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keigm

New Coach dead batteries

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Just picked up our 2019 all electric Newmar London Aire and left town for a 2 week cruise.  Prior to going I purchased a Schumacher charger/tender (15amp/3amp) and set it for AGM to keep our 8 AGM batteries at charge.  It was in the maintenance phase prior to leaving but completely dead on return.  I got it moved to a 30 amp plug in spot and after approximately 16 hours it was only at 62%.  I will go back and check on it in a few hours and put it back inside and re hook it up to the Schumacher charger/tender to see if it will maintain it.  

     What happened was the owner of the community storage unplugged it and did not reset it to AGM and all the batteries went dead even though I had all the breakers off and the battery disconnect disconnected too.  I wonder how much damage was done to the batteries and if they should be de-sulfated and if so how do you do it. 

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Assuming the "default setting" for the Schumacher charger is WET CELL, that is close enough to the charge parameter of the AGM that this would NOT be the cause of the battery issue.

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I'd be curious to learn what was drawing on the batteries despite your having disconnected them. Two weeks is awfully quick for batteries to go dead on their own.

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I have no idea what could be drawing it down.  Thanks for the input.  There is a house kill switch but obviously doesn’t kill everything.

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I faced the same issue with a New Aire that I had to store for two months in a barn with no power.  Even with the battery disconnect switches turned off, there is still a draw on the batteries from all of the residual electronics in the coach that are still powered on.  The only way to store the coach without having power is to physically disconnect the leads from the batteries terminals, both for the house and chassis.  I did that and after 2 months the batteries were still at 12.6 volts when I returened.  AGM batteries store very well with no load on them.  A concern I had was what would the electronics do after the power was restored.  I found that they all fired up perfectly with no memory loss for any of the setting that I had changed prior to the disconnect.  If you didn't want to go through the trouble of disconnecting the batteries and had reliable power for a small battery charger, I would think an alternative would be to plug the coach into that power using a 15 amp adapter and set your coach imput on the Silver Leaf down to 15 amps.  That should allow you to maintain the charge on all batteries with everything shut off.  If there is a Wi-Fi available, you could monitor the battery status on the coach with Rozie.  You would have to have someone available to re-store the electric connection in the event of a power failure.  If no one was available to do that it would not do you a lot of good to monitor the coach and just be able to watch the batteries die.  Safest bet is to disconnect the batteries; four nuts on the house side and two on the chassis, less than 20 minutues time.           

 

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Two thoughts...

The Schumacher chargers can sometimes be pretty basic units. The output in maintenance mode may only be a few amps, but it's the voltage output level that's most important as too high of a voltage for long-term storage can damage batteries. Why not just use the on-board battery charging system? If you only have a 15-amp outlet available where you store the coach, you can plug in with an adapter and then program your battery charging system to adjust to the lowered input. The Newmar battery management system has to be more advanced that the Schumacher.

From this thread and the other similar threads, it sounds like some coaches have considerable draw on the house batteries even when the switch is in the 'off' position. Perhaps it would be wise to install a manual battery disconnect switch on the positive lead out of the battery bank for those times when it's desired to fully power the system down, such as when being stored without the ability to keep a charger powered on. Blue Sea makes some high-capacity switches which are very nice - I've got one installed immediately next to our battery bank and it gets used when a full shut-down is necessary.

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54 minutes ago, mikekohut said:

I faced the same issue with a New Aire that I had to store for two months in a barn with no power.  Even with the battery disconnect switches turned off, there is still a draw on the batteries from all of the residual electronics in the coach that are still powered on.  The only way to store the coach without having power is to physically disconnect the leads from the batteries terminals, both for the house and chassis.  I did that and after 2 months the batteries were still at 12.6 volts when I returened.  AGM batteries store very well with no load on them.  A concern I had was what would the electronics do after the power was restored.  I found that they all fired up perfectly with no memory loss for any of the setting that I had changed prior to the disconnect.  If you didn't want to go through the trouble of disconnecting the batteries and had reliable power for a small battery charger, I would think an alternative would be to plug the coach into that power using a 15 amp adapter and set your coach imput on the Silver Leaf down to 15 amps.  That should allow you to maintain the charge on all batteries with everything shut off.  If there is a Wi-Fi available, you could monitor the battery status on the coach with Rozie.  You would have to have someone available to re-store the electric connection in the event of a power failure.  If no one was available to do that it would not do you a lot of good to monitor the coach and just be able to watch the batteries die.  Safest bet is to disconnect the batteries; four nuts on the house side and two on the chassis, less than 20 minutues time.           

 

Thanks.  Turning the Silver Leaf down to 15 (actually 20, since it was a 20 amp switch) is what I did.  I was told it is safer to use a tender so I did that.  The Schumacher charger/tender seems to be turned on by setting up std or AGM.  All seems to work well with power and goes to **** w/o power.  I am not aware of “Rozie” though.  Being able to monitor the batteries would be the ticket.  I bet Rozie is only on the KA and NA.  I have heard of some feature like that and only on those 2 coaches. 

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On 5/11/2019 at 12:29 PM, Keigm said:

Prior to going I purchased a Schumacher charger/tender (15amp/3amp) and set it for AGM to keep our 8 AGM batteries at charge.

Is there any reason why you didn't just plug the coach in since you had power on site where it was parked? I realize it doesn't excuse why it was dead, but I would think the factory equipment would be more robust to keep those batteries maintained while you were away.

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Chances are your inverter killed your batteries. Tiffin has put in a dedicated switch to disconnect the inverter when in storage. Also like someone mentioned, you should have been able to leave the coach plugged in without an additional charger and all should have been fine. Our coach is plugged in for months at a time when parked at home.

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I installed a remote battery switch between out inverter and our battery bank. When we're not using the coach I can disable the inverter from inside the coach. Simple push of the button upstairs, and the remote battery switch reconnects things. The Blue Sea switch is rated for 500A, and it sure saves crawling around down below when I want to turn the inverter on/off.

Just offering this as a possible solution if the inverter is found to be the problem.

https://www.bluesea.com/products/7700/ML-RBS_Remote_Battery_Switch_with_Manual_Control_-_12V_DC_500A

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If the inverter is consuming ANY power when turned off, you need to find out why.

Absolutely, in "standby mode" it DOES use power from the batteries.

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Don't know about any inverter other than ours, but if the physical power button on the inverter itself is in the 'on' position there is a power draw from the batteries. It's what allows the control panel upstairs to be able to communicate with the inverter and remotely control what's going on. According to the manual on my inverter it draws <1 amp in this type of situation. Not enough to be concerned for a short time period, but if I'm leaving the coach for a week or longer there is no need to have it drawing anything from the batteries. The remote battery switch, on the other hand, draws 0 amps during idle times.

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After re reading this I to am wondering why you didn't just plug the coach in as you had power available. The electrical management system in the London Aire is way ahead of the battery minder.

Bill

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I had it plugged in 1st with the silver leaf changed from 30 amps to 20 amps since our plug-in was a 20amp plug.  I was told it was better to use the Schumacher as it was less likely to throw the GFI.  Both systems work when there is power and not when there isn’t.  All the breakers were thrown off with the Schumacher on thinking if power was ever lost the batteries would just sit with no draw.  I learned that wasn’t the case.  Everything is up and going now and all seems to be ok.  Thanks for your expertise.  Learning how best to take care of these new toys is an education.

What seems like to best answer is some sort of remote monitoring system where you can check on it occasionally.

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Keigm

How I maintain my coach batteries is with a small trickle charger. I have it plugged into my block heater outlet. The out let is live only when plugged into shore power or on generator.

I have many grimlins that would draw my coach batteries down. Since mounting the trickle charger no problems. (Lots of folks have heard this before)

Herman 

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