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Topic: Engine Batteries not charging (Read 810 times) previous topic - next topic

Engine Batteries not charging

Well, my 1994 U300 has been sitting, plugged into 50amp shore power,for about two months, and the engine batteries have lost voltage. The house batteries are fine and charged to 12.65 volts. The engine batteries had dropped to 11.6 volts. The boost switch was in the off position, The master switch next to the entrance door was in the on position. I have been under the impression that while on shore power both house and engine batteries would be charged from the inverter/charger, through the isolator/boost solenoid panel. Any suggestions as to what to look for or check? ???
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Gerry & Brenda
CHARLOTTE HARBOR, FL
1994 Grand Villa - # 4466
U300 Unihome - 6V92 Detroit
4 speed Allison - Jake Brake

Re: Engine Batteries not charging

Reply #1 –
gerry
I think the manual says that the boost switch should be activated
for 24 hours once a week to keep engine batteries charged.
I  use a trik-l-start to keep the engine batteries charged.

Re: Engine Batteries not charging

Reply #2 –
My understanding is also that unless you turn the boost switch on or use something like a Trik-l-start, the engine/chassis batteries will not charge on shore power.

Michelle
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Engine Batteries not charging

Reply #3 –
The default wiring arrangement does not charge the chassis batteries from the inverter/convertor when connected to shore power unless the boost switch is on. We use a 5A Battery Tender to maintain the chassis battery, while the inverter/converter maintains the house batteries. Other folk use Trik-L-Start, manual switches, relays, boost switch, etc., to maintain the chassis batteries while on shore power.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Engine Batteries not charging

Reply #4 –
Well I think I learned something today. I must have been using the boost switch in the past and I just forgot that it was needed to charge the engine batteries. Must be a senior moment....... :-[
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Gerry & Brenda
CHARLOTTE HARBOR, FL
1994 Grand Villa - # 4466
U300 Unihome - 6V92 Detroit
4 speed Allison - Jake Brake

Re: Engine Batteries not charging

Reply #5 –
Jerry, don't feel bad. I have gotten confused about this issue many times. James Trianna confirmed that by factory configuration the starting batteries are not charged unless the boost switch is turned on. Based on that, I purchased an Ultra Trickle Charger and when I went to install it I disconnected the starting battery cables while the coach was on the charger and found that they were hot when disconnected. I haven't found the reason yet but apparently my starting batteries are being charged when on the 110V AC. The isolater and the boost switch both seem to be working properly so I'm guessing there is a hidden trickle charger someplace on board.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Engine Batteries not charging

Reply #6 –
I had MOT install a charger to the engine batteries for when we are parked.  Nothing else will work except to run the alternator or turn on the boost.  There has been varying instruction Kent on how long I could leave the boost on.  I think the right answer is for quite some time, but at one time the instructions from a salesman was about 4 hours.

I do like the Eco charger that MOT put on.  I hear others use an external charger they simply connect, disconnect.  Mine is built into the coach system.

Good luck.  Mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Engine Batteries not charging

Reply #7 –
If plugged into external AC power you only need a 3 amp Diode, a 1157 tail light bulb, two pieces of wire about 6" long  and a soldering iron. You will also need two terminal to connect to the Isolator.

Poortravel trickle charger.

I will post picture later
1993 U300, 6v92
build 4366
USAF retired, Flight Engineer, C124, C130
 ATP, A & E.  & ex AI

Re: Engine Batteries not charging

Reply #8 –
Quote from: Michael Jackie –
... There has been varying instruction Kent on how long I could leave the boost on.  I think the right answer is for quite some time, but at one time the instructions from a salesman was about 4 hours.
...
I left our boost switch on for weeks. I have seen no ill effects. I did that until I installed a smart charger dedicated to the chassis batteries.

I now only turn on the boost for starting. I have a Battery Tender hooked to the chassis batteries. It is on any time there is 120VAC available at the outlets near the foot of the bed. There appear to be no problems with leaving it hooked up all the time. It charges the chassis batteries with up to 5A. It "floats" the batteries at about 13.32V. That is within 50 mv of the float value on the house batteries, which is provided by the Freedom 25 inverter/converter. I am pleased with this solution to keeping the chassis batteries charged.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX