Community Forums

tiredvet · 06-08-2015, 05:58 PM

I let the coach sit for a month with no shore power,went to start it and batts are very weak.First thought was it's time for new start batts.I plugged the coach in and 24 hours later the batts are at 12.74. I did a load test and past with flying colors so next I checked for a parasitic draw and found nothing. I remember reading an older thread where Old Scout said that he had an issue with battery drain if the chassis and or house disconnect switch was left on with out shore power for a few days? If so my 2003 is like wise.I like the idea of not dropping $345.00 for batts but I sure would like to know why it draws the power out of my batteries in a few weeks time. Have other folks with early coaches run across this.

Skip426 · 06-08-2015, 08:13 PM

You should have been able to detect a draw from , the engine and transmission controllers , and those draws can drain the batteries ( chassis) in 3 weeks to a month. Disconnecting the batteries will result in a re-learn time on start-up and possible stall and rough shift during the first 10 >20 mins. of operation.

Old Scout · 06-08-2015, 08:54 PM

Cant explain why you would not see the phantom draws on your meter but as a practical matter, I can tell you that there are a number of things that by-pass the battery cut-off switches and are hot wired to the bats. The largest draw on the house side is the inverter--I have found that by putting the Zantrex 2000 in hibernate mode, the draw on my coach bats [I store the coach off the grid] is substantially reduced.
On the chassis side, things like the starter/starter solenoid are direct wired. Suspect there are other 12v draws on the chassis side but am not sure what they would be. Point is--if you shut-off the bat switches, then disconnect the battery cable connections--you will see a fairly good spark. So even with the bat disconnect switches off--there is still a draw.
PS--an added feature of putting the Zantrex in hibernate is that as soon as you restore 120v power [genset or shorepower], the inverter immediately goes to bulk charge and as far as I can tell--all system default settings are retained--this has been a major issue for me in the past--having to force the inverter to bulk charge--like while at Quartzsite.....

EngineerMike · 06-11-2015, 02:41 PM

I researched this extensively, at every technical level.
Despite the masculine look from the outside, the Peak Chassis is female. Ignore her & she quits putting out.
Just let her know you care and are thinking about her, and this problem goes away.

DrDaveMA · 06-11-2015, 03:34 PM

The solar array bypasses the battery disconnect, so the spark you see maybe the cells trying to CHARGE the batteries, not discharge them.

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Dave, Bobbi and Fenway

TRAKKER · 06-25-2015, 01:38 PM

I do not leave my coach plugged when not in use (I do not like the inverter running all the time) so my coach batteries go dead after a short while. I installed a five amp Battery Tender to keep them charged and that works. My chassis batteries did not go dead but failed completely every two years (is this normal?). So I put another five amp Battery Tender on the chassis batteries. We will see if that helps. By the way I discovered the refrigerator was connected directly to the batteries so I moved that line to the switched panel.

bcbowers · 06-25-2015, 10:58 PM

Rick (& others),

I believe you'll find that a "Battery Maintainer" is designed to put out approximately 12.8V immediately or after it determines that the batteries a fully charged (depends on the manufacturer). If you apply the "Battery Maintainer" on the "House Batteries" thinking that they "Chassis Batteries" will stay charged as they do when the on-board Inverter/Charger is used, think again!? The Inverter/Charger will keep the Chassis Bats charged via an Echo Charger (older models) or "Charge Relay" newer model that "shares" the charging voltage & current. However, if the charging voltage does NOT reach or exceed 13.0V, there is NO sharing (by design).

I believe using a "Battery Maintainer" directly connected to the Chassis Bats will keep them from going dead. I would still recommend a "Full Charge" periodically (monthly?). Some battery maintainers will effectively perform a full charge before entering a "Maintenance Mode (trickle charge)". If yours operates in that manner then simply disconnect it and immediately reconnect it to re-initiate a full charge.

FWIW, I recently found an inexpensive ($53) Schumacher 12-Amp 3-Stage Charger Model SS-120A-PE specifically designed for deep cycle RV/Marine batteries. Once the "Monitor Mode" is reached (Stage 3), the batteries are maintained at 13.2V. This means that my Echo Charger is keeping the Chassis Bats at just over 13.0V. Perfect!