Help me figure out a problem with my house batteries

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ProCycle
Posts: 135
Joined: Sat Oct 03, 2020 1:28 pm

Help me figure out a problem with my house batteries

Post by ProCycle »

I arrived at my boondocking spot on Tuesday afternoon. That evening the inverter would not power on. After a little investigation I found the house batteries were down to 11.2 volts. Of course the generator would not start either. Highly inconvenient! This was unexpected as I keep the coach connected to shore power when parked at home. I periodically check the voltage with a Victron battery monitor and it is always good. It checked out OK Tuesday morning before leaving home.

I ended up running idling the coach engine for about half an hour which put enough charge into the house batteries to start the generator. I ran the generator for an hour or so which brought the house battery voltage back up to 13+ volts. I didn't use any power over night except for a few minutes of LED lights. First thing in the morning the house batteries were down to 10.9 volts. Once the sun was up the solar started to slowly bring the voltage up but was still not enough to start the generator on Wednesday night.

Again, I ran the coach engine long enough to start the generator and then ran the generator all night so I could also run the furnace. I didn't have enough propane to do that for another night so I came home. Figuring that I have a failed battery I've removed them from the coach but they all test out good with a volt meter. These are gigantic 800AH Lifeline 6V batteries. All 4 measure 6.51v-6.45v. Today I will take them to my local battery shop and have them load tested. Other than this incident I've never discharged them more than 30%.

Assuming my batteries load test good does anybody have an idea what happened?

It seems like the house batteries either weren't charged in spite of being on shore power and showing 14+ volts Tuesday morning or they fully discharged while I was driving 80 miles to the camp spot.

My system in addition to the batteries: Magnum 2800 watt inverter/charger, 840 watts solar with Morningstar controller, Victron shunt type battery monitor.
Jeff
1997 Ivory Edition 3740 Cat 3126 Allison
ProCycle
Posts: 135
Joined: Sat Oct 03, 2020 1:28 pm

Re: Help me figure out a problem with my house batteries

Post by ProCycle »

They all failed the load test... I've got a new set to install today.
Jeff
1997 Ivory Edition 3740 Cat 3126 Allison
Moonwink
Posts: 50
Joined: Sun Oct 27, 2019 7:46 pm
Location: Near St Louis, MO

Re: Help me figure out a problem with my house batteries

Post by Moonwink »

Coldest night I ever spent my one of my previous MHs was in Yellowstone NP in late June the year after the fires. On the trip there from StL, we spent every night in a campground connected to shorepower - no problems. There were no hookups available in Yellowstone. No sooner than the sun started to set and the temperature dropped, I flipped on the thermostat and heard the blower start to spin up but before reaching full speed, it started to slowdown. The house battery was bad! Fine time to find out - about 9pm inside a NP with no stores anywhere close. Generators aren't permitted after dark. It was summertime and we hadn't brought heavy blankets. It was a miserable night to say the least and we were all up before sunrise to get going for the next so the engine heater could warm us up. That was a long time ago but it's never happened to me again. Lesson learned.
Don Ford
2004 Safari Trek 31SBD (F53/V10 20,500GVW)
'15 Malibu 2LT or '97 Aerostar MiniVan (Remco driveshaft disconnect) for Towed vehicles
BlueOx Aventa II Towbar - ReadyBrake Inertia Brake System
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Help me figure out a problem with my house batteries

Post by TDJohn »

ProCycle wrote: Fri Oct 07, 2022 11:48 am I arrived at my boondocking spot on Tuesday afternoon. That evening the inverter would not power on. After a little investigation I found the house batteries were down to 11.2 volts. Of course the generator would not start either. Highly inconvenient! This was unexpected as I keep the coach connected to shore power when parked at home. I periodically check the voltage with a Victron battery monitor and it is always good. It checked out OK Tuesday morning before leaving home.

I ended up running idling the coach engine for about half an hour which put enough charge into the house batteries to start the generator. I ran the generator for an hour or so which brought the house battery voltage back up to 13+ volts. I didn't use any power over night except for a few minutes of LED lights. First thing in the morning the house batteries were down to 10.9 volts. Once the sun was up the solar started to slowly bring the voltage up but was still not enough to start the generator on Wednesday night.

Again, I ran the coach engine long enough to start the generator and then ran the generator all night so I could also run the furnace. I didn't have enough propane to do that for another night so I came home. Figuring that I have a failed battery I've removed them from the coach but they all test out good with a volt meter. These are gigantic 800AH Lifeline 6V batteries. All 4 measure 6.51v-6.45v. Today I will take them to my local battery shop and have them load tested. Other than this incident I've never discharged them more than 30%.

Assuming my batteries load test good does anybody have an idea what happened?

It seems like the house batteries either weren't charged in spite of being on shore power and showing 14+ volts Tuesday morning or they fully discharged while I was driving 80 miles to the camp spot.

My system in addition to the batteries: Magnum 2800 watt inverter/charger, 840 watts solar with Morningstar controller, Victron shunt type battery monitor.
When you were not able to start your generator, did you try using the boost switch to get the generator going?
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
ProCycle
Posts: 135
Joined: Sat Oct 03, 2020 1:28 pm

Re: Help me figure out a problem with my house batteries

Post by ProCycle »

TDJohn wrote: Tue Dec 20, 2022 2:37 am When you were not able to start your generator, did you try using the boost switch to get the generator going?
I did not. I was working by myself. But it doesn't matter, my old batteries had lost most of their capacity. New replacements are doing great.
Jeff
1997 Ivory Edition 3740 Cat 3126 Allison
eneriksen
Posts: 21
Joined: Sun May 14, 2023 3:55 pm

Re: Help me figure out a problem with my house batteries

Post by eneriksen »

Note that with larger inverters, mine is 4KW, there is a ghost drain that can run the lithium battery down to its BMS cutoff voltage during the night, even with no load. I always put mine in sleep mode when I go to bed. While I have enough solar to run my refrigerator, and some AC, during the day, I currently only have room for 100AH of battery.

I don't know how your chassis isolator is configured but on my just starting the engine allows me to immediately start my generator. Is it possible that your lithium battery BMS has reached its low voltage disconnect voltage.
canucklehead
Posts: 7
Joined: Wed May 31, 2023 7:47 pm

Re: Help me figure out a problem with my house batteries

Post by canucklehead »

I find leaving plugged in can drain juice out of batteries, keep an on water level. i add distilled water. Shocking how much water you can add if never checked.
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