Lithium BMS Question

[TacomaJoe]

Okay, time for what I hope is the wrap up report.

I installed a LiTime 140 ah, 150 amp BMS, Bluetooth battery this morning after fully charging it overnight. It came with a 52% state of charge, and didn't require any particular procedure to start topping it off. The LiTime Bluetooth app immediately started giving data, as it sat there charging. After I got the battery in, I installed a Progressive Dynamics lithium compatible converter, and reprogrammed my solar controller for lithium.

The original question was whether the jacks would work, and they do.

All of the other systems seem to work fine, with one odd exception. The LED lights in the trailer flicker when on battery alone. I went out and retightened all of the connections, and we'll just wait to see what happens on that.

Thanks to everyone who contributed to this discussion and to helping me work through this.

You might try to add a little more load while the lights are flickering. Maybe turn on a fan or something. I'm wondering if the BMS has a low current issue.

 

[richp-FRF]

Well the app shows that the BMS is still balancing, so that might be part of it. I'm going to wait until that is no longer going on before I try what Aussieguy suggested.

 

[TacomaJoe]

I wouldn't think BMS balancing would affect output current. In my trailer the LED above the dinette table would flicker when I used the USB charging port near it. I can't explain how they interacted but it was repeatable.

 

[richp-FRF]

Well the balancing is over, and I have been running on only 12 volts for about 3 hours now with no flickering LED lights and fantastic fans providing the most notable loads. Whatever it was seems to have healed itself.

 

[TitanMike]

How cold is it inside the trailer.

I find one LED light in my bathroom, coldest part of my trailer, will flicker slightly until the bathroom reaches mid-upper 60's.

Lately it's ben going down as low as upper 40's at night. No heat vent in bathroom and sometimes forget the ceiling vent is open.

Rest of the time no flickering.

That said, sometimes LED lights will flicker for no apparent reason.

 

[richp-FRF]

I'm on the Gulf Coast of Alabama, and the temperature was pushing 80 today. I don't think that was the problem.

But as I said in an earlier post,it's been running on just pure battery for over 3 hours now without any flickering. So hopefully I was just in some kind of transitional phase with the battery when I first saw the flickering, and now it's past. Emphasis on hopefully.

 

[richp-FRF]

As a test, I shut off the converter last night after dinner, and ran on just the battery all night.

Between dinner and bedtime, the SOC dropped to 88%, because I was running lots of lights and two fantastic fans. In addition to some small parasitic loads, the only real draw overnight was a fantastic fan running at medium speed, and it was at 83% SOC when I got up. And no flickering at any time during the evening or early this morning...

I'm going to leave the converter off today and see how much my solar system brings it back up under the cloudy conditions we are predicted to have down here on the Gulf Coast.

 

[richp-FRF]

Well the new lithium battery is working well in conjunction with my solar panels and charger. But a small mystery has emerged.

By itself, my solar system brought it back up to 100% in about 6 hours today, under cloudy conditions. So far so good.

But I happened to be watching the app as the SOC approached 100. Lo and behold, at 99%, almost all the LED lights started flickering again. And they continue to flicker at 100% right now. Interestingly, several lights of a different type that I have replaced over the years do not flicker like the original ones.

So the battery replacement project went well, but it appears that some of my LEDs don't like the full load of juice that my solar charger and converter put into the battery. At least that's my current theory...

 

[TitanMike]

Well the new lithium battery is working well in conjunction with my solar panels and charger. But a small mystery has emerged.

By itself, my solar system brought it back up to 100% in about 6 hours today, under cloudy conditions. So far so good.

But I happened to be watching the app as the SOC approached 100. Lo and behold, at 99%, almost all the LED lights started flickering again. And they continue to flicker at 100% right now. Interestingly, several lights of a different type that I have replaced over the years do not flicker like the original ones.

So the battery replacement project went well, but it appears that some of my LEDs don't like the full load of juice that my solar charger and converter put into the battery. At least that's my current theory.

If this is a big issue you can install a 12v "voltage stabilizer" in the circuit that supplies your lights. Amazon sells them and range from ~$16 and up depending on current rating. Find fuse that controls lights and install a "stabilizer" rated at least as high as fuse size. Could well be cheaper than replacing lights that are,or will soon be, flickering.

Other devices like water pump, fans, slides, power awnings, and tongue jacks won't be affected by the higher voltage as they generally draw down their operating voltage when in use due to higher current and line loss.

 

[Aussieguy]

If this is a big issue you can install a 12v "voltage stabilizer" in the circuit that supplies your lights. Amazon sells them and range from ~$16 and up depending on current rating. Find fuse that controls lights and install a "stabilizer" rated at least as high as fuse size. Could well be cheaper than replacing lights that are,or will soon be, flickering.

This ^^^^^

I call the line stabilizers.... little round magnets
5 seconds to install , just wrap the power wire for the lights through the magnet a couple of times

IF .........the flickering don't stop... put the magnet close/at the first LED in the circuit unscrew LED from ceiling/wall to find the wire

closer you put them to the appliuance end is usually better
last time I said they was magnets got chewed out
but they look like ones and are sightly magnetic

 

[TitanMike]

This ^^^^^

I call the line stabilizers.... little round magnets
5 seconds to install , just wrap the power wire for the lights through the magnet a couple of times

IF .........the flickering don't stop... put the magnet close/at the first LED in the circuit unscrew LED from ceiling/wall to find the wire

closer you put them to the appliuance end is usually better
last time I said they was magnets got chewed out
but they look like ones and are sightly magnetic

Those do nothing to stabilize line voltage and aren't magnets. They're "Ferrite Chokes" and used to prevent stray RF from entering a device on power cords.

A voltage stabilizer is a device that regulates the voltage from an unstable or higher than desired at any given time to a steady voltage within the desired range.

Ferries Chokes won't solve the OP's issue unless it's caused by an RF source like a nearby radio transmitter or "noisy" electronic device.

 

[richp-FRF]

Aussieguy, thanks.

I have 23 separate puck lights, all but two of which flicker. If there's a solution that doesn't involve teetering on a ladder while I replace each individual light, I would prefer exploring that option. Ideally, that would involve placing some kind of a regulating device on the 12 volt line coming into my fuse panel.

Living with it a little longer today, once the voltage drops somewhere below 14.0, the lights no longer flicker. The pattern seems to be that while the solar panels get the lithium battery near 14.4 volts, the lights don't like it. Once the controller cuts the panels out and the voltage drops, the lights are stable.

 

[alcouch33]

Is anyone with a 100 AH lithium battery setup and a 100 amp BMS experiencing difficulties operating their landing gear motor because of the higher startup current load?

I have a Class C with 2 110 amp Battle Born Lithium and i have to use the chassis battery switch along with them to start generator or it shuts down the 12v system

 

[reidfo]

Aussieguy, thanks.

I have 23 separate puck lights, all but two of which flicker. If there's a solution that doesn't involve teetering on a ladder while I replace each individual light, I would prefer exploring that option. Ideally, that would involve placing some kind of a regulating device on the 12 volt line coming into my fuse panel.

Living with it a little longer today, once the voltage drops somewhere below 14.0, the lights no longer flicker. The pattern seems to be that while the solar panels get the lithium battery near 14.4 volts, the lights don't like it. Once the controller cuts the panels out and the voltage drops, the lights are stable.

Just a guess, but have you checked your 12V connections to make sure they're sound? Lugs tight, no corrosion, negative connections to frame making solid connection, no paint in the way?

 

[richp-FRF]

I go through everything that I can get my hands on once a year, to be sure that it's tight and clean.

I think I'm beginning to see the pattern pretty clearly. When the solar system takes the lithium batteries above 14 volts, the older puck lights start to flicker. The newer, replacement lights do not flicker. When solar charging stops, and the voltage as shown on the app drops to somewhere in the operating range of 13.8 and below, the flickering stops on the old lights. And this happens to the older lights on all of the various circuits throughout the trailer -- living room, bathroom, bedroom.

Because I'm still giving the batteries and solar panels a bit of an initial test/workout, I haven't seen what happens when I am running with the converter turned on. After one more day of seeing how long it takes the panels to reach 100% SOC, I'm going to try that.

Depending on the outcome there, I suppose I can either learn to adapt to this, or (ideally) find a relatively straightforward filter that I can install on the 12 volt line coming into my fuse panel.

 

[JLeising]

A silicon diode in the line supplying the lights will drop the voltage about 0.6 volts.
A different thought - the battery control circuit on your LiFePO4 batteries should be entering cell balancing mode at about the voltage where you are seeing the issue. Possibly small changes in the batteries during cell balancing are sufficient to impact your lights. I suspect a large capacitor between the line feeding the lights and ground might solve or reduce such an effect.
FYI, Jim

 

[XSquid]

Not sure if you have bought the battery yet, but I have 2 LITIME 100 AH BT batteries and usually only connect one to the trailer, maintaining the other as a spare. I have a 2024 Minilite 2502 with the Lippert stabilizers and have never had a problem with the BMS tripping. If you want a picture of my batteries to ensure they are the same that you are looking at I would be happy to provide.

 

[richp-FRF]

Thanks for the offer Xsquid. I already have purchased and installed a Litime 140 ah battery with a 150 amp BMS and Bluetooth. I still have a few things to sort out with my solar system, but so far, so good.

 

[Aussieguy]

I have 23 separate puck lights, all but two of which flicker.

ferrite chokes only needed at the beginning of the light circuit
if the 2 lights are on the same circuit ONE choke is all that is needed

Interference can be caused by two power lines running together in a bundle of wires
example.... wire for the lights sits next to the main solar cable... The charging cable has higher current and produces a magnetic field that effects the little wire... can cause annoying blink

I doubt it is voltage related.... because it would affect more lights and other appliances.
if only 2 lights flicker ... start at the one closest to the lightsitch

 

[Aussieguy]

Not sure if you have bought the battery yet, but I have 2 LITIME 100 AH BT batteries and usually only connect one to the trailer, maintaining the other as a spare.

join them together and make a 200ah battery
less work and they are designed for this type of thing.

add a couple of solar panels and go have fun , especially since you in southern California
you won't be playing with battery all the time


PS they will die of old age ... before you can wear them out from usage!
unless you add a inverter and stress them to death.