Battery Drain

Revk · 05-13-2022, 03:03 PM

We own a 2017 Thor Axis and are having an issue with the chassis battery draining overnight. This battery was purchased and installed in March of this year. We can't find anything we left on that would drain the battery but we are wondering if someone may know of an obscure light or switch we may have overlooked. Our next step is to remove the battery (a pain to do) and have it checked but if the battery is fine we are not sure where to look next.

Grumpy Grampa · 05-13-2022, 08:08 PM

Sounds like a bad battery. Have you had it checked?

lwmcguir · 05-13-2022, 08:12 PM

Check out your battery management system

It should be charging both house and chassis batteries

Shreck · 05-13-2022, 09:25 PM

While we are on the subject I have a new to me freedom elite 23H I had it plugged into a 30 amp SP when I left Monday and everything was working fine on the 12 volt side before I plugged it in, I came home today and the batteries are completely dead. Is there a certain way the battery switch has to be in?

**16ACE27** · 05-13-2022, 10:21 PM

Quote:

Originally Posted by Shreck

While we are on the subject I have a new to me freedom elite 23H I had it plugged into a 30 amp SP when I left Monday and everything was working fine on the 12 volt side before I plugged it in, I came home today and the batteries are completely dead. Is there a certain way the battery switch has to be in?

As mentioned about 15,000 times in this forum alone, the battery disconnect has to be shut (ON, USE/STORE in USE) for the converter to charge the house batteries.

Lt Keefer · 05-13-2022, 11:06 PM

Chassis battery you say? Do you have heated mirrors and are they turned on?

Shreck · 05-13-2022, 11:28 PM

Quote:

Originally Posted by 16ACE27

As mentioned about 15,000 times in this forum alone, the battery disconnect has to be shut (ON, USE/STORE in USE) for the converter to charge the house batteries.

Mine also has a what appears to be a toggle switch that shows the voltage on 12 volt one way and SP when thrown the other way. Does it make a difference which way it is thrown for the house batteries to charge?

**16ACE27** · 05-14-2022, 12:21 AM

Quote:

Originally Posted by Shreck

Mine also has a what appears to be a toggle switch that shows the voltage on 12 volt one way and SP when thrown the other way. Does it make a difference which way it is thrown for the house batteries to charge?

Sounds like a previous owner mod for voltage monitoring. If that is the case it shouldn't effect charging, BUT, you'll never know for sure without tracing the wiring.

ScottyB410 · 05-14-2022, 12:36 AM

Quote:

Originally Posted by Revk

We own a 2017 Thor Axis and are having an issue with the chassis battery draining overnight. This battery was purchased and installed in March of this year. We can't find anything we left on that would drain the battery but we are wondering if someone may know of an obscure light or switch we may have overlooked. Our next step is to remove the battery (a pain to do) and have it checked but if the battery is fine we are not sure where to look next.

Hi there.
Do you have an On/Off switch between the battery and the coach. If not, something is ALWAYS connected. If you do, turn it off. Go to bed, wake up and turn it on. if it is charged, your answer is some sort of parasitic drain somewhere - 99% of the time this is the issue.

BASSMAN · 05-18-2022, 10:25 PM

A bad diode bridge in your alternator can drain your battery, it will allow the battery to keep the windings in the alternator energized an will drain the battery, let it set over night after charging it up and then put your hand on the alternator in the morning, if its warm you got a bad alternator, that is if you can get your hand in to feel it

Edki45 · 05-18-2022, 11:21 PM

Quote:

Originally Posted by Revk

We own a 2017 Thor Axis and are having an issue with the chassis battery draining overnight. This battery was purchased and installed in March of this year. We can't find anything we left on that would drain the battery but we are wondering if someone may know of an obscure light or switch we may have overlooked. Our next step is to remove the battery (a pain to do) and have it checked but if the battery is fine we are not sure where to look next.

Check it with a hydrometer after battery has cooled off between charge cycles.
A weak or dead cell will discharge the battery whether connected or not. I have 59 years professional experience with batteries and vehicles of all kinds.

Chateau_Nomad · 05-19-2022, 12:11 AM

Quote:

Originally Posted by Edki45

Check it with a hydrometer after battery has cooled off between charge cycles.
A weak or dead cell will discharge the battery whether connected or not. I have 59 years professional experience with batteries and vehicles of all kinds.

I also use a hydrometer to check my 6volt GC2 batteries... however many folks have maintenance free "sealed" batteries. They must be properly load tested to check their health.

simidrm · 05-19-2022, 12:19 AM

You can also check that diode with a ohm meter by unhooking the battery and use a ohm meter from the charge cable to ground and if you get no reading then the diode is good

**16ACE27** · 05-19-2022, 12:23 AM

Quote:

Originally Posted by simidrm

You can also check that diode with a ohm meter by unhooking the battery and use a ohm meter from the charge cable to ground and if you get no reading then the diode is good

Depending on polarity and ohmmeter range.

txc2936@yahoo.com · 06-02-2022, 12:08 AM

ACE, I think i was number 7000 on this issue, I decided to see if THOR updated owners manual, and they have... However, they are indicating the switch needs to be in ON position for Solar Panel to charge batteries. I think you had indicated the Solar Panels bypass the switch?

I find that my panel shows FULL when entering the RV, so i think the charge is always on the batteries. I shut off battery switch when leaving RV for a few days.

I decided to check revision. Manual Revised in Jan 22.

**16ACE27** · 06-02-2022, 01:13 AM

Quote:

Originally Posted by txc2936@yahoo.com

ACE, I think i was number 7000 on this issue, I decided to see if THOR updated owners manual, and they have... However, they are indicating the switch needs to be in ON position for Solar Panel to charge batteries. I think you had indicated the Solar Panels bypass the switch?

I find that my panel shows FULL when entering the RV, so i think the charge is always on the batteries. I shut off battery switch when leaving RV for a few days.

I decided to check revision. Manual Revised in Jan 22.

It has been my experience that the solar charge controller is connected directly to the house (AUX) batteries. So they always charged without regard to the condition of the battery disconnect switch.

BUT, you can never be sure unless you do some extended voltage testing or trace out the wires from the solar charge controller to their connection to the 12 VDC system.

Chateau_Nomad · 06-02-2022, 01:14 AM

Quote:

Originally Posted by txc2936@yahoo.com

ACE, I think i was number 7000 on this issue, I decided to see if THOR updated owners manual, and they have... However, they are indicating the switch needs to be in ON position for Solar Panel to charge batteries. I think you had indicated the Solar Panels bypass the switch?

I find that my panel shows FULL when entering the RV, so i think the charge is always on the batteries. I shut off battery switch when leaving RV for a few days.

I decided to check revision. Manual Revised in Jan 22.

When I added my roof solar panels, part of the plan was to have the batteries continuously charged... ESPECIALLY when stored over the winter. My charge controller is connected directly to the batteries, NOT to the disconnect (use/store) switch.

I don't understand Thor's thinking here. Wouldn't a separate solar disconnect switch be better?

**16ACE27** · 06-02-2022, 01:28 AM

Quote:

Originally Posted by Chateau_Nomad

When I added my roof solar panels, part of the plan was to have the batteries continuously charged... ESPECIALLY when stored over the winter. My charge controller is connected directly to the batteries, NOT to the disconnect (use/store) switch.

I don't understand Thor's thinking here. Wouldn't a separate solar disconnect switch be better?

Or turn off the controller?

BASSMAN · 06-02-2022, 01:35 AM

I did my own install of 4, 100 watt solar panels and 4 gel cell batteries an all from Renogy, I store my coach during the summer months and only use it during the fall, winter and spring along the Colorado River, Renogy told me to just pull the fuse between the controller and the inverter when the coach is stored and to re install an hook up and charge the batteries from shore power once a month when being stored, so far it has worked for me.

Chateau_Nomad · 06-02-2022, 01:57 AM

Quote:

Originally Posted by 16ACE27

Or turn off the controller?

Charge controllers generally don't have ON/OFF switches; the install should have a separate properly rated disconnect switch on the positive cable between the panels and charge controller. Then there should be a properly rated fuse (breaker) between the controller and batteries.

Provided you have sky exposure, the nice thing about roof solar is not having to plug in during storage - never worrying about the batteries being fully charged. The whole point of having the battery disconnect switch (use/store) OFF with batteries completely disconnected from the coach is to prevent any drain from the coach... BUT you still want the panels to charge the batteries.

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