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TandCplusRV · 10-03-2013, 10:52 AM

Getting ready for a trip tomorrow. Motorhome has been sitting a bit. Started up OK this morning but the panel showed bother house and chassis at 12.1 volts. I'm sitting here in storage trying to run the generator enough to bring the charge up enough so that the fridge won't kill it overnight when I come back to turn it on this evening. How long do I have to run the generator to "top off" the charge? 2006 National Seabreeze.

96 Wideglide · 10-03-2013, 11:06 AM

From 12.1V , several hours.
Why not run your fridge on propane overnite ?

TandCplusRV · 10-03-2013, 11:09 AM

I plan to run on propane but I think the fridge uses electric as well....or am I wrong? Fridge seems to require the battery disconnect switch not be off for it to come on so I assumed it would draw from the batteries.

clyon51 · 10-03-2013, 11:18 AM

If your charger puts out 14.4v (boost mode) it will take about 3 hours to get them up to 90% charged (12.5v). That may be more than you need just for overnight. It also depends if you are talking running the fridge on LP or on 120v via inverter.

clyon51 · 10-03-2013, 11:23 AM

Quote:

Originally Posted by TandCplusRV

I plan to run on propane but I think the fridge uses electric as well....or am I wrong? Fridge seems to require the battery disconnect switch not be off for it to come on so I assumed it would draw from the batteries.

The fridge needs 12vdc to operate the control system, so yes it draws from the batteries on LP, but not that much. If you shut everything down except the fridge (leaving BDS connected) 2 hours should be more than enough.

96 Wideglide · 10-03-2013, 11:27 AM

Quote:

Originally Posted by TandCplusRV

I plan to run on propane but I think the fridge uses electric as well....or am I wrong? Fridge seems to require the battery disconnect switch not be off for it to come on so I assumed it would draw from the batteries.

Yes, it does. Very little draw thou.
If you have an ice maker running, it may use some extra 12V.

TandCplusRV · 10-03-2013, 11:40 AM

Thanks for the replies folks. As a total rookie, I have my dealer's service manager on speed dial. Interestingly, he told me that the average voltage on the motorhome's panel should read 12.1 to 12.3 while stored - this is counter to much of what I've read online. Battery stuff panics me a bit as we've run the gamut battery wise the past few months. Had the pair replaced but still showing low voltage very fast so have disconnects installed now for both house and chassis.

tderonne · 10-03-2013, 01:59 PM

You probably have a single stage converter, not a multistage charger. You may be better off starting the engine for a while, since the alternator works at a higher voltage.

mel s · 10-03-2013, 02:14 PM

Quote:

Originally Posted by TandCplusRV

Getting ready for a trip tomorrow. Motorhome has been sitting a bit. Started up OK this morning but the panel showed bother house and chassis at 12.1 volts. I'm sitting here in storage trying to run the generator enough to bring the charge up enough so that the fridge won't kill it overnight when I come back to turn it on this evening. How long do I have to run the generator to "top off" the charge? 2006 National Seabreeze.

TandCplusRV
The time will depend upon what battery charging capabilities your motorhome has on board.

If you have a high amp battery charger built into your converter it may take only a few hours.
However, if you have no battery charger, (or a low amp charger) it could take as long as a few days for the genset to charge the batteries.

BTW, some coaches chassis batteries only charge via the alternator, (when the engine is running).

Mel.
'96 Safari, Freedom 20 inverter with built in 100 amp 3 stage charger.

clyon51 · 10-03-2013, 02:17 PM

Quote:

Originally Posted by TandCplusRV

Interestingly, he told me that the average voltage on the motorhome's panel should read 12.1 to 12.3 while stored - this is counter to much of what I've read online.

It is and his advise is bad. If batteries cannot be left on a charger 24/7, then they should be fully charged (12.6+ volts) and disconnected. Batteries do self discharge over time, but only about 5% per month. So in 3 months, the voltage would be in the 12.46v range. As a battery discharges, lead sulfate collects on the plates. By 12.1v, all plates are covered. If not recharged soon, the sulfate hardens and the battery loses life.

96 Wideglide · 10-03-2013, 02:21 PM

Quote:

Originally Posted by tderonne

You probably have a single stage converter, not a multistage charger.

Unlikely on a 2006 National RV.

TandCplusRV · 10-03-2013, 02:35 PM

Quote:

Originally Posted by clyon51

It is and his advise is bad. .

Thanks Cylon. That's what it seemed to me but nice to have a second voice confirming things. The motorhome has been in for service for the past 18 days. Batteries were replaced and fully charged when left with the dealer. Disconnects were installed on both the house/chassis batteries amongst other things during the 3+ weeks it was with them. Engine/Gen ran for about 1 hr each after pickup last night and then the coach went straight to storage. 12.1 when I went over to gas her up and load up today. :-/

I'm going to be plugged in to 50amp Friday-Monday so hopefully the batteries will fully charge and when I disconnect them in storage next week they'll be holding at a higher level.

Service has been great otherwise, but all this back and forth with the batteries is becoming irritating.

96 Wideglide · 10-03-2013, 02:53 PM

Do you have an inverter, that was mabe left on

?

TandCplusRV · 10-03-2013, 02:56 PM

Nope. No inverter. Old coach batteries tested bad and wouldn't hold a charge but I suspect they'd been run down one too many times. These new batteries have only been in about a month and it's been sitting at the shop the entire time other than the first week. I haven't really had a chance to see if they hold a charge once they're full up because I took it straight to the dealer from vacation last time out.