Community Forums

vancas4 · 09-10-2021, 09:19 AM

My Winnebago-Intent has 2 Deep-Cycle Lead/Acid type batteries. I have owned it 11 months. When the engine is running or plugged into shore power or the generator is running the batteries appear to be charged up based on the control panel reading - 13.8 to 14.1 volts. Once the batteries are no longer receiving an outside source of power for charging, the batteries within a couple of hours appear to discharge to a point below 9 volts and nothing will operate in the coach. This has been a problem almost from the day I purchased the RV. For the last 5 or 6 months I do turn off the battery disconnect switch when I'm not using the RV but that does no good. I have only 30 days left on my warranty so I need to do something. Does any one have any thoughts on this problem that might help??

powercat_ras · 09-10-2021, 09:27 AM

Welcome to IRV2.

I believe your RV has a inverter powered residential refrigerator, the inverter that powers the refrigerator is likely the cause of your batteries rapidly depleting. Besides the disconnect switch, there may be a separate DC disconnect switch for the inverter, that you have to operate when not using the refrigerator to stop the dc power draw from it. You could also reduce but not zero out the refrigerator battery drain by setting the control inside the refrigerator to off, if it has a control that can do that.

I suggest you review your Intent operator's manual chances are it will discuss these features.

Perhaps another Intent owner will chime in and share their solution for this issue as well. Good luck.

AveryF · 09-10-2021, 09:30 AM

There are a number of reasons for the batteries draining, such as a residential refrigerator as powercat ras has suggested.

If you're able to eliminate that as a cause, I'd have to ask if the batteries themselves are suspect. You can have them load tested at a number of places such as Batteries Plus to see if that might be the problem, just be sure to have them disconnected from the charger for several hours first.

Can you check the fluid level? Many deep cycle RV/Marine batteries are NOT "maintenance free" and an improper fluid level will kill a battery in pretty short order. With my bass boat, I have to check the fluid level at least every four to six weeks, especially during the hot summer months, and it usually takes several ounces to top them off.

wolfe10 · 09-10-2021, 09:31 AM

You need to fully charge the batteries and then have them LOAD TESTED. Any place that sells batteries should do it for free.

If wet cell batteries, you can also test them by fully charging and then using a BATTERY HYDROMETER (under $10 at any auto parts house).

Easy to kill a battery by leaving it completely discharged for any length of time. Often happens on a dealer lot.

Epp · 09-10-2021, 09:39 AM

You say you’ve on this coach for 11 months but did you buy this coach new, or used? The batteries might have a date stamp on them so you can find out how old they are.

Persistent · 09-10-2021, 11:28 AM

Lots of good advice above!

There are many possible reasons for these symptoms.

"When the engine is running or plugged into shore power or the generator is running the batteries appear to be charged up based on the control panel reading - 13.8 to 14.1 volts."

These voltages are the output of the converter/charger (possibly inverter/converter/charger). To fully charge lead acid batteries the charging voltage needs to be applied for 14 to 18 hours. Longer if the batteries have been abused.

"Once the batteries are no longer receiving an outside source of power for charging, the batteries within a couple of hours appear to discharge to a point below 9 volts"

You will need a cheap digital voltmeter. Get one from your local hardware store.

There are multiple possible causes for this. Possibly even multiple contributing causes. To narrow down the possibilities, perform this test.
Fully charge the batteries using shore power for 24 hours.
Disconnect the shore power and monitor the voltage.
Voltage should quickly drop to between 13.0 and 12.7. Possibly 30 minutes.
Determine how long the voltage stays above 11.0 volts. This should take much longer, possibly 12 hours.

Battery capacity vs Power used.
Your battery bank may not be large enough to do the job you want.
What is the amp hour capacity of each of your two batteries?

The capacity may be on the battery labels. You may be able to find it by Googling Brand, Model number.

"This has been a problem almost from the day I purchased the RV."

This indicates the power draw is too high for the battery bank size. It could also mean the batteries were defective from the start. Assuming power draw is too high you may be able to reduce consumption.

A compressor type refrigerator also uses excessive 12 volt power possibly through an inverter. Test to see if this is the problem by switching it "off".

120 volt appliances often use excessive 12 volt power through an inverter. Switch the inverter "off".

"This has been a problem almost from the day I purchased the RV. For the last 5 or 6 months I do turn off the battery disconnect switch when I'm not using the RV"

The key word above is "almost". If they worked on day-one, then the problem is most likely yours.

Lead acid batteries must be stored fully charged. Recharge 14 hours before terminal voltage drops below 12.4 volts. Monitor terminal voltage during storage until you know how long you can go between charges.

Without turning the battery disconnect switch "off" as you did not do for 5 months, you should expect 2 or three days of storage without damaging batteries. A full clean 14 hour charge would be required after two days.

Storing batteries for a couple of weeks at 9.0 volts will cause significant "sulfation". This translates to loss of capacity. The deeper the discharge and the longer the time, the more the damage.

I get 5 days using my 200 amp hour battery bank while dry camping. I do not have a residential refer. The refer will greatly shorten that time.

The battery disconnect switch" near the battery disconnects the positive lead from the battery bank. Fully charged flooded cell lead acid batteries may last 6 months before needing recharge.

I wish you good luck and happy trails ahead!

twinboat · 09-10-2021, 12:21 PM

You need new batteries.

Most inverters shut down at 10.5 volts, so thats not whats bringing them down to 9 volts.

The volts your reading when running or shore/generator power is on is charging volts, not battery volts. Switch everything off and watch how low the volts drop.

You could check the water in them, but it may be to late to save them.