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Topic: Need help on road - battery troubles? (Read 3 times) previous topic - next topic
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Need help on road - battery troubles?
Yahoo Message Number: 111012
Howdy all!  The Hill family is headed to Disney...and have had a few of our normal RV surprises to make the journey fun.  Tessa is currently driving as her adoring husband (that's me...the Nedchanic) enjoys the ride!
 So here's the issue/question...when we start Ciao, the battery seems weak.  It seems to turn over slowly - and a couple of times, we've had to re-try as it stopped turning over after a couple of weak turns.
 However, when I put a voltimeter to the battery, it reads a strong 14.4V.  The battery is an Optima Yellowtop - not even two years old... so I would think it should be ok.  And the strong voltage makes me think it is.  But something definitely seems off.
 A bit more background.  Last night, we stopped to have dinner.  The generator had a bit of trouble cranking, turning many, many times before cranking up - but it did crank.  After dinner, when I cranked Ciao, the red "Amp" light came on and the battery meter read much lower than normal.  Normally, the gauge points to the M or A in NORMAL.  Instead, it was pointing to the O - and when I turned the lights on (it was dark) with the engine idling and generator off, it went even lower.  We stopped doing anything, slept for the night...and all appeared well in the morning.  No amp light, normal battery gauge reading, etc.  Until we started having the weak cranking problem.
 One last thing...Before leaving yesterday, Tessa hooked up an air compressor to the coach batteries (less than 2 year old T-105's), the air compressor did not run.  She then hooked the compressor up to her van's battery - so it's not the air compressor.
 Coach battery cables seem ok, water in coach batteries are full and well maintained, solar seems to be pulling fine.
 Is is: 1. isolator, 2. Time for a new cab battery (50k miles), 3. bad ignition switch, 4. something else???
 So, the Nedchanic humbly requests the wisdom of the list's gurus.  What thinkist y'all?

Thanks!

Tessa's adoring husband :)
Need help on road - battery troubles?
Reply #1 –
Yahoo Message Number: 111014
Hi

I'm a little confused about what your trouble is. It seems you are saying you are having problems with both the house battery system and the motorhome starting battery system, at the same time. The only thing common in these two separate systems is the isolator. You might want to eliminate that possibility. That's probably what I would do. Disconnect the isolator temporarily.

To do this follow these instructions.
1) remove the ground wire from its terminal on the house batteries.
2) remove the ground wire from its terminal on the starting battery.
3) remove the two outside wires from the isolator. No need to  disconnect the center wire
4) tape the ends of the wires you removed from the isolator
5) reconnect the ground wires to the batteries
 Now see if you still have problems. If not, it would seem your isolator was at fault. If your problems persists, reconnect the isolator taking all due precautions as you did when you disconnected it. Good luck and keep us posted.

ps It wont hurt anything to drive with the isolator disconnected.
You wont be recharging batteries from your engine is all. But get a new one as soon as you can or you may run down your starting battery ;>(

Tom Johnston
Re: Need help on road - battery troubles?
Reply #2 –
Yahoo Message Number: 111017
Ned When you say you have 14 volts is that with a load on the battery. Lights on or someone trying to crank the engine ect. A voltage test with no load doesn't tell you a lot about the state of the battery. Actually that sounds to high unless the engine is running or something else was charging the battery at the time..
 To see if your battery is packing any punch check the voltage at the battery terminals with a load on the battery. A lead acid battery will have about
2.2 volts per cell when charged and supplying a modest load. (Thats 13,20
 total)  Turning over slow or weakly is often a sign of a started dragging...
This is treating the chassis battery as a stand alone. The coach battery is a different item but could well be related....
 If the generator turned over a long time it sounds as if that battery had taken some charge.. Turning slow is an indication of a weak battery(along with other possibility's) but turning fine and not cranking is usually due to being a long time since it was ran and slow to get fuel or something similar.
 The gen light and low indicated voltage is usually a charging system indication. How long has ot been since all the battery terminals were cleaned?

Good Luck and watch out for Mickey...
Garry
Re: battery troubles?
Reply #4 –
Yahoo Message Number: 111020
My hunch is that if you have nearly new, high-quality battery that tests well under no load, the most likely cause is a bad connection from the alternator. That would also account for low house batteries, since only the alternator charges *both* the house and engine batteries.
 Check all your cabling from alternator to battery, and clean your terminals (including those on the starter motor). Also check your belts--if the belt slips going around the alternator pulley, you could have the same symptoms.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
 
Re: Need help on road - battery troubles?
Reply #5 –
Yahoo Message Number: 111101
Thanks all for the helpful analysis and troubleshooting.  Thankfully, Ciao did fine the rest of the way and we made it to Disney fine.  And Tessa just tried cranking after Ciao sat for 2 days and it did fine.  So it's a bit of a mystery.  But I plan to use your tips today to see what I can figure out.  A good excuse to pull out the voltimeter and tinker a bit :)

Thanks aga