Rv upgrade 280 lipo4 battery HELP needed

AlmostfreeSolar

New Member
Joined
May 20, 2021
Messages
3
Please help

I have recently put 2 12volt 280ah 4x3.2 in my coach

Each battery has a Daly 150a Bms

Here's my issue
When my furnace kicks in my led lights go dim if I turn off the 15 watt led light the furnace powers up.

I have 4 batteries in parallel with 150a daly bms

Then 4 batteries in parallel
With a second 150a daly bms
Then I run both batteries 12 volts in series to my coach

I am consistently showing 13.08v or higher and it's all backed by 1000 watts of solar with 2 victron energy 50a controllers

Please help I'm ready to go back to my problem free led acid
I had 0 issues before this upgrade except for the maintenance of led acid
 

AlmostfreeSolar

New Member
Joined
May 20, 2021
Messages
3
Also I use to be able to jump my chassis batteries with a flick of a boost switch now it does nothing. I read these batteries are only for storage not cranking amps
 

2BZ2Ranch

New Member
Joined
Dec 13, 2019
Messages
19
Location
Flagstaff, AZ, U.S.A.
Please help

I have recently put 2 12volt 280ah 4x3.2 in my coach
You built your own 12V batteries, 4 280A cells in series with a 150A Daly BMS - correct? And you made two of these.
Each battery has a Daly 150a Bms
(
Here's my issue
When my furnace kicks in my led lights go dim if I turn off the 15 watt led light the furnace powers up.
What kind of furnace does your coach have?
I have 4 batteries in parallel with 150a daly bms
I assume you mean series.
Then 4 batteries in parallel (do you mean series?)
With a second 150a daly bms
Then I run both batteries 12 volts in series (do you mean parallel) to my coach (Two 12V batteries in series would yield 24V.)
Something doesn’t seem right with your explanation.
I am consistently showing 13.08v or higher and it's all backed by 1000 watts of solar with 2 victron energy 50a controllers
This almost sounds like you’re possibly seeing PV voltage.
Please help I'm ready to go back to my problem free led acid
I had 0 issues before this upgrade except for the maintenance of led acid
If you built your LFP batteries correctly and wired them into your coach in the same manner as your LA batteries,,, then why wouldn’t they work? I suspect there is a “build” or “wiring” problem. Twelve volt batteries are twelve volt batteries.
Can you post a picture or two of your batteries and wiring?

I’ve been RVing for decades and have never heard of a problem like you describe unless something got messed up.
 

jvbutter01

Solar Enthusiast
Joined
Aug 20, 2020
Messages
201
You built your own 12V batteries, 4 280A cells in series with a 150A Daly BMS - correct? And you made two of these.

What kind of furnace does your coach have?

I assume you mean series.

Something doesn’t seem right with your explanation.

This almost sounds like you’re possibly seeing PV voltage.

If you built your LFP batteries correctly and wired them into your coach in the same manner as your LA batteries,,, then why wouldn’t they work? I suspect there is a “build” or “wiring” problem. Twelve volt batteries are twelve volt batteries.
Can you post a picture or two of your batteries and wiring?

I’ve been RVing for decades and have never heard of a problem like you describe unless something got messed up.
I think your not quite understanding him... 4 cell 12 batter would only be a series setup. Not parallel. Parallel would be only 3.2v at (4x280ah)
if he put 4 12v batteries in series that would make it 48v right? Not many RV's run on48v. he said parallel so the amperage increments, not the voltage.
 

2BZ2Ranch

New Member
Joined
Dec 13, 2019
Messages
19
Location
Flagstaff, AZ, U.S.A.
@jvbutter01,
I am very familiar with RVs and very familiar with solar/lithium upgrades to RVs. I do know of some custom coaches that have 24V systems but none at 48V (although some custom yachts DO have 48V systems). @AlmostfreeSolar still isn’t fully or accurately describing his design. He is asking for help and I am attempting to do so.

He says “I have recently put 2 12volt 280ah 4x3.2 in my coach” I read that as two (2) twelve volt (12V) batteries, built 4s using 3.2V cells. His following description though is confusing.

AlmostfreeSolar said:
I have 4 batteries in parallel with 150a daly bms
I assume you mean series.

Here, he says what he says- 4 batteries in parallel. Do you read that differently? I read 1,120 amps @ 3.2V. We can assume he misspoke and meant four 3.2V 280Ah cells in series but I would like to clarify that.

“ AlmostfreeSolar said:
Then 4 batteries in parallel (do you mean series?) {He did say parallel}
With a second 150a daly bms {I read this the same as above but for this second battery}
Then I run both batteries 12 volts in series (do you mean parallel) to my coach (Two 12V batteries in series would yield 24V.) {This is my conclusion to his description}
@jvbutter01, do you read this differently than I? I read that as his second, 1,120AH, 3.2V batteries are connected in series to yield a 6.4V, 1,120AH battery.

Please do not misunderstand me. I most definitely recognize that many members on this forum do not have English as their primary language. I am not making any assumptions otherwise. I am trying to understand what @AlmostfreeSolar is describing so to better understand his problem and try to help him.

RV furnaces typically pull between 11 to 15 amps DC. His furnace and chassis battery “boost“ switch worked before the LFP upgrade. Something is wrong with his system.
If @AlmostfreeSolar built his battery correctly and installed them in reverse order the way his LA came out,,,, there should not be any problems. But he does have a problem. I’m just trying to help.

Best regards,
Dave
 
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