Trickle/ battery maintainer during storage

[MacGyver612]

I have a 2014 Itasca Suncruiser 38Q. What would the best trickle, battery maintainer to get, use on AGM batteries. Went to check on coach and house batteries were dead. Plugged coach in so I could get charged up, Now looking for best way to keep charged during storage.
Come spring I am going to put another shut off switch on house batteries or possibly some kind of latching solenoid, relay. House bank has three ground wires, cables and three positive wires , cables. So the latching idea might be less large cable runs to have switch under entrance step area. Sorry to ramble, the main thing is to get through storage. Thanx in advance of your reply's.

[Persistent]

Storing on shore power
The best maintainer for house batteries is usually the on-board inverter/converter/charger. If you are worried about how it works, just measure battery terminal voltage.
13.2 volts is ideal (My WFCO drops to 13.2 volts after 4 days un-occupied.)
13.6 is maximum for AGM
12.7 is minimum
Fully recharge for 14 hours before voltage drops to 12.4 volts.
Periodically check voltage until you are confident it is working properly.

Storing Disconnected
An alternative is to install a battery shut off switch in the positive to the battery bank. Remove all connections to positive side of battery bank. Connect switch. Re-connect all positive cables to switch.

Fully charge for 14 to 18 hours.
Disconnect
Monitor battery terminal voltage.
Fully recharge for 14 hours before battery voltages drops to 12.4 volts.
Fully recharge for 14 hours when taken out of storage.

Disconnected AGM batteries may stay above 12.4 volts for as much as 12 months. Periodically check voltage until you know how long yours will last.

I recommend checking voltage after one week, one month, and every 3 months thereafter for AGM.

[MacGyver612]

Originally Posted by Persistent

Storing on shore power
The best maintainer for house batteries is usually the on-board inverter/converter/charger. If you are worried about how it works, just measure battery terminal voltage.
13.2 volts is ideal (My WFCO drops to 13.2 volts after 4 days un-occupied.)
13.6 is maximum for AGM
12.7 is minimum
Fully recharge for 14 hours before voltage drops to 12.4 volts.
Periodically check voltage until you are confident it is working properly.

Storing Disconnected
An alternative is to install a battery shut off switch in the positive to the battery bank. Remove all connections to positive side of battery bank. Connect switch. Re-connect all positive cables to switch.

Fully charge for 14 to 18 hours.
Disconnect
Monitor battery terminal voltage.
Fully recharge for 14 hours before battery voltages drops to 12.4 volts.
Fully recharge for 14 hours when taken out of storage.

Disconnected AGM batteries may stay above 12.4 volts for as much as 12 months. Periodically check voltage until you know how long yours will last.

I recommend checking voltage after one week, one month, and every 3 months thereafter for AGM.

Might leave coach plugged in, but place I store said ok for 1 amp trickle. don't want draw too much for on board unit. I set invert charger to 15 amp supply, I suppose could see what it might do on 5 amp for supply? Have heard of some saying they have had over charge and or boiling problems?

[Winemaker2]

I have used Battery Minders for many years and have been very pleased with results. Their tech support has been helpful & informative.
I use a small 1.5A unit for chassis battys
https://www.batteryminders.com/1510-...-with-warranty

I thought with 8 - 6V house bank Id go with their larger selectable 2-4-8A unit
https://www.batterymart.com/p-128cec...YaAhQ8EALw_wcB

I have a chassis disconnect Sw but only the disconnect relay on the house. I considered adding a disconnect to the house but have not had any issues with the maintainer and only the relay. I have mounted both semi permanently in the MH and wired them together.. I thus have one cord to connect while in storage to power up both. I used the ring terminals on the battys and can simply disconnect the leads from the maintainer when not needed / desired.
Many recommend just plugging in the MH and using the on board charger. Im in the minority that can't see using an expensive, high amp capable inverter/charger 24/7 when a simple maintainer works. Neither approach right or wrong... just different!
Agree with MacGyver as my storage location doesn't charge me for power with only maintainers plugged in... extra $ for plugging in MH.

[wolfe10]

If your smart inverter/charger is properly programmed, leave it plugged in 24/7/365.


Set your power share/power save to 5 amps. 5 amps of 120 VAC will give you right at 50 amps of charging for your batteries.


And, as I hope your storage facility manager knows, once the batteries are up to full charge, they take next to nothing to keep them that way. Would not matter what max amp you set it for.


The other question is whether your coach charges both battery banks from the inverter/charger. If not, plenty of good "work arounds".

[Persistent]

All good advice above.

A 1 amp 120 volt charger would be 120 watts.
At 12 volts 120 watts would be 10 amps at 12 volts DC.
Your converter charger will draw next to nothing after your batteries are charged.
Your propane detector may draw another 0.5 amps at 12 volts or 0.05 amps at 120 volts.
Make sure everything else is "off". Inverter "off". Switch off all 120 volt circuit breakers for water heater, house outlets, microwave, etc. Leave converter/charger circuit breaker "on".

"Boiling" batteries are caused by either defective batteries or high charger voltage. If battery terminal voltage is above 13.6 volts, water consumption goes up.

Some people miss-program their chargers to produce high voltage like 14.4 or 15 volts. This will consume a lot of water and batteries may appear to boil.

Many old portable automotive battery chargers produce 15.0 volts. They should never be left unattended and never be connected for longer than necessary to restart a system.

Measure terminal voltage. If it stays above 13.6, then you need a battery minder. 13.2 is optimum. Batteries will not "boil" at 13.2 volts.

[MacGyver612]

Originally Posted by wolfe10

If your smart inverter/charger is properly programmed, leave it plugged in 24/7/365.


Set your power share/power save to 5 amps. 5 amps of 120 VAC will give you right at 50 amps of charging for your batteries.


And, as I hope your storage facility manager knows, once the batteries are up to full charge, they take next to nothing to keep them that way. Would not matter what max amp you set it for.


The other question is whether your coach charges both battery banks from the inverter/charger. If not, plenty of good "work arounds".

Yes to charges both. Have set to 5 amp power supply. My just let coach charge and float till get battery minder.I was surprised that house batteries went almost no power in such a short amount of time. Have had idle before for same amount of time in past.
Thanx

[MacGyver612]

Originally Posted by Winemaker2

I have used Battery Minders for many years and have been very pleased with results. Their tech support has been helpful & informative.
I use a small 1.5A unit for chassis battys
https://www.batteryminders.com/1510-...-with-warranty

I thought with 8 - 6V house bank Id go with their larger selectable 2-4-8A unit
https://www.batterymart.com/p-128cec...YaAhQ8EALw_wcB

I have a chassis disconnect Sw but only the disconnect relay on the house. I considered adding a disconnect to the house but have not had any issues with the maintainer and only the relay. I have mounted both semi permanently in the MH and wired them together.. I thus have one cord to connect while in storage to power up both. I used the ring terminals on the battys and can simply disconnect the leads from the maintainer when not needed / desired.
Many recommend just plugging in the MH and using the on board charger. Im in the minority that can't see using an expensive, high amp capable inverter/charger 24/7 when a simple maintainer works. Neither approach right or wrong... just different!
Agree with MacGyver as my storage location doesn't charge me for power with only maintainers plugged in... extra $ for plugging in MH.

Looking to let coach get to full charge float and then put on a battery minder. Better than having inverter charge going bad.
Thanx

[Winemaker2]

Originally Posted by MacGyver612

Looking to let coach get to full charge float and then put on a battery minder. Better than having inverter charge going bad.
Thanx

Thats exactly what I do most of the time. I have 30A power available at home but not at storage location. The nice part of the 2-4-8A unit I have on the house is if I dont get the house bank all the way to 100% SOC it has the capacity to do it before going into the maintenance mode. A 1.5A unit on a 8 - 6V GC bank would struggle trying to do much more than maintain.
They are more $ but I felt worth the premium to protect the batty investment.

[xc-mark]

Originally Posted by Winemaker2

Thats exactly what I do most of the time. I have 30A power available at home but not at storage location. The nice part of the 2-4-8A unit I have on the house is if I dont get the house bank all the way to 100% SOC it has the capacity to do it before going into the maintenance mode. A 1.5A unit on a 8 - 6V GC bank would struggle trying to do much more than maintain.
They are more $ but I felt worth the premium to protect the batty investment.

You really need to know how many amp hours battery total connected to the charge! Batteryminder 1.5amp really could only keep 1 -70 amp hour 12 voltat full charge. The Noco genius 10 is ok for 200 amp hours and can be set to 6 or 12 volt , flooded , AGM and Lithium. It holds the setting in the event of a power failer. going past 200 amp hours get into a charger that is something like a victron IP-22 smart charger 25 amps. If you have a big battery bank with a smaller charger it never gets for full charge then steps back to float. I have 540 amp hours of coach battery and I though I could get by with the Noco 10 , it has a hard time getting past bulk charge 14.4volts to step back to 13.4 volts with my AGM. They rate it at 200 amp hour banks , I think it would be fine a little over that but not more then double. Its a nice compact universal charger so I got one, Now I am rethinking and getting the Victron smart 25 amp unit. dont get me wrong the Noco is a good unit and will suit your needs if your around 200 amp hour or smaller. some points to look for in a charger , Temp compensation , battery type , ability to charge deep discharge battery or at zero volts.


https://www.amazon.com/NOCO-GENIUS10.../dp/B07W3QT226

[Winemaker2]

Originally Posted by xc-mark

You really need to know how many amp hours battery total connected to the charge! Batteryminder 1.5amp really could only keep 1 -70 amp hour 12 voltat full charge. The Noco genius 10 is ok for 200 amp hours and can be set to 6 or 12 volt , flooded , AGM and Lithium. It holds the setting in the event of a power failer. going past 200 amp hours get into a charger that is something like a victron IP-22 smart charger 25 amps. If you have a big battery bank with a smaller charger it never gets for full charge then steps back to float. I have 540 amp hours of coach battery and I though I could get by with the Noco 10 , it has a hard time getting past bulk charge 14.4volts to step back to 13.4 volts with my AGM. They rate it at 200 amp hour banks , I think it would be fine a little over that but not more then double. Its a nice compact universal charger so I got one, Now I am rethinking and getting the Victron smart 25 amp unit. dont get me wrong the Noco is a good unit and will suit your needs if your around 200 amp hour or smaller. some points to look for in a charger , Temp compensation , battery type , ability to charge deep discharge battery or at zero volts.





https://www.amazon.com/NOCO-GENIUS10.../dp/B07W3QT226

Larger amp chargers are good to bring a larger batty bank up from a low SOC but I dont think they are necessary to get a batty to or close to 100% SOC. The closer you get to 100% the lower the amps reqd but the longer the time. Just watch the charger and the amps decrease significantly as you approach full charge.

If you suspect or know from a monitor that you have not reached 100% just turn the charger off and back on and it will cycle through the bulk and absorption phase before switching to float or maintain. The phase times will be shorter but the batty SOC will be increased. I've done this several times with a boat house bank that has a Balmar smart gauge monitor and I can see the SOC increase with each time I cycle the charger.
This is especially important when I store the boat without access to power. I charge to 100% SOC and disconnect battys.

[wolfe10]

Originally Posted by MacGyver612

Yes to charges both. Have set to 5 amp power supply. My just let coach charge and float till get battery minder.I was surprised that house batteries went almost no power in such a short amount of time. Have had idle before for same amount of time in past.
Thanx

Still not sure why you want to buy a separate battery minder rather than let your properly programmed smart inverter/charger do it.

[MacGyver612]

Originally Posted by xc-mark

You really need to know how many amp hours battery total connected to the charge! Batteryminder 1.5amp really could only keep 1 -70 amp hour 12 voltat full charge. The Noco genius 10 is ok for 200 amp hours and can be set to 6 or 12 volt , flooded , AGM and Lithium. It holds the setting in the event of a power failer. going past 200 amp hours get into a charger that is something like a victron IP-22 smart charger 25 amps. If you have a big battery bank with a smaller charger it never gets for full charge then steps back to float. I have 540 amp hours of coach battery and I though I could get by with the Noco 10 , it has a hard time getting past bulk charge 14.4volts to step back to 13.4 volts with my AGM. They rate it at 200 amp hour banks , I think it would be fine a little over that but not more then double. Its a nice compact universal charger so I got one, Now I am rethinking and getting the Victron smart 25 amp unit. dont get me wrong the Noco is a good unit and will suit your needs if your around 200 amp hour or smaller. some points to look for in a charger , Temp compensation , battery type , ability to charge deep discharge battery or at zero volts.





https://www.amazon.com/NOCO-GENIUS10.../dp/B07W3QT226

I replaced 4 12v AGM with 8 6v gc2 hd AGM 210ah, with a total of 840ah.

[MacGyver612]

Originally Posted by wolfe10

Still not sure why you want to buy a separate battery minder rather than let your properly programmed smart inverter/charger do it.

Cheaper to replace battery minders than inverter charger. Still on the fence.....