Chins BMS possibly the issue?

[ds0078]

I posted an issue with my four 200ah Chins batteries where when I place a heavy load like a microwave that my battery bank is shutting off. I received some great responses and made some adjustments to my wiring in hopes of resolving the issue. After making my modification I am still having the same problem. I am attaching a diagram of my build for anyone to look over and critique my wiring or any other possible issues, or do I have it correct?

My next question is does anyone know how many cells are in the case? If I have a BMS issue, I was thinking about cutting my batteries open and separating them from their cases and removing the Chins BMS and using an overkill BMS. Would this be an issue?

My installation area in my boat is pretty well protected in the living room. However space is an issue. I am thinking that I can get all the battery packs aligned better by removing them from the case and using a better BMS may solve my load issue. I know that returning them is the proper option, however I already have my boat in an off grid configuration and would have to rewire everything to run off generator power again while waiting on new batteries to arrive. This is my reasoning for not sending them back regardless of warranty (if I can keep from it).

I am attaching a couple of images taken PRIOR to rewiring to show my space limitations. So before ripping me a new one, remember the actual images of the batteries were before correcting wire lengths and positive and negative leads

I understand 12v but LifePo4 is a new learning curve. Thanks to Mr. Prowse and the people on this Forum I am learning.

Thank you all for your input and knowledge
D

 

[John Frum]

Is that a 4000 watt low frequency inverter running off a 12 volt bank?

4000 ac watts / .85 conversion factor / 12 volts low cutoff = 392.156862745 service amps.
392.156862745 service amps / .8 fuse headroom = 490.196078431 fault amps.
That is a metric frick ton of current.
The main circuit should be 2x 2/0 awg each with its own 300 amp fuse.
What wiring guage are you running?

Also the breaker looks cheap and nasty.
Also assuming that wire is 0 awg its oversized for the wire and way undersized for the current.

 

[ds0078]

Is that a 4000 watt low frequency inverter running off a 12 volt bank?

4000 ac watts / .85 conversion factor / 12 volts low cutoff = 392.156862745 service amps.
392.156862745 service amps / .8 fuse headroom = 490.196078431 fault amps.
That is a metric frick ton of current.
The main circuit should be 2x 2/0 awg each with its own 300 amp fuse.
What wiring guage are you running?

Also the breaker looks cheap and nasty.
Also assuming that wire is 0 awg its oversized for the wire and way undersized for the current.

Original post https://diysolarforum.com/threads/2500-watt-lifepo4-rated-output.31943/

Inverter is 4000 watt pure sign wave.
Wire size is zero, however I do not have enough items on my boat to pull the amount of current that I could possibly pull. Well I guess if I turned everything on at once like my microwave, refrigerator and water heater I could get close.

The battery bank is shutting off at about 2100 watts and or 100 amps. No breakers or fuses blown. The batteries simply shut down for about 5 to 10 seconds before they turn back on. My inverter has a passthrough mode, so when I want to run the microwave I am having to turn on my generator just to run the microwave for 5 minutes.

I purchased the 4000 watt inverter because in one of Wills videos he said buy the biggest you could afford, so I did LOL.... Even though I will never use 4000 watts, I would like to be able to easily pull 3000 if I had to.

The best option is to probably just fire up the generator and run through the passthrough mode, but I would like to know the system is performing as it should and not be required to fire up the generator. I would like the option.

I am not happy with the breaker. I have already had to replace one. So that is on the todo list.

 

[John Frum]

Wire size is zero, however I do not have enough items on my boat to pull the amount of current that I could possibly pull.

zero = 0 = 1/0 awg which is good for ~230 service amps.
Should run your microwave.

Well I guess if I turned everything on at once like my microwave, refrigerator and water heater I could get close.

Do you have a wife or children?
I design systems for the least tech savvy person in the loop.

The battery bank is shutting off at about 2100 watts and or 100 amps.

100 amps * 12 volts low cutoff = 1200 dc watts.
Our numbers are not in accordance.

No breakers or fuses blown.

Please replace that cheap and scary breaker with a quality fuse.
What size are the battery studs?

The batteries simply shut down for about 5 to 10 seconds before they turn back on.

Sounds very much like a BMS disconnect.
Possible reasons are over-current and under-voltage.
Since 4 of those batteries in parallel are capable of 400 amps aggregate I suspect under-voltage.
High resistance plus high current causes voltage drop along the circuit.
I suspect bad joinery, and sub par components.
My prime suspect is that breaker.
Are the cables pure copper or are they copper clad aluminum?
Check for hot spots at the joints and voltage drop along the path under heavy load.

I purchased the 4000 watt inverter because in one of Wills videos he said buy the biggest you could afford, so I did LOL.... Even though I will never use 4000 watts, I would like to be able to easily pull 3000 if I had to.

The idle draw on that beast is likely very high.

The best option is to probably just fire up the generator and run through the passthrough mode, but I would like to know the system is performing as it should and not be required to fire up the generator. I would like the option.

I am not happy with the breaker. I have already had to replace one. So that is on the todo list.

Quality thermal breakers in that form factor only go up to 250 amps.
The most trusted ones only go to 200.
Personally I draw the line at 150amps.
Please replace with a proper fuse.
If your studs are 3/8ths inch I suggest this.

Eaton's Bussmann Series CFBAR1-M8XSP Mounting Bar | Waytek Wire

Eaton's Bussmann Series CFBAR1-M8XSP (CBBF-MBC) MRBF Mounting Bars with M8 stud and 3/8" mounting hole work with CBBF Series Fuses and available at Waytek.

www.waytekwire.com

Eaton's Bussmann Series MRBF-250 Marine Rated Battery Fuse | Waytek

Eaton's Bussmann Series MRBF-250 Marine Rated Battery Fuse, rated at 250A for 58VDC systems with bolt-down design are available at Waytek today.

www.waytekwire.com

If not I suggest this

TFB2-250, 250A Class T Fuse Kit | DonRowe.com

The TFB2-250 offers 250 amps of over-current protection and provides safe operation of your inverter.

www.donrowe.com

 

[HOU_Castle]

Another suggestion is to test your battery BMS individually to answer your original question.

 

[ds0078]

Another suggestion is to test your battery BMS individually to answer your original question.

That I can do. I will have to do a little disassembly, but doable. Thank you!

 

[ds0078]

zero = 0 = 1/0 awg which is good for ~230 service amps.
Should run your microwave.


Do you have a wife or children?
I design systems for the least tech savvy person in the loop.

100 amps * 12 volts low cutoff = 1200 dc watts.
Our numbers are not in accordance.

Please replace that cheap and scary breaker with a quality fuse.
What size are the battery studs?

Sounds very much like a BMS disconnect.
Possible reasons are over-current and under-voltage.
Since 4 of those batteries in parallel are capable of 400 amps aggregate I suspect under-voltage.
High resistance plus high current causes voltage drop along the circuit.
I suspect bad joinery, and sub par components.
My prime suspect is that breaker.
Are the cables pure copper or are they copper clad aluminum?
Check for hot spots at the joints and voltage drop along the path under heavy load.

The idle draw on that beast is likely very high.

Quality thermal breakers in that form factor only go up to 250 amps.
The most trusted ones only go to 200.
Personally I draw the line at 150amps.
Please replace with a proper fuse.
If your studs are 3/8ths inch I suggest this.

Eaton's Bussmann Series CFBAR1-M8XSP Mounting Bar | Waytek Wire

Eaton's Bussmann Series CFBAR1-M8XSP (CBBF-MBC) MRBF Mounting Bars with M8 stud and 3/8" mounting hole work with CBBF Series Fuses and available at Waytek.

www.waytekwire.com

Eaton's Bussmann Series MRBF-250 Marine Rated Battery Fuse | Waytek

Eaton's Bussmann Series MRBF-250 Marine Rated Battery Fuse, rated at 250A for 58VDC systems with bolt-down design are available at Waytek today.

www.waytekwire.com

If not I suggest this

TFB2-250, 250A Class T Fuse Kit | DonRowe.com

The TFB2-250 offers 250 amps of over-current protection and provides safe operation of your inverter.

www.donrowe.com

No wife or children onboard.

Wire is marine grade tinned copper.

I realize you are only as strong as your weakest link. So the proper high performance fuse will be implemented.

In my drawing I have 40 inch cable connections from batteries 2 and 3 and my positive and negative leads from 1 and 4 to my inverter are similar in length. Do you see a real issue with the batteries 2 and 3 cables being longer actually causing a problem? I know it isnt optimal, but without cutting into my boat it was my only option. That is why I have considered removing the packs from their cases and using a high quality BMS hoping I could fit all the packs in the cabinet without any major boat structure modifications and have them all a little closer together.

I read a post on here of the Chins 200ah batteries and their BMS just not living up to expectations. Will had given them a decent review on the 100ah so I decided on the Chins. Not that he is to blame or anything for my bad decisions, but for the price (you get what you pay for) I thought I was making a better decision.

If removing the cells from the case is a bad idea, my next option is to order cells from aliexpress when I get to my long term port.

I will get a proper fuse on order today. Thank you for all of the suggestions.

Your detailed responses and links are very appreciated!

 

[Cajunwolf]

I'm keeping my eye on this thread because I'm buying 3 Chins 12V 200AH batteries for my RV.

 

[John Frum]

Do you see a real issue with the batteries 2 and 3 cables being longer actually causing a problem?

I don't think it is significant.
This reference will tell you everything you need to know about wiring a battery bank.

Wiring Unlimited

Wiring Unlimited is a great resource that covers many many common topics and questions relevant to DIYers. It is a free E-book from Victron Written by Margreet Leeftink. Check it out! Download

diysolarforum.com

 

[ds0078]

I don't think it is significant.
This reference will tell you everything you need to know about wiring a battery bank.

Wiring Unlimited

Wiring Unlimited is a great resource that covers many many common topics and questions relevant to DIYers. It is a free E-book from Victron Written by Margreet Leeftink. Check it out! Download

diysolarforum.com

Thank you. New quality fuse ordered. I will have it installed before the end of the week.

 

[ds0078]

I'm keeping my eye on this thread because I'm buying 3 Chins 12V 200AH batteries for my RV.

Might want to read this persons post as well on the Chins. I know amazon has a lot of happy reviews.... but.

CHINS 200Ah LiFePO4 battery test/review

I ordered two CHINS 200Ah LiFePO4 batteries through Amazon, and they arrived today. I did the unpacking, took some pictures and will post my testing and review progress over the coming days. The batteries are warming up to room temperature today. Once they warm up, I will start. The unpacking...

diysolarforum.com

 

[Cajunwolf]

Might want to read this persons post as well on the Chins. I know amazon has a lot of happy reviews.... but.

CHINS 200Ah LiFePO4 battery test/review

I ordered two CHINS 200Ah LiFePO4 batteries through Amazon, and they arrived today. I did the unpacking, took some pictures and will post my testing and review progress over the coming days. The batteries are warming up to room temperature today. Once they warm up, I will start. The unpacking...

diysolarforum.com

Yeah, I read that one and many more on different sights. Overall, Chins ranks about 75% approval, with most people satisfied and or happy with their batteries, which is pretty good considering. Heck, I know folks who b*tch about Battleborn, LoL. I guess at this time, I'm up against the wall and need to buy batteries now before the prices start skyrocketing next year, and they will. I'm not a rich man and trying to get as much bang or amperage as possible for the limited bucks I have. I looked into building my own, but for the price I'm being offered these three batteries, I couldn't come close. Heck, if I have BMS issues, it's worth knocking the tops off and swapping it out for the capacity. I'll be putting all three in parallel to power my small class C RV. I Haven't bought them yet, so I'm following your thread to see how your issue works out. Thanks for the feedback.

 

[ed6269]

I ran into the same problem with my 12 volt system, it would almost start a sump pump in my house with used lead acid batteries so I thought I would upgrade to some Lion energy safari LiFePo4 and when I tried to start the sump pump it did nothing, not even close to starting.
The reason the lead acid batteries worked better is because there's no BMS , my Lion energy batteries come with a 150 amp BMS ,when using a 12 volt system with a 150 amp BMS 150x12 or 13 volts you can only run 1950 watts before the BMS says enough.
Your Chins batteries (though great Batteries) only have a 100 amp BMS which with a 12 volt system I believe is only good for a 1300 watt draw before the BMS says enough. If you want to draw 4000 watts with a BMS battery you will have to go to a 24 volt or 48 volt inverter.
I don't know for sure what I saying is true or not but when I went 24 volts with a 3000 watt inverter the pump started no problem.

 

[Atomic Ed]

I have the chins 24v 200ah battery and it has a 200a bms in it but my inverter is less than 3kw, I believe what ed6269 said is your likely issue and moving to 24v would be a better approach for your inverter. My understanding is anything beyond 2kw at 12v is not good because of the high amps and necessary large wiring.

Does your invertrr support 24v input as well?

 

[ericfx1984]

So if you look at my existing system.. I had a very similar problem, while I was using lead acid batteries, and a 3000 watt victron inverter, there were some similarities, for starters I was using the Chinese 300 amp breaker, I was also using 1/0 gauge wiring

In my case it went something like this if I tried to run things like the microwave or a tea kettle the breaker would trip

And I thought to myself even though I know the wiring is undersized the previous owner has been using it for a long time, it shouldn't be a problem.. on top of that I'm not hitting that many amps of draw so it really shouldn't matter

But the voltage sag on high loads was pretty evident

I started doing some math and realized that the breaker was popping somewhere between 80 amps and 150 amps

Which of course meant that either a this breaker was way out of spec to begin with OR be this breaker had been damaged by being popped over and over likely due to the huge voltage sag on the inverter side



The interesting thing to note is that the voltage sag read at the inverter was usually significantly less than the voltage sag read directly on the battery Bank

When I pulled the breaker I found melted plastic behind it

Anyway I replaced the breaker with the exact same thing... And while I was no longer popping it ran extremely hot..m all the wire terminal connectors where extremely hot as well

At this point I knew what was happening...

These were thermal breakers and one of the problems with thermal breakers is the intentionally create a current choke point designed to heat up a piece of spring steel... The spring steel heats up, The temper changes, a disconnect takes place the problem is is their intentionally making the connection worse in order to affect this temperature change

To make matters even worse the lugs really aren't appropriately sized for moving 300 amps or in your case 400 amps

So I figured it was time to do this right I pulled the breaker from service and doubled up on the 1/0 gauge wire, keep in mind 21/0 gauge lines is the equivalent of a 4/0 gauge line as they have the same cross section

So I ran 2, 1/0 gauge wires to the inverter negative and then on the positive side each one of them had a 200 amp ANL fuse

Now I can effectively hit the battery with 400 amps and since I already knew that I could operate on 200 amps even if one line went down there was enough there to operate best part is the ANL fuse has a significantly wider connection point than any breaker I've ever seen and they're cheaper and way more reliable

Needless to say I haven't had any issues... I have even ran the A/C for a small period of time

 

[740GLE]

Cheap breakers = = headaches

 

[ericfx1984]

Cheap breakers = = headaches

And sometimes fires

 

[meetyg]

Just a thought: Did you fully charge all 4 batteries beforehand?
If each battery has a different SOC, maybe one of them will reach lower voltage and then the others take all the load, and therefore shutoff.

Kinda like top-balancing battery cells, each pack should be at the same SOC of the others. The thing is that with Lifepo4 you can't rely on voltage to get the SOC.
I would fully charge each battery separately (maybe using shore power) and then put them back in parallel.

 

[DJSmiley]

Agree with the breaker

Bypass that one for testing purposes. I still don't get why people would install those automatic breakers.

Just use a fuse. A breaker is fine for a house switchboard, where you will occassionally overload/trip a breaker and want a fast way to reset.

In battery setups, it would only trip if there is something really wrong, and in those cases I don't mind changing a fuse manually.

Yes, you can easily disconnect the inverter for maintenance... but let's be honest... How many times do you need to do that? Just unscrew a lug and make sure to isolate it properly if you need to do maintenance, but that shouldn't be done frequently anyway.

I *could* add connectors to all wires on my car's engine and removable hoses with fast disconnects.. Makes it a lot easier if I have to swap the engine... But that doesn't make sense... can cause issues and unlike refilling the fuel tank... im not going to do that every week

 

[John Frum]

In battery setups, it would only trip if there is something really wrong, and in those cases I don't mind changing a fuse manually.

If I ever had a 100 plus amp over-current protection device trip/blow I would make sure the issue was addressed before I put the system back in service.
If it were a breaker I would shop for a new one as the one that tripped on fault current would very likely be pitted.
Its my understanding that once they are pitted the chances of them welding shut go up significantly.