartment that ran off the engine battery. Most of us removed the bulb, but if you left that light on it would drain a battery pretty quickly and you couldn't see it with the compartment closed. This is not a difficult thing to test, but you do need to know your way around the engine compartment and how to use a multi-meter. I agree with others, take it to a shop and explain that something is draining your engine battery. All vehicles have some drain (called parasitic, not sure why), but it usually is not enough to drain a battery in less than a month on most vehicles, although I have heard of as little as two weeks.

I measured this drain on two Honda CR-Vs and they were both less than 20 milliamps, which even over a month shouldn't drain a decent battery. However, with just the dome light on, the draw was 1 amp, which could easily drain a battery in less than a week.

[asmith]

Thanks so much for the detailed responses! Very helpful, and kind of you to take the time to share your knowledge with a newby!
I don't have anyone with background in RVs in my community, so I was thinking I would stop in at a RV service center near a campground. Is that a good idea, or should I take it to a Dodge dealer?

[Jon in AZ]

Originally Posted by asmith

Thanks so much for the detailed responses! Very helpful, and kind of you to take the time to share your knowledge with a newby!
I don't have anyone with background in RVs in my community, so I was thinking I would stop in at a RV service center near a campground. Is that a good idea, or should I take it to a Dodge dealer?

This is a chassis issue so I would start with a good general auto mechanic. It doesn’t have to be a dealer, but it should be near home in case follow-up is needed. I personally prefer an independent mechanic with a small shop, so you work with the same person and they get to know your vehicles. I’m on my second mechanic in 36 years.. The first had the audacity to up and retire on me!

This is a fairly straightforward issue, so it will be a good test of whether a mechanic is a keeper or not.

[michaelingp]

Originally Posted by asmith

Thanks so much for the detailed responses! Very helpful, and kind of you to take the time to share your knowledge with a newby!
I don't have anyone with background in RVs in my community, so I was thinking I would stop in at a RV service center near a campground. Is that a good idea, or should I take it to a Dodge dealer?

The RV service center would be a good bet, but in my experience it's very hard to get an appointment in less than a few weeks. I have nothing against dealers (I take my ProMaster to a RAM dealer all the time), but for this problem, it would be better to go to an independent garage where you can actually talk to the mechanic in person. As Jon says, since this is a relatively easy problem, it's a good "interview" for a new mechanic. Are they respectful, seem to be honest, competent?

[SteveJ]

Originally Posted by wny-pat

Your American Cruiser probably has a battery isolator and not a battery separator. The isolator will not let the house power pass thru to the engine battery, but will let it pass the other way so both systems charge while driving. The isolator uses diodes to only allow power to go one direction. A separator uses relays and allows both systems to have charging capability. Blue Sea is probably one of the best for our Class B's. My engine battery has a battery switch so I an turn it off when not using the engine. My Chevy system has a parasitic drain which will discharge my battery, just like yours probably does. I keep then engine battery on a trickle charger/ maintainer until I can afford a Blue Sea Separator system.

I just bought another Blue Sea separator for our new to us Safari Trek. I had installed one on our RT and liked what it did and how it worked. Model number 7610 for under $80 from Amazon. This particular dual sensing separator features "starter interrupt" which separates the batteries when the engine starter is engaged so there is no sudden inrush of current from the house batteries. Very low current draw and elimination of the problematic(for me) exciter wire on Chevys.

https://www.bluesea.com/products/761...12_24V_DC_120A

Edit to add: I'm thinking this unit will not work with lithium batteries in the mix as it relies on voltages for switching.

Also, one can manually separate the batteries by inserting a switch in the ground wire leading to/from the separator(low current, no relay required).

[RogerC]

When my RV is connected to shore outlet (house 110 volt) it keeps my house battery charged. I plug in battery maintainer to the engine battery by plugging the maintainer into a 110 volt outlet in the camper and plugging the charging end into a cigarette outlet in the dash (which is always live). This keeps both battery fully charged and works great. I also plug in a battery monitor with a led display into the second cigarette outlet on the dash to show the battery charge level of the engine battery.
Both have worked well for me.

[Joe]

Originally Posted by asmith

I know little to nothing about my 1999 American Cruiser with Dodge Ram 3500 chassis. The engine/starter battery is being drained while the van is connected to and using shore power correctly. Any ideas? The battery is 3 months old, but has been drained 3 times in this way. Now it is happening after being parked for only 24 hours.
Thanks for your reply!

Last trip in our 1995 Dodge 3500. We had the same exact problem. Had to get repair man to site. It was the battery isolator.

[Joe]

Last trip in our 1995 Dodge 3500 Xplorer Class B. We experience the exact same problem. After several attempts to figure out. I called a mobile repair person. It was the battery isolator.

[ChicagoTom]

It's most likely your battery separator/idolator. Replace it, or as a test you can simply disconnect it and see if that solves it.