Engine Battery Drain

harmstrong17 · 04-24-2013, 06:50 PM

Have a 2005 Itasca Horizon 40AD on a Freightliner chassis, and have enough drain on the engine batteries when stored to drop voltage significantly such that it drops to 10 volts in a couple weeks. Nothing appears to be on. Just replaced the batteries with new Interstates, and have same issue. Nothing appears to be on.....do the computers in engine and trans draw enough to cause this?

Can see the draw at the batteries with a tester, but don't have a clue as to where to look. Anyone run across this before?

BFlinn181 · 04-24-2013, 07:52 PM

Hook your meter between the battery and the cable, then start pulling fuses, one by one. Radio, dash clock, etc. could be drawing battery down. Do you have a battery disconnect for the chassis batteries?

jrgreen · 04-24-2013, 07:59 PM

I am currently working on this same issue and have another post about it here. There also was a post from a couple of years ago with the same problem. His problem turned out to be a stuck solenoid, the one that ties batteries together for emergency start. When he would turn off the storage switches it would not turn off. My chassis batteries were old and I was working on the rig and wore them down. When the coach would not start I tried the transfer switch (coach battery to support chassis battery and start). That didn't work so I replaced all batteries (long story but I had just bought the coach and had reason to believe they needed to be replaced). After that the batteries were losing ~0.1 volt a day and drawing ~0.5 amps with battery storage switches off. Based on the other post and what he did to fix it (tapping solenoid with hammer) I listened for my solenoid (it should clank) to activate and deactivate when using the switches but no noise. My understanding is that if there isn't enough voltage to change it's state (ie when my batteries died), it might get stuck so I tapped it as the other gentleman did. Well after that, with good batteries, it was now clanking when used and there is no current draw when battery switches off. I no longer am losing ~.1 v per day but I know that there will always be some trickle/minimal draw so I need to monitor it more to determine how long I can let the coach sit before starting or charging the batteries. I use it about everyone week or every other week so I don't have longer term data yet. I do check current draw after every trip with switches off and it looks good. I am sure the problem was a stuck solenoid that ties the batteries together, I just need to see if there are other issues/draw that I need to worry about then I will update my original post. BTW, the Battery Control Center (BCC) trouble shooting guide from RV Custom Products states that the Aux start/charging relay coil current is about 0.5 amps - what I was seeing with my meter with the battery switches off.
Good Luck.

cbeierl · 04-24-2013, 10:32 PM

One thing you should do is add a Trik-L-Start to keep the chassis batteries charged up whenever the house batteries are being charged. It of course won't help if you're not plugged in or running the generator. Here's a Winnebago Service Tip with installation instructions: 2006-04 Trik-L-Start -

[I note as I write this that the web address for LSL Products seems to have moved from lslproducts.com to lslproducts.net, so the address in the Service Tip is out of date but the above link should work.]

harmstrong17 · 04-25-2013, 07:48 PM

Thanks for all the feedback. Chris's post put me on to the Trik-L-Start, which was a solution offered by Winnebago for coaches 2005 and older to address the engine battery drain. Winnebago has moved on to another solution, which has a solenoid but the current version of the Trik-L-Start connects between your house batteries and the engine battery bank. If the engine batts are down on power, it pulls power form the house batteries to trickle charge the engine bank. This allows the inverter, if connected to shore line or the solar charger to recharge the house bank.

The advantage here is that you do not have to be attached to shore power to keep your engine batteries up. Other products only work when attached to shore power. Looks easy to install, and for less than $60 can take a crack at the problem. One more example of how this forum can be a great source for help! Thanks again!

cbeierl · 04-25-2013, 09:13 PM

Quote:

Originally Posted by harmstrong17

...
The advantage here is that you do not have to be attached to shore power to keep your engine batteries up. Other products only work when attached to shore power. Looks easy to install, and for less than $60 can take a crack at the problem. One more example of how this forum can be a great source for help! Thanks again!

You don't have to be connected to shore power, but you do need to be charging your house batteries from some source in order for the Trik-L-Start to pass along some of that charge to the chassis batteries. The charging can come from shore power, your generator, or even potentially solar panels (although the default 10A or less solar panel on your coach probably won't keep up with the drains on the batteries).

If the coach batteries aren't being charged no power will be sent to the chassis batteries.

Wayne M · 04-25-2013, 10:55 PM

2008 model Winni, so things are different, but in my case it is necessary (according to Winnebago) to turn the "steps" to the off position. They stated to me that there was more continuous drain with the step switch on than the inverter could supply. The also said that to charge the batteries when plugged in or using solar power to lever the disconnect switches in the on position. Since I have been doing that I have never had a problem, even after 3 months of storage. Prior to that the batteries would be down every 2-3 weeks.

Happy trails

p.s., call Winnebago with your specific serial number and ask that service tech. They have been real good in answering my questions. Each year/model is different to some degree.

clyon51 · 04-26-2013, 08:41 AM

Parasitic drains on MH chassis batteries is as common as MHs not getting great fuel mileage

Many will not even turn the engine over after 2 weeks. On top of that, any battery will self discharge in time without being connected to anything. A battery disconnect on the chassis battery is a good idea for storage, but far from a magic bullet if it's not being charged properly and regularly.

Starting batteries will soon be shot if left in a discharged state very long. They will also not recover from being totally discharged then charged over a handful of times, 10 if you're lucky.

If you do not have a BIRD system, then a Trik-L-Start is a perfect, cheap and dependable option. As has been said, your coach batteries must be kept charged in order to maintain the chassis battery(s). So while camped on shore for long periods or stored with shore, your chassis battery(s) will always be happy.

If you must store without power for say a month or longer, you want both banks totally disconnected. Then every two weeks run the genny for several hours to charge both banks fully and repeat every two weeks. Or, remove all batteries, take them home and keep on trickle chargers. Not doing this will very quickly reduce battery life.

Solar is a viable option if you store in a sunny place. I wouldn't rely on solar if the panel is less than say, 40 watts. My 15w panel is totally useless in Michigan.

cbeierl · 04-26-2013, 10:23 AM

Quote:

Originally Posted by cbeierl

... (although the default 10A or less solar panel on your coach probably won't keep up with the drains on the batteries)....

That should of course read 10W (watt, not amp).

harmstrong17 · 04-26-2013, 10:35 AM

thanks Wayne. I had already talked with Winnebago. In 2006 and later, they installed the Trik-L-Start, or similar device on coaches during the build. So, you have the feature I don't, but will. They now are using a different manufacturer, and the new unit is nearly 3 X the cost of the Trik-L-Start. Funny how that happens.