Poor battery performance when boondocking

[rockeddy]

At rest (about an hour after of charging), my batteries are never over 12.5. The batteries were new 2 years ago. Each time I boondock the batteries have less voltage. I use a CPAP at night. Early this summer I would be at 12.3 in the morning. Now, I am 12.0 or 11.9V after a night of battery use.
Oddly, these Interstate batteries were never more than 12.5 at rest even when they were new. The fact that they are deteriorating has me buffaloed. We are very conservative in battery use when boondocking ..except for the CPAP. Ideas?

[gator.bigfoot]

How are you charging the batteries? Are you using solar or are you charging them before you leave for your trip? Either way you need to look at your charger. I is not charging them properly and most likely not long enough. Please provide more details on you setup.

[wulfraat]

They were likely toast when you bought the trailer. Dealers are notorious for letting units sit on the lot, with parasitic draws, draining the batteries down to <10v and permanently damaging the plates.

So many warranty claims on brand new trailers that as of this year airstream are no longer shipping batteries with new units.

Time for new batteries unfortunately if they are topping out at 12.5v.

If you are reliant on CPAP I would most definitely put 2 lithium batteries in the unit.

[OTRA15]

Originally Posted by rockeddy

At rest (about an hour after of charging), my batteries are never over 12.5. The batteries were new 2 years ago. Each time I boondock the batteries have less voltage. I use a CPAP at night. Early this summer I would be at 12.3 in the morning. Now, I am 12.0 or 11.9V after a night of battery use.
Oddly, these Interstate batteries were never more than 12.5 at rest even when they were new. The fact that they are deteriorating has me buffaloed. We are very conservative in battery use when boondocking ..except for the CPAP. Ideas?

Welcome to the forum! Sounds like your batteries are shot, so it is time to get new ones ASAP. Wulfraat's proposed upgrade to lithium batteries will also require that you get a new battery charger/converter, so you might want to hold off on that IMO.

Originally Posted by wulfraat

They were likely toast when you bought the trailer. Dealers are notorious for letting units sit on the lot, with parasitic draws, draining the batteries down to <10v and permanently damaging the plates.

So many warranty claims on brand new trailers that as of this year airstream are no longer shipping batteries with new units.

Time for new batteries unfortunately if they are topping out at 12.5v.

If you are reliant on CPAP I would most definitely put 2 lithium batteries in the unit.

With your reliance on good batteries, replacing them in kind, with new ones right away, is the simplest quick solution. If you have the time and money, and a longer range perspective, upgrading your electrical infrastructure to include lithium batteries probably makes sense now IMO. Your Airstream, however, will probably be out of action for a while IMO.

FYI this Battery School is a good resource for learning:

http://www.batteriesnorthwest.com/batteryschool.cfm

Happy trails,

[Stickney]

Yes, my batteries in the new Airstream were toast. After battling dealers for sometime I got new batteries. They were only 12.5 resting when new .also. Installed a four-stage converter. After being on float for days they still would max out at rest at 12 five. This did not seem to bother any of the dealers but it bothers me as I think the resting state should be higher and I should end up in the morning with roughly 12 five
I am flummoxed. The new battery option does not seem to be working. The inverter is off-line, and I should have only the standard ghost loads.
Since we are on an extended vacation it seems that I will be limited to shore power.

[OTRA15]

Have you started a new user name?

Something is wrong if you have new batteries and a new charger. Fully charged batteries should read about 12.7 volts, an hour or so after you remove shore power.

Are you sure that your shore power outlet is suppling a full 12O volts?

Also were the new batteries fully charged at the store? "12.5 resting when new" suggests the battery store sold you defective or improperly charged batteries IMO.

Have you checked the Battery School source linked before?

Good luck,

[Al and Missy]

Another option for the initial 12.5 volt reading is voltage drop in the measurement system. Take a digital multimeter and measure the voltage directly on the batteries. You could also measure the current out of the batteries to see if it is reasonable. If not, you can try to track down the source of the drain.

By "the inverter is offline" do you mean turned off at the inverter, or just not in use? It has significant drain when on but not in use.

[Bill M.]

I also run a CPAP. I never get more than 2 years use from flooded cell batteries. So I think your first move is to replace the batteries. You might be fine. If it still does not fully charge I would look at the power converter as maybe an issue. I am not familiar with the converter that Airstream uses in that unit. A email to Randy at Best converter might clear up whether that converter is suspect is some way.

[DKB_SATX]

If your 2-years-new batteries are regular maintainable flooded batteries, get a hygrometer hydrometer and test each cell that way. They're cheap, available from auto-parts stores or Amazon, and offer a fairly definitive reading of the status of each cell.

If batteries are suspect, you need to remove all possible drains when testing. disconnect the batteries, fully charge them with a known-reliable charger (this takes 12+ hours for flooded lead-acid batteries), let them rest and then test the voltage and/or test with the hygrometer hydrometer. One weak-but-not-dead-yet cell will drop the resting voltage, and when they're wired in parallel the pair will appear low.

Also, the meter on the wall in the trailer is... iffy. I think it's measuring voltage at the fuse block, not the batteries, mine reads lower than at the batteries.

[gator.bigfoot]

Are you sure you have the converter set for the correct type of battery? Your charge voltage should be much higher as well as your float voltage. Can you measure your voltages while charging? If they are flooded cells the previous post on using a Hydrometer is a must. Nothing will give you more conclusive evidence than a Hydrometer. If AGM then take a look at the setting for charging AGMs.

[ROBERT CROSS]

From 11.9v...one hour of charging will not be a 'full' charge.
The question..."what are you charging with?" has not been answered.

More info needed.

Bob
🇺🇸

[rockeddy]

Thanks, I have the converter from Randy.

[rockeddy]

Thanks will do

[rockeddy]

I am moving around using solar, generator and land line. Still 2 days on shore pwr will yield similar results.

[rockeddy]

Another odd thing: the 2 or3 as dealers I went to with the first bad set of batteries said, in effect, “ 12.5. V is a full battery, now beat it.”

[Spinonedad]

Make sure something else isn’t drawing down batteries
The following will draw current even when off,

Sub woofer under table
Radio
Fantastic fans If not switched to zero
Also make sure awning light didn’t get switched on by mistake or one of the led lights in storage compartment or closet

There is An automatic draw of 0.i5 Amps per hr due to the carbon monoxide detector you can’t turn off,,,so your 12.6 volt reading will drop day by day without a charge

The victron 712 current meter is a good investment if you are using your batteries for boondocking , as you get an instantaneous reading of voltage and current as needed

[ROBERT CROSS]

Originally Posted by rockeddy

Another odd thing: the 2 or3 as dealers I went to with the first bad set of batteries said, in effect, “ 12.5. V is a full battery, now beat it.”

Yes...but 12.5v does not mean it's a good battery.

It needs to be fully charged, rested and tested.

Bob
🇺🇸

[OTRA15]

Originally Posted by rockeddy

Another odd thing: the 2 or3 as dealers I went to with the first bad set of batteries said, in effect, “ 12.5. V is a full battery, now beat it.”

The dealers are not correct -- 12.5 volts is about 85% charged. See the Battery School link I keep posting . . .

Originally Posted by ROBERT CROSS

Yes...but 12.5v does not mean it's a good battery.
. . .

Nor fully charged!

Originally Posted by OTRA15

. . .
FYI this Battery School is a good resource for learning:

http://www.batteriesnorthwest.com/batteryschool.cfm
. . .

_________________________
Per Battery School:

"12.66 volts = 100% charged
12.54 volts = 90% charged
12.45 volts = 80% charged"
_________________________

So 12.5 volts is about 85% charged.

Suggest sending the Battery School link to the dealers . . .

[lsbrodsky]

You guys are trying to pick the fly shxx out of the pepper. Just because you have a digital VOM does not mean it is calibrated and reading precise voltage. Discerning 12.5 vs 12.6, even assuming the battery is at rest and the voltage is measured at the terminals, is a crapshoot. As has been said, the only precise way is specific gravities.
Larry

[Life is a Highway]

I NEVER though that the fan 0-3 speed selector would be on with the switch not set to 0. I figured they were off line. So that just canceled two current draws.

Originally Posted by Spinonedad

Make sure something else isn’t drawing down batteries
The following will draw current even when off,

Sub woofer under table
Radio
Fantastic fans If not switched to zero
Also make sure awning light didn’t get switched on by mistake or one of the led lights in storage compartment or closet

There is An automatic draw of 0.i5 Amps per hr due to the carbon monoxide detector you can’t turn off,,,so your 12.6 volt reading will drop day by day without a charge

The victron 712 current meter is a good investment if you are using your batteries for boondocking , as you get an instantaneous reading of voltage and current as needed