House Battery Balance Light

[michaeldterry]

Last weekend, while we were underway to Paradise Valley in Dawsonville, GA to meet up with Curtis Coleman (CCMH), the House Battery Balance light on the dash came on and stayed on until we were almost there (about an hour). We were running the generator (as we always do when underway) and had the refrigerator, two CruisAirs, two TV's and the satellite on.

On the way home, the light came on again and stayed on until I parked the bus at the storage lot and shut it down. Nothing we had running (either on generator or shore power while parked) seemed affected and we noticed no degradation in performance.

Yesterday, we went to the bus lot to replace the batteries in our WheelsTo-Go cart that rides in the front bay of the bus. While there, I cranked the bus and the House Battery Balance light was on again! (Note: We keep the bus plugged in to 50 amp power always when stored).

At the risk of confirming my ignorance yet again, I'll confess I have no idea what is causing this light to come on or what (if anything) I need to do about it. We rarely use the bus without either generator or shore power - at the most, on battery power for a few minutes at a time.

Can I get some advice and/or guidance from the POG braintrust?

[Jon Wehrenberg]

Michael,

That light is a chassis related indicator. There is nothing you were doing that I can see had any impact on that warning light.

For the benefit of those who might experience the same situation it is driven by a Vanner monitor which on my coach is located on the forward bulkhead above the chassis batteries. It is a box about 4" square with several wires attached to terminals across the bottom.

Electrical components 004.jpg

You either have an issue with the Vanner Equalizer or the monitor is giving you bad information.

The easiest way for me to determine if it is the monitor is to check the voltage on the 12 and 24 volt inputs. If the equalizer is functioning as intended it maintains the 12 volt reading at 50% of the 24 volt reading within about 1/2 volt.

In other words, with the engine running the 12 volt reading might be 13.7 volts and the 24 volt reading might be 27.5 volts. The lower reading is within .1 volts of being exactly 50% so it is within range.

If your 12 volt readings are 1/2 of the 24 volt readings within 1/2 volt the monitor has likely failed. If they are out of range the equalizer may have failed or is about to fail. That can be checked by following the Vanner instructions found on line or in your operator's manual.

The purpose of the battery balance is because on the chassis the bus uses both 12 volts and 24 volts. The equalizer is set up to insure all four batteriies' voltages are being maintained even though the loads may be disportionate.

[Mark3101]

I had the same problem the day we got the bus. It was the equalizer, not the monitor, and Prevost Ft. Worth changed it out on the spot. They indicated that they were having issues with some of them, and we were in and out in about an hour. Technician checked the voltages as Jon indicated and went right to the parts guy and came back with a shiny new one in the box.

Haven't had an issue since.

[truk4u]

Michael,

If after you check the Equalizer like Jon said and find it's the Monitor, there's one on e-bay here:

http://cgi.ebay.com/ebaymotors/Vanne...ht_1099wt_1161

Jon's is a 70A and this one is a 70D because Vanner keeps updating.

[Jon Wehrenberg]

My guess is the updates have been to improve reliability. A lot of the POG owners have replaced their monitors.

[michaeldterry]

Michael,

If after you check the Equalizer like Jon said and find it's the Monitor, there's one on e-bay here:

http://cgi.ebay.com/ebaymotors/Vanne...ht_1099wt_1161

Jon's is a 70A and this one is a 70D because Vanner keeps updating.

Unfortunately, the guy who listed the Vanner EM70D on eBay sold out of them before I could check out the listing. I contacted him, but he doesn't have any more now. Thanks for the heads up anyway!

[Jon Wehrenberg]

Michael,

I lean towards the monitor being the problem, but before you purchase a new one it is worth checking to confirm it is bad. It could be a bad equalizer.

[Gary Carmichael]

Damn! you guys are good! So much knowledge Michael, we are blessed to have people with this info on POG but that's what it's all about.

[rfoster]

Gary: The early and old members of POG received the "Magic Decoder Ring" and membership card for their 50 bucks. Inflation has run the membership to a 100 bucks but no ring and no card.
Just good advice.

[JIM CHALOUPKA]

That ring is invaluable: