Need help: discharged coach batteries

[Schvarak]

Originally Posted by Herk7769

Its telling you that you are reading the wrong side of the monitor. Those readings are for the tanks, not the battery. Look to the other side for "C", "G", "F", and "L".

Yes, I tried to correct that[emoji4] Unfortunately not very astutely!

[Herk7769]

Originally Posted by Schvarak

Whoops 😁Top is C for charge, 2nd is good, 3rd is F fail? Bottom is L for low?

Yes, F is "Fair"

The actually voltage that "turns OUT" the light is what is important since there is really no way to tell what the status is "in between" lights.

[Schvarak]

Originally Posted by Herk7769

Its telling you that you are reading the wrong side of the monitor. Those readings are for the tanks, not the battery. Look to the other side of the label for "C", "G", "F", and "L".

A bleed down that fast your battery is either powering a largish power drain, was NOT fully charged at all, or has lost so much capacity that they will never have any staying power. They should be load tested at a place that specializes in storage batteries.

Your disconnect switch can go on either terminal; it does not matter.

That's why I was asking about the radio not being turned off? I'm hoping the disconnect switch will fix that.
How bout the Fuze holder that's mentioned by Scott?
I may end up replacing the batteries afterall.

[Herk7769]

Originally Posted by ScottBrownstein

If you install it on the left rear negative post with the cable that goes to the chassis, you will avoid worrying about that in line fuse holder which is a parasitic load. Pull the ground and everything is disconnected. 125 amps should be enough.

I agree completely. In your installation the disconnect would be most convenient on the ground terminal.

[Schvarak]

Originally Posted by Herk7769

I agree completely. In your installation the disconnect would be most convenient on the ground terminal.

Then, that's where it's going!

[Herk7769]

Originally Posted by Schvarak

That's why I was asking about the radio not being turned off? I'm hoping the disconnect switch will fix that.
How bout the Fuze holder that's mentioned by

That fuse is most likely for the propane leak detector. As long as your tank is turned off at the valve you can isolate everything without worry. I would NOT recommend using the disconnect if you are using gas or staying in the camper.

[Schvarak]

Originally Posted by Herk7769

That fuse is most likely for the propane leak detector. As long as your tank is turned off at the valve you can isolate everything without worry. I would NOT recommend using the disconnect if you are using gas or staying in the camper.

Lp tank is turned off at the valve.
Disconnect will be used only when in long term storage/not in use or to charge the batteries as needed. Especially if I'm on shore power or generator.

[ScottBrownstein]

You had me till generator. The disconnect switch is to isolate the batteries so that they will not discharge only during storage. If you disconnect you will not be able to use the generator or converter to charge the batteries...since they are...disconnected!

[Schvarak]

Originally Posted by ScottBrownstein

You had me till generator. The disconnect switch is to isolate the batteries so that they will not discharge only during storage. If you disconnect you will not be able to use the generator or converter to charge the batteries...since they are...disconnected!

I said that wrong can't be disconnected when charging etc or using genetator. Sorry about that. 😑

[Schvarak]

Wow! Was an easy installation of the disconnect switch! Less than 5 minutes. Voltage was 11.94 this morning, down from 12.1 yesterday. Am charging now, will disconnect from main switch and the new disconnect switch. Will give it a few days and see what happens. 🙄

[Schvarak]

Btw, when disconnect switch is active/off, can i do a voltage test without turning the ground on?

[BillMFl]

Originally Posted by Schvarak

Btw, when disconnect switch is active/off, can i do a voltage test without turning the ground on?

The best way for you to deal with your batteries for sure now is to pull both out and charge them overnight. Use your volt meter on each battery separately. Immediately after full charge they should read 13.1 volts minimum depending on the charge rate of your charger. Most chargers have a bulk rate of 13.5 to 14 volts that then drop down to 13.1 maintanance rate. A fully charged battery will hold that 13.1 for awhile but eventually drop to 12,7 to 12.9 which it will then hold as fully charged if the battery is ok. If the battery is sulfated it will not hold at 12,7 but will keep dropping even without any attached drain! One or both of your batteries could be damaged by sulfation and you need to separate them to know for sure. While they are out and separated you can take them to a Sam's Club for a free load test. Other shops will likely do it for free too since they know you might need to buy new batteries and they hope you will buy from them after the test. Last summer I bought two AGM sealed glass mat batteries from Sam's club. They cost about $120 each. They use fiberglass mat instead of lead plates and can withstand deep discharge and recover way better than lead acid batteries. And because they are sealed you don't have to worry about adding water. I used similar but larger AGMs in my 43' Trawler and they last much longer than lead acid batteries and can survive multiple deep discharging that would destroy lead acid batteries. The AGMs at Sam's are a bargain and have plenty of capacity unless you boondock a lot in which case you would want Group 29 or 31 sized batteries for more amp hour capacity. The Sam's AGMs are working fine in my 37' Georgetown but I don't boondock and I don't have a residential fridge. Good luck. But As I said early on one or both of your batteries may be sulfated. They may reach a full charge level but will not hold it. Or they may never reach full charge levels. My batteries read 13.1 at full charge then drop to 12.9 within hours and then hold at that 12.9 indefinitely until a load is applied without a charger attached. You can detach both batteries from each other while still in the coach and charge and test them separately if you want to. It is easier that lifting them out. Once again, they will decline fairly rapidly even if they are disconnected if they are sulfated. You may hear lots of opinions on what type of replacement batteries to buy. My personal choice is AGM, second choice sealed lead acid and last choice unsealed lead acid. All lead acid batteries can sulfate. And all unsealed batteries require regular fluid checks. True marine deep cycle batteries are more expensive but have much more discharge capacity if you boondock or have a residential fridge. And sealed of any type are basically maintenance free.

[Schvarak]

Originally Posted by BillMFl

The best way for you to deal with your batteries for sure now is to pull both out and charge them overnight. Use your volt meter on each battery separately. Immediately after full charge they should read 13.1 volts minimum depending on the charge rate of your charger. Most chargers have a bulk rate of 13.5 to 14 volts that then drop down to 13.1 maintanance rate. A fully charged battery will hold that 13.1 for awhile but eventually drop to 12,7 to 12.9 which it will then hold as fully charged if the battery is ok. If the battery is sulfated it will not hold at 12,7 but will keep dropping even without any attached drain! One or both of your batteries could be damaged by sulfation and you need to separate them to know for sure. While they are out and separated you can take them to a Sam's Club for a free load test. Other shops will likely do it for free too since they know you might need to buy new batteries and they hope you will buy from them after the test. Last summer I bought two AGM sealed glass mat batteries from Sam's club. They cost about $120 each. They use fiberglass mat instead of lead plates and can withstand deep discharge and recover way better than lead acid batteries. And because they are sealed you don't have to worry about adding water. I used similar but larger AGMs in my 43' Trawler and they last much longer than lead acid batteries and can survive multiple deep discharging that would destroy lead acid batteries. The AGMs at Sam's are a bargain and have plenty of capacity unless you boondock a lot in which case you would want Group 29 or 31 sized batteries for more amp hour capacity. The Sam's AGMs are working fine in my 37' Georgetown but I don't boondock and I don't have a residential fridge. Good luck. But As I said early on one or both of your batteries may be sulfated. They may reach a full charge level but will not hold it. Or they may never reach full charge levels. My batteries read 13.1 at full charge then drop to 12.9 within hours and then hold at that 12.9 indefinitely until a load is applied without a charger attached. You can detach both batteries from each other while still in the coach and charge and test them separately if you want to. It is easier that lifting them out. Once again, they will decline fairly rapidly even if they are disconnected if they are sulfated. You may hear lots of opinions on what type of replacement batteries to buy. My personal choice is AGM, second choice sealed lead acid and last choice unsealed lead acid. All lead acid batteries can sulfate. And all unsealed batteries require regular fluid checks. True marine deep cycle batteries are more expensive but have much more discharge capacity if you boondock or have a residential fridge. And sealed of any type are basically maintenance free.

I bought 2 Interstate 27DC batteries at Costco yesterday $80 per and installing them today. I will also be installing the quickfill battery watering system. The $4.00 disconnect switch i bought at harbor freight should help keep parasitic discharge minimal when my rig is in storage.

[Schvarak]

Originally Posted by Schvarak

I bought 2 Interstate 27DC batteries at Costco yesterday $80 per and installing them today. I will also be installing the quickfill battery watering system. The $4.00 disconnect switch i bought at harbor freight should help keep parasitic discharge minimal when my rig is in storage.

Here's the end result. PERFECT!@