Did I kill my coach house batteries?

[mgoodin08]

Hi, new to RV'ing and to this RV we have owned for a year- a 2005 Winnebaago Itasca Sunrise 33br, Workhorse drive train. WE added two additional storage batteries for a total of 4. 2 of them brand new, two of them older but were still good. After putting it in storage and putting a cover on it the solar does not charge the house batteries, of course. So after a month I came to start it up and check on things and EVERYTHING was completely dead.

I jumped the engine battery and let it run for an hour, jumped the Onan 5k generator and let it run for an hour and now the engine battery stays charged fairly well but NOTHING- ZIP ZERO on the house batteries.

DId I kill the house batteries by letting them run dead for a couple weeks? Do I have to take them all out and put them on a trickle charger at home?

Thinking I could cut a slit in the cover and expose the solar panels so they could charge the house batteries?

I'm kind of at a loss. I'll be quite bummed if the almost brand new $500 each batteries we added are toast.

In the future I'll either have to disconnect the negative batter terminal to keep them charged or expose the solar panels to keep them charged. If disco'ing the neg battery terminal can I just disco the FIRST battery in line or do I have to disco all 4 batteries?

Thanks in advance- always get good answers from folks in this forum.

 

[John From Detroit]

Hard to say... Did you DISCONNECT the house batteries either by use of the USE/STORE (or AUX battery) switch perchance... Once the engine was running they should have gotten charged via the isolator but you need to re-punch the button With the generator running as well they should have gotten additional charge from the converter but they need to be CONNECTED.

If it's a USE/Store 3 position rocker that's a remote control (if it's a 3 position switch momentary use/store or on/off and spring return to center no matter how it's labeled this applies)

The actual "Swich" is a magnetic latching solenoid and it needs battery power to work.

page 2: On mine the )Q@#*%$ remote switch failed.. I was able to fix it for nothing but it when it failed "STORE" worked great (Turns off) but USE.. not so good.

 

[ferfer]

IMHO first need to get the house batteries charged. One hour is not near enough time. I do not think you ruined the batteries but...

The best way to charge the batteries is to use the coaches converter/charger to charge batteries. The mixed battery ages may effect the state of charge (SOC) by equalizing to less robust set but still batteries should charge.

If you have 120VAC available, use appropriate adaptor on power cord to plug into 120V power. If no power available use the generator. If the batteries accept a charge it will take greater then 5 hours depending on batteries SOC.

Discussion of the use of different dated batteries, use of disconnect switch for storage etc. will be of more value once/if batteries are charged.

 

[Mark_K5LXP]

In order for there to be ZIP ZERO during alternator or shore power means there's a disconnect between the source and the batteries even if the batteries were dead flat. So some investigation is required to see where the charge source is disappearing. Could be the salesman switch, a fuse, or a DC breaker.

Mark B.
Albuquerque, NM

 

[Domo]

When leaving the rig for more than a few days I turn off the disconnects and remove the ground wire off the chassis and coach batteries. That eliminates any parasitic drain such as CO/propane monitor and the idle inverter.

 

[mgoodin08]

When leaving the rig for more than a few days I turn off the disconnects and remove the ground wire off the chassis and coach batteries. That eliminates any parasitic drain such as CO/propane monitor and the idle inverter.

If I disconnect the negative ground on the first battery in line that sufficiently disconnects all batteries, right?

 

[mgoodin08]

IMHO first need to get the house batteries charged. One hour is not near enough time. I do not think you ruined the batteries but...

The best way to charge the batteries is to use the coaches converter/charger to charge batteries. The mixed battery ages may effect the state of charge (SOC) by equalizing to less robust set but still batteries should charge.

If you have 120VAC available, use appropriate adaptor on power cord to plug into 120V power. If no power available use the generator. If the batteries accept a charge it will take greater then 5 hours depending on batteries SOC.

Discussion of the use of different dated batteries, use of disconnect switch for storage etc. will be of more value once/if batteries are charged.

Hard to say... Did you DISCONNECT the house batteries either by use of the USE/STORE (or AUX battery) switch perchance... Once the engine was running they should have gotten charged via the isolator but you need to re-punch the button With the generator running as well they should have gotten additional charge from the converter but they need to be CONNECTED.

If it's a USE/Store 3 position rocker that's a remote control (if it's a 3 position switch momentary use/store or on/off and spring return to center no matter how it's labeled this applies)

The actual "Swich" is a magnetic latching solenoid and it needs battery power to work.

page 2: On mine the )Q@#*%$ remote switch failed.. I was able to fix it for nothing but it when it failed "STORE" worked great (Turns off) but USE.. not so good.

This makes sense. A few weeks ago- the first time I showed up and stuff was dead, I ran the engine and generator for about an hour and it DID charge up a tiny bit. I did use the battery disconnect switch I found in the house but it didn't do the trick- batteries were dead again a few days later (not the engine battery, though). So maybe I need to hit that switch again with the generator running to get charging to go to the house batteries again?

Easy enough to pull a negative cable in the future- takes all of two minutes so I'll be doing that.

Sorry about your switch failing! That's no fun.

 

[mgoodin08]

In order for there to be ZIP ZERO during alternator or shore power means there's a disconnect between the source and the batteries even if the batteries were dead flat. So some investigation is required to see where the charge source is disappearing. Could be the salesman switch, a fuse, or a DC breaker.

Mark B.
Albuquerque, NM

Yeah I think maybe I didn't reset the switch properly after trying to attempting to use it to disconnect. Lots of learning with this rig! I'm getting there, though!

 

[ferfer]

maybe I didn't reset the switch properly after trying to attempting to use it to disconnect

The battery disconnect switch, located by the entry door, will turn off most 12V systems but not the steps, battery controller and monitor system. Your system may be slightly different. If your battery disconnect is Intellitec Battery Disconnect Relay toggle switch will be label USE - STORE. Use STORE to turn off 12V system.

A quick way to confirm if battery disconnect switch has disconnected the batteries is see if the 12V ceiling lights will turn on. You are not diconnected if turn on. NOTE: This will not work if connected to 120V as the converter will supply power to 12V systems.

 

[Ray-IN]

The only way to be positive a battery is disconnected is to remove the negative cable, OR place a knife-blade disconnect on the negative battery post.
mgoodin08, Yes, if the ground cable is removed leading to the chassis the battery (bank) is completely disconnected. The normal lead acid battery charge loss is 3%/month with no connections, of course LIPo4 battery % loss is much less.
There is a caveat; if the inverters charge function is not turned off manually, it's constantly monitoring battery voltage = a small phantom battery drain.
FWIW, most inverter/chargers will not charge a fully discharged battery, it requires a stand-alone battery charger to bring them up to ~5-10% SOC for the inverter/charger to kick in; in other words the inverter/charger must "see" voltage to work.

 

[Kirk]

WE added two additional storage batteries for a total of 4. 2 of them brand new, two of them older but were still good.

You need to define "still good." When batteries are in parallel, the best battery will only charge to the level of the worst battery. With 4 batteries it could be two pairs of two 6V batteries in series or it may be four 12V batteries in parallel. Either way, the worst battery there will control the charge levels. In addition, for any flooded cell battery to go down to less than 10V will do permanent damage and the lower it goes the more damage. Chances are that you now have 4 batteries with matching poor condition.

I ran the engine and generator for about an hour

An hour is not nearly enough to charge even the chassis battery. Even with the best battery charger it will take 6 - 8 hours with batteries in good condition. Of course, if the batteries are in poor condition the reach full charge much more quickly because the capacity in now small.

 

[Gary RV_Wizard]

If I disconnect the negative ground on the first battery in line that sufficiently disconnects all batteries, right?

Maybe not if they are 12v batteries wired in parallel. The sure way would be to disconnect the cable from the LAST battery negative post to the chassis ground lug.

 

[Kirk]

Maybe not if they are 12v batteries wired in parallel.

The negative cable should always be lifted first and with a parallel connection just make sure that you lift the one that connects to chassis ground.