Renogy 200ah BT new battery won't charge! BMS fault? or Part missing?

[obd.tech]

This battery is either in shelf mode & won't accept a charge, or maybe there is a switch or temperature sensor missing ..... So the BMS says "NO!"

I can't get the DC home app to work (separate issue & thread started!)

I removed the false top cover lid from this battery case to reveal 6 small access holes & was able to check the cell pack (4p4s) voltages, all 3.29v.
The battery terminal voltage is 12.28v. the cell pack internal voltage controlled by the BMS is 13.2v.
Under this lid, on 1 side is the Bluetooth device, on the other side is a twin wire/connector socket with nothing connected!????

I believe the early Renogy LFP batteries had an 'On' switch .... Is this my problem?
I think it's more likely to be a temperature sensor socket & it's missing? ....
I got brave an decided to see what happens if I trigger this 2 wire circuit?

When linked to a power supply (13.8v 5A), the battery will switch on for 3 seconds every minute or so and take about 50w.
If I link a 5w 12v auto bulb (resistance) across these 2 pins, the charge cycles at about a 50% PWM duty cycle every 3 seconds.

My questions are....
1, can someone whip the lid off their battery to see what's missing? (Easy! Takes seconds, a little glue lightly holds it down & super easy to redo)

2, what BMS is fitted to these?

3, who actually makes this battery? I know the case is the same as chins etc etc

4, if this battery is missing the temperature sensor & I have to trick the BMS, what resistance value can I place across the terminals for it to be happy?

Photos of my battery below. Thanks for all that help me fix this !!!!!

p.s. I found a similar 'issue'? in this post on the group:-

Overkill / Jiabaida / JBD BMS faulty high temp cut off behavior

Hello, Following the build of a 4S 160Ah battery with a JBD 200A BMS, I wanted to perform some tests on the safety triggers. It seems to me that these BMS are reputed to be rather reliable and well designed but I noticed a strange behavior of the BMS for everything that is triggering the...

diysolarforum.com

 

[obd.tech]

I got the DC Home app working and the BT communicates but only if I bridge the mystery connector with a SCC temperature NTC sensor across it (about 11k ohm).
The BMS is falsely reporting 2 cell voltages way off from my measured readings. 0.1v -4.9v randomly jumping about!

What BMS brand do Renogy use?

Could this be a connection issue or is the BMS toasted?

Time to open the case! Any tips?

 

[obd.tech]

Fault fixed!
Turned out to be a broken balance lead connection, BMS wasn't happy, so did it's job & refused to work! All as designed.

The internals of this battery are pretty impressive! All nicely laid out. Large welded Ali busbars across each 4 x50ah cell pack (16cells).
Looks like 2 main positive cables of about 25 or 35mm? silicone each, & the same gauge for the negative on the cell pack.
Nylon spacers between cell groups, temperature sensor on the top of the middle cells (& in BMS I believe).
BMS is placed on the side of the cell pack & looks a decent size, this has a max of 200A output!
Anyone wondering to buy 1 of these then I would say the internal build quality looks really good

The mystery 2wire socket must be some factory activation port, as the battery failed to activate until this circuit was triggered (like the early Renogy 100ah batteries, I think I saw once?)

A couple of photo's from my key hole surgery session.

 

[gmakhs]

Do you have any more pics of the surgery ???
How easy was to open the box ?

 

[obd.tech]

Steel ruler and Stanley knife repetition until it finally worked through about 2.5/3mm? Lid & the support 10mm braces.
It was pretty tough going, but enabled me to find & rectify the fault.
I was also able to manually probe into the cell packs and manually top balance them (over 250mv DV from factory!)
Bit difficult to take photos through the limited access opening I made, what else did you want to view?

 

[gmakhs]

I was hoping to see what BMS they use and what cell but if I understand correctly you opened only the small top cap not the whole box right ?

 

[obd.tech]

Correct, I didn't open the lid further as I found the issue.
Unable to see the cell terminals that can identify the brand, as the busbars are welded over them.
The BMS looks a decent size & is red like in the advert pictures (tho on the opposite side in reality)

 

[Danpro]

we have the same problem, with my brend new Renogy battery ! But i don't want to break the case now

 

[Danpro]

I got the DC Home app working and the BT communicates but only if I bridge the mystery connector with a SCC temperature NTC sensor across it (about 11k ohm).

do you stay with this setup ?

 

[obd.tech]

Yes the DC home works ok (my android version was the issue?)
What info on your faulty battery does the app show?
What have Renogy said to you about warranty?
(My battery was purchased as faulty, buyer was refunded for the faulty purchase, I like to fix things )

To activate a battery in sleep/shelf mode, a charge needs applying to it for a few seconds!!

 

[Danpro]

No my DC home app don't communicates with the battery.
It's your DC Home app communicates with the battery before you put your NTC sensor ?
It very difficult to have a good answer from Renogy
I made 4 videos but I don't know if anyone really understands how their battery works
I'm waiting for their decision, but I haven't received anything official yet.

Did you buy this faulty battery from Renogy and how much you paid for it ?

 

[Danpro]

After 10 days, 8 emails, 4 videos, about 10 hours lost....and it all starts again

News from Renogy

Thank you for providing the requested information.

What we're going to do is, we're going to raise this to our designated team in order to review the issue. What we can suggest for now is to stay tune for updates and rest assured that we'll be providing an option for this battery issue.

 

[Danpro]

And now I must paid shipping for return this faulty battery, more than $100.00 box.... very poor company and maybe we have a refund, not sure.... I never bought again at RENOGY....

 

[chriscappuccio]

i buy renogy products on walmart.com (usually cheapest) or amazon (cheaper than renogy's site)...Both have return policies that would allow me to return a fully faulty item without paying for shipping. how did you buy it?

 

[Danpro]

Directly from the Renogy site, also I opened a dispute with the help of PayPal, because Renogy only stretches the time. every day it is a new department that must send me a return label, but I still have nothing ... I am now at 18 emails to send... it's really a joke

 

[zorrobyte]

Directly from the Renogy site, also I opened a dispute with the help of PayPal, because Renogy only stretches the time. every day it is a new department that must send me a return label, but I still have nothing ... I am now at 18 emails to send... it's really a joke

After having issues with Renogy myself over the years, there's no way I'd buy their stuff and expect support. Their DC-DC MPPT controller also likes to snap bolts on terminals due to poor materials.

 

[chriscappuccio]

Just send them an email to their financial department saying that you haven't received a promised RMA return and you keep getting shuffled around. Tell them that you have been unable to resolve the dispute and you are going to charge back with your credit card provider. Easy Peasy.

 

[Substrate]

Also note that sometimes when a company gets large, they provide a larger target to battery scammers - which unfortunately affects the rest of us normal consumers who have real issues.

Like providing tech-support for non original-owners. Ie, used batteries found at a swap meet, and second owner demanding tech-support for unknown issues due to previous owners.

Or, they may be willing to look at a second-hand battery, provided you ship it back to them on your dime for evaluation if they can't find your purchase receipt record.

Helps cut down on the "free for life" battery / warranty scammers which drive up the costs and reduces warranties for the rest of us.

It's a bummer, but that's part of the reason why some batteries cost more.

 

[Substrate]

Here's the manual in case some have gotten this second hand and want to attempt revival - there seem to be a few different way of recovery and possible clues for previous owner abuse.

https://www.renogy.com/content/RBT200LFP-BT/RBT200LFP12-BT-G1_manual_V1.0.pdf

hth ..

 

[mayuan]

I also had similar issue on the battery. Here are some pics of the inside of the battery