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Battery Voltages

August 19, 2015, 09:01:25 pm

Not our day (see our other post on wheel stud failure to torque properly).

We're unintentionally dry camping tonight at a truck tire dealer (see above).  I'm taking the coach to Tennessee RV next week to have the generator repaired — hopefully!  Only Line 2 works.  Thankfully, it runs the bedroom air conditioner and the generator is running like a champ at the moment, despite it having boiled off about a pint (?) of coolant on a 100 degree day in June (the same day Line 1 went to zero volts).

But my question of the night is about battery voltages.  I have three sources:  the analog gauge on the dash (when the engine is running), an Amazon cigarette lighter voltage readout in one of the 12V outlets on the dash, and a SeeLevel panel in the bathroom. 

If I understood the previous owner, the way he installed the SeeLevel, the "Battery" reading on that is engine/start battery voltage.  It's currently 12.1V and has been falling.  No guarantee I understood correctly, however; the coach's previous owner way above my level on coach systems.

The Amazon cigarette lighter readout plugged into the bottom 12V outlet on the dash shows 12.5.  Is that reading house batteries?  The same device in the upper 12V outlet on the dash reads 12.6-12.7.  I heard from someone, probably erroneously, that one of the 12V outlets on the dash is house batteries and one is engine/start batteries?

When the engine is on, the dash jumps to 13.3 or higher and the analog gauge shows 12.8-12.9.  We're totally confused and don't know which to trust for what.  Worse still, the voltages seem to be dropping and we don't have a single 12V device on in the coach: no lights (using a battery-powered lantern), nothing other than intermittent use of the water pump.

We really want to be able to dry camp fairly extensively, even if not under these circumstances!  (There are prettier places than truck tire dealer parking lots.)  But we don't feel confident getting through tonight with adequate house voltage AND the ability to start the engine in the morning.

We're probably just tired and frustrated by today.  But as long as our AT&T UnitePro router and laptop batteries hold out, we'll be checking the Forum tonight for any thoughts.  I'm at 40% on the laptop, so we're shutting down right now for a while.  Big thanks in advance, to all.

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Re: Battery Voltages

Reply #1 – August 19, 2015, 09:20:46 pm

Your generator isn't charging your batteries.  Do you have your inverter charger off?  The bottom cigarette port is your engine bank and the upper one is the coach bank.  I'd check your remote inverter panel(Link 2000?) to make sure the charger light is on.  If it is, I'd turn off the A/C's and see if the battery voltage comes up.  Maybe the charger is on the other generator output leg.  If that's the case, you'll have to manage your batteries through the night so you can start in the morning.

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Reply #2 – August 19, 2015, 09:40:43 pm

OP's inverter charger is almost certainly on L1 along with the front air.

So with only one leg of the genny, no charge to batteries.

Not familiar enough to say, but there should / may be 120 outlets that are on Leg 2 so as to charge the toys. They would be outlets not on the inverter. Like maybe the washer dryer or back of the fridge.

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Reply #3 – August 19, 2015, 09:45:38 pm

keep in mind with "nothing" on you probably still have the fridge circuitry, the CO and propane monitors running among other house systems... all small parasitic drains on the battery. Mine drains slowly with no use, I keep it parked in a location with no power and need to run the generator once a week or so to keep the batteries charged.

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Reply #4 – August 19, 2015, 09:48:27 pm

A  battery charger is always handy to take along.

Somewhere in the coach a 110 outlet should work allowing an extension cord to power the charger and to allow you to charge the house batteries seperate  from the coaches built in system

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Reply #5 – August 19, 2015, 10:51:36 pm

Thanks for all the good, quick replies.

Brett, our charger seems to be on Line 1 of the generator — the leg that is down.  Bedroom air, the refrigerator, and AquaHot 115V switch appear to be on Line 2.  Don't know for sure.  Just reporting what we see.  And thanks for the insight as to what the two 12V outlets on the dash show.  Bottom engine, top coach would be consistent with what we're experiencing.

Matt, you're right — there are a lot of small draws on the battery.  As we sat here and ate dinner by the light of a battery lantern, we realized that the monitors, fridge 12V circuit board (even when it's running on propane), etc., are all using 12V.

Bob, I think we're going to grab 110V from the tire store's sign tomorrow morning to power our coffee maker and Susan's hair dryer.  At least they have an outlet on the post the sign is mounted on, and we have a 50' extension cord on a reel.  She has to go to work in the a.m., and that demands coffee and a hair dryer!

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Reply #6 – August 19, 2015, 11:07:47 pm

You could temporarily swap L1 and L2 to the main breaker in your electrical panel to allow you to have power tonight.  Just make sure you disconnect the appropriate power while doing the swap. 

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Reply #7 – August 19, 2015, 11:09:27 pm

Why wait?

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Re: Battery Voltages

Reply #8 – August 20, 2015, 12:23:40 am

.....to grab power ?

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Reply #9 – August 20, 2015, 12:26:03 am

.....Yes in your case it would be wise to plug in ---just in case
JohnH

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Reply #10 – August 20, 2015, 06:59:44 am

You could look at the transfer switches. Sounds like one leg is loose. 

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Reply #11 – August 20, 2015, 08:33:15 am

Plug into 110 by sign and turn on charger now?

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Reply #12 – August 20, 2015, 11:45:56 am

Thanks, all.  We made it through the night running the generator to power the bedroom air.  Then this morning, I ran a line out the bedroom window for coffee and Susan's hair dryer.

As to "why wait," you're absolutely right — except that we had every conceivable power adapter for the coach (I thought), except of course the combination that would take our 50A power cord down to 30, and then 30 down to 15.  We'll remedy that next week at Tennessee RV, unless someone knows a better source/better solution.

Coach batteries held up overnight, thankfully, and it started this a.m.

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Reply #13 – August 20, 2015, 12:07:35 pm

Walmart

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