Reliable battery system issues

[Maxwell1121]

I have a 2023 Thor tellaro 20j. 6 weeks old. Struggling to understand the coach battery system. It seems she the ambient temp outside is approx 100 degrees or above is when the real trouble starts. I travel non stop with 6 kids. This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor. 1 at master Volt 1 at Reliable battery. Nobody has a clue what’s going on and they have been pretty honest. They don’t really know anything more about these systems than what I have read in the manual. 1 guy at Thor thought it might be the overloads for the alternator and battery swapped. But I can’t find those connectors as he described.
5)this just started today. BALMAR display , *no service available for this selected device*

[fourthgear]

What size of LI battery system & what Inverter do you have & do you have the second 280 amp Alternator for charging the batteries when engine is on ?

[Maxwell1121]

Originally Posted by fourthgear

What size of LI battery system & what Inverter do you have & do you have the second 280 amp Alternator for charging the batteries when engine is on ?

(2) 100 amp
Yes 280 amp

[DavidEM]

I suspect the large load of the inverter powering the rear A/C is dropping the voltage to the point that the inverter eventually drops out, shutting down the A/C. That large load will also artificially show low or zero SOC if it is based on voltage.

What is your rear A/C? Even a 9,000 btu unit will draw 10 amps at 120V which is as much as 120 amps DC into the inverter. The wiring may not be able to handle that much current without creating a significant voltage drop which also contributes to shutting down the inverter.

It takes a very robust DC system to run a rear A/C from an inverter while supplying the current from the chassis alternator.

David

[Bill Johnson]

Originally Posted by Maxwell1121

I have a 2023 Thor tellaro 20j. 6 weeks old. Struggling to understand the coach battery system. It seems she the ambient temp outside is approx 100 degrees or above is when the real trouble starts. I travel non stop with 6 kids. This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor. 1 at master Volt 1 at Reliable battery. Nobody has a clue what’s going on and they have been pretty honest. They don’t really know anything more about these systems than what I have read in the manual. 1 guy at Thor thought it might be the overloads for the alternator and battery swapped. But I can’t find those connectors as he described.
5)this just started today. BALMAR display , *no service available for this selected device*

Many new people on here that have the lithium system instead of a generator are have problems with a large load on the system. I wouldn't be surprised if they get rid of the lithium system or greatly enlarge it.might need to put a regular generator in the camper or go for a different motorhome. I bet they will tell you it's normal

[Chance]

Originally Posted by Maxwell1121

......cut.....
This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor.

.....cut....

The very first thing I would do in troubleshooting is determine what is actually happening.

The batteries should not go from 85% SOC to 0 SOC in 15 minutes solely due to air conditioner load when engine is running. That part doesn’t make sense, not even at engine idle because alternator should assist some, and even if it didn’t, 85% of 200 Ah should last longer than 15 minutes.

I would test while idling at a stop by watching SOC to see if it gradually drops from 85% to 60% to 40% etc. until system shuts off. Or is it more of a sudden shutdown where everything shuts off when batteries still had charge? That would be my guess.

I expect you’re not actually draining the batteries completely down, but rather they are shutting down due to BMS (battery management system) to protect them from excessive current or heat. Just an educated wild guess on my part.

If BMS shuts off battery(íes), you may see 0% SOC depending on how things are wired even if the cells still have charge. One thing you did not mention is how you got system running again?

For example, how long does it take to come back on and power air conditioner? And when it does, what is the indicated SOC? Also, do you have to drive a long time with A/C off to build SOC back up to 85%?

Again, I would focus on first determining whether it’s a battery capacity issue or one caused by over-current or excessive heat tripping BMS; or possibly tripping inverter like David suggested, though I don’t see how that would lead to 0% SOC indication.

[Scubawise]

Originally Posted by DavidEM

I suspect the large load of the inverter powering the rear A/C is dropping the voltage to the point that the inverter eventually drops out, shutting down the A/C. That large load will also artificially show low or zero SOC if it is based on voltage.

What is your rear A/C? Even a 9,000 btu unit will draw 10 amps at 120V which is as much as 120 amps DC into the inverter. The wiring may not be able to handle that much current without creating a significant voltage drop which also contributes to shutting down the inverter.

It takes a very robust DC system to run a rear A/C from an inverter while supplying the current from the chassis alternator.

David

This could be it. When we wanted the inverter hooked to AC, OUR 30 year tech and his son an electrician said something like this would happen.

They suggested always rub the generator while driving for AC. IF no AC our inverter powers everything else

[Scubawise]

Originally Posted by Chance

The very first thing I would do in troubleshooting is determine what is actually happening.

The batteries should not go from 85% SOC to 0 SOC in 15 minutes solely due to air conditioner load when engine is running. That part doesn’t make sense, not even at engine idle because alternator should assist some, and even if it didn’t, 85% of 200 Ah should last longer than 15 minutes.

I would test while idling at a stop by watching SOC to see if it gradually drops from 85% to 60% to 40% etc. until system shuts off. Or is it more of a sudden shutdown where everything shuts off when batteries still had charge? That would be my guess.

I expect you’re not actually draining the batteries completely down, but rather they are shutting down due to BMS (battery management system) to protect them from excessive current or heat. Just an educated wild guess on my part.

If BMS shuts off battery(íes), you may see 0% SOC depending on how things are wired even if the cells still have charge. One thing you did not mention is how you got system running again?

For example, how long does it take to come back on and power air conditioner? And when it does, what is the indicated SOC? Also, do you have to drive a long time with A/C off to build SOC back up to 85%?

Again, I would focus on first determining whether it’s a battery capacity issue or one caused by over-current or excessive heat tripping BMS; or possibly tripping inverter like David suggested, though I don’t see how that would lead to 0% SOC indication.

I think our inverter paperwork shows if batteries detected at 10.9 or below shutdown inverter..

[Bill Johnson]

Originally Posted by Maxwell1121

I have a 2023 Thor tellaro 20j. 6 weeks old. Struggling to understand the coach battery system. It seems she the ambient temp outside is approx 100 degrees or above is when the real trouble starts. I travel non stop with 6 kids. This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor. 1 at master Volt 1 at Reliable battery. Nobody has a clue what’s going on and they have been pretty honest. They don’t really know anything more about these systems than what I have read in the manual. 1 guy at Thor thought it might be the overloads for the alternator and battery swapped. But I can’t find those connectors as he described.
5)this just started today. BALMAR display , *no service available for this selected device*

Check this out. This also doesn't take in account the LOSS with the inverter

[Bill Johnson]

Originally Posted by Maxwell1121

I have a 2023 Thor tellaro 20j. 6 weeks old. Struggling to understand the coach battery system. It seems she the ambient temp outside is approx 100 degrees or above is when the real trouble starts. I travel non stop with 6 kids. This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor. 1 at master Volt 1 at Reliable battery. Nobody has a clue what’s going on and they have been pretty honest. They don’t really know anything more about these systems than what I have read in the manual. 1 guy at Thor thought it might be the overloads for the alternator and battery swapped. But I can’t find those connectors as he described.
5)this just started today. BALMAR display , *no service available for this selected device*

What about extending the the front AC to the rear like Limo's do, that way it might cool the back while you drive. The inverter AC could be used just intermittently so as not to use up all the battery capacity

[Scubawise]

Originally Posted by Maxwell1121

I have a 2023 Thor tellaro 20j. 6 weeks old. Struggling to understand the coach battery system. It seems she the ambient temp outside is approx 100 degrees or above is when the real trouble starts. I travel non stop with 6 kids. This is super inconvenient.
1) sitting at a stop. Engine running , SOC at 85% , ambient temp 101 degrees. In 15 min I’m at 0 SOC, no power in rear coach. No AC!!!
2) driving , same situation as listed above
3) shore power or external generator , no issues. No matter the temp.
4) I have spoken with 6 different tech support people at Thor. 1 at master Volt 1 at Reliable battery. Nobody has a clue what’s going on and they have been pretty honest. They don’t really know anything more about these systems than what I have read in the manual. 1 guy at Thor thought it might be the overloads for the alternator and battery swapped. But I can’t find those connectors as he described.
5)this just started today. BALMAR display , *no service available for this selected device*

Hey Maxwell1121
Did you custom the inside to fit 6 kids?

[Chance]

Originally Posted by Scubawise

I think our inverter paperwork shows if batteries detected at 10.9 or below shutdown inverter..

With lithium batteries, voltage should not get that low, particularly with engine running and with 280 Amp alternator. No freaking way this should ever happen unless something is not right (as in not wired correctly, broken, inoperable, or wrong equipment selected in the first place). That voltage is adjustable on many inverters, so shouldn’t trip under given conditions.

It is far more likely that when temperatures are extra hot, and the air conditioner needs more power, the current being supplied by only 2 lithium batteries exceed the BMS rating (temperature or current), and then trips.

I can’t say for sure, but if I was betting, that’s where I’d place my money; hence why I would look there first to confirm or exclude.


P.S. — All these kinds of issues are avoidable with proper design and build. In my opinion there is no excuse to get this stuff wrong.

[Travelin' Texans]

If you need both A/Cs running start the generator, that's what it's for!

[Chance]

Originally Posted by Scubawise

This could be it. When we wanted the inverter hooked to AC, OUR 30 year tech and his son an electrician said something like this would happen.

They suggested always rub the generator while driving for AC. IF no AC our inverter powers everything else

Your Vegas is almost certainly very different than the OP’s motorhome.

[Chance]

Originally Posted by Travelin' Texans

If you need both A/Cs running start the generator, that's what it's for!

I have assumed this unit does not have traditional Onan generator. Thor specs I could find below. Engine-driven alternator replaces Onan if I’m reading correctly.
.

[Bill Johnson]

Originally Posted by Travelin' Texans

If you need both A/Cs running start the generator, that's what it's for!

His generator is a battery bank, inverter and an alternator

[The Gritz Carlton]

Go purchase a rear hitch rack and a Champion 3400 generator (or similar) and plug coach into the 30A receptacle on the generator. It would be the same effect as being hooked up to shore power. The generator will run 3-4 hours on it's tank of gas. There's no way your existing alternator can replenish the batteries fast enough to run the A/C continuously.

[fourthgear]

I remember, I read someone had a charging issue with the House Batteries while driving & they found that the second alternator wasn't even connected , from the factory , the wire was ran , just not connected .

If the LI Batteries were at 100% when first starting the A/C unit , it should have had enough to run for an hour or two , before needing to charge the Battery (s) . I have the 400 AH LI & I can get at least 3-4 hours running the A/C ( to 20% ) before needing some method of charging , of course there is so much that can effect that figure , from RV to RV ,A/C BTU rating , no A/C can cool the outside , depends how well they are insulated .

[Bill Johnson]

Right, I looked up the amount of amps and it came out to 100 amps an hour but I figured 9 amps at 120 volts but it turns out it's 13 to 15 amps, it might be as high as 140 amps an hour plus the inverter loss

[Chance]

Originally Posted by The Gritz Carlton

Go purchase a rear hitch rack and a Champion 3400 generator (or similar) and plug coach into the 30A receptacle on the generator. It would be the same effect as being hooked up to shore power. The generator will run 3-4 hours on it's tank of gas. There's no way your existing alternator can replenish the batteries fast enough to run the A/C continuously.

Unless Thor is misrepresenting information, these types of motorhomes have a second stand-alone high-capacity alternator dedicated to house loads. If indeed it is a 280-Amp alternator (I accept OP’s word unless told otherwise) and the air conditioner is one of the common models Thor uses in vans (either 11,000 BTU/hr Power Saver or 13,500 BTU/hr Mach 10 pulling 10.3 Amps), the alternator shouldn’t even have to operate at 50% capacity to keep up.

The diagram below is probably for the higher-cost larger-battery electrical system that is optional, but should highlight the basic architecture for the most part.


P.S. — The days of 15~20 Amp (115 Volt) air conditioners for vans is hopefully well behind us. New goal should be improving on present 10-Amp units.
.