DALY BMS not charging

[mihastare]

I have Smart DALY 200A BMS working flawlessly for 3 years now, but now it started to act strangely.
I have this one: https://www.amazon.com/gp/product/B08PFNCNLR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

It doesn't let trough charging current. Or better say - sometimes yes, sometimes no
Discharging works without any problem all the time.

Yesterday it was all day sunny, but without any charge. It stayed on 76%. Later that day it started to charge for few hours until it got dark. I got to 90%, but today it's again at 80% and not charging under the sun. Sometimes it charge, sometimes it doesn't.

As you can see, there is no error - "Status information 0" and "Chg MOS" is ON, but still it doesn't let it trough.

I tried changing High volt protection to set higher V without success.

I tried System reset but no luck.

Is there any other way to deep reset it?

 

[Texas-Mark]

You have the sum high voltage set to 13.8v which IMO is a bit low (I have mine at 14.4v). And the Daly BMB SOC needs to be manually "reset" too every once in a while to 100% because it is not super accurate (especially if bluetooth is set to stay on a long time).

 

[mihastare]

I did set it to 14,5V but the problem is still the same.

I know SOC needs to be reset from time to time. I do that.

But this time the battery is actually NOT full. Yesterday it started charging at 70% and than charging until 90%.

Today it is hanging at 80% on a sunny day. And also with a 220V charger plugged.

 

[Texas-Mark]

Today it is hanging at 80% on a sunny day.

What do your cell voltages read when charging stops?

 

[mihastare]

Today it has been charging up to 3,35V per cell.

Settings today I'm testing are:
3,65V and 14,5V (limits).

And it just cuts of charging now at 13,4V SUM and 3,35V/cell

 

[Texas-Mark]

What are you using to charge it? Perhaps the charger is what is cutting off too soon. Or are you saying it actually shows the charge MOS opening? If so, then it should be giving you a fault in the status area.

 

[mihastare]

Exactly!

It is showing me Chg MOS open, but does not accepting charge and WITHOUT showing any fault in status area.

But I just discovered another issue probably showing that BMS is really going wild.

On one side of BMS (BLUE cable - IN) is 13,2V.
On another side of BMS (BLACK cable - OUT) is 12,56V.

This means I should buy a new BMS ASAP?

 

[Texas-Mark]

This means I should buy a new BMS ASAP?

I would at this point. Might try a factory reset first just for the heck of it.

 

[mihastare]

Factory reset is unplug cell wires and C- and P- for 1 minute?

 

[Texas-Mark]

Factory reset is unplug cell wires and C- and P- for 1 minute?

No, I think it's done in the app.

 

[mihastare]

It gives me This feature is not available yet :D

Now I'm looking which BMS to buy - JK or JBD.
JK has more recommendations, but JBD has so much better mobile app in my opinion :/

 

[markcm]

I am having the same issue with a DALY 100A BMS no longer allowing charge current into the battery. I've installed it in a battery I built for my RV about 1.5 years ago. It has worked flawless until we camped this weekend.

Nothing has changed in my setup, it just stopped charging. I've tried a reboot, I've turned the charge and discharge MOS off and back on... still no charging.

I also have a 1v lower reading on my BMS (BLACK cable - OUT) vs my BMS (BLUE cable - IN). I never checked the drop across the BMS before when it was working, can anyone check a working DALY and confirm what the drop is across the (-) through the BMS?

I also notice the setting for MOS temperature is showing "--", I don't know if that used to show a valid temp or not.

 

[Texas-Mark]

I also notice the setting for MOS temperature is showing "--", I don't know if that used to show a valid temp or not.

FWIW, mine does (100A version). Probably the problem with yours.

 

[rbeudel]

take a look to the thermo sensor. If it is broken, the bms will not play.

 

[markcm]

take a look to the thermo sensor. If it is broken, the bms will not play.

Thanks for your comment.

My external thermocouple is in good condition, working and reading correctly although it seems there is an internal "MOS" thermocouple that may have failed on my BMS as it's reading is "--". Unfortunately when I inquired with DALY, they responeded with a generic sales biased message. While I am the DIY type, I don't think I will be trying to open up this 12v 4s 100A "waterproof" BMS assuming it is potted and I also don't want potentially compromised electronics in my camper trailer.

 

[Checkthisout]

My Daly BMS also failed. I replaced it with a JK bms albeit there are others like JBD that are supposed to be good as well.

I wouldn't bother trying to troubleshoot when it starts acting weird.

Just throw it in the garbage and don't look back.

 

[markcm]

Thanks for your comment.

My external thermocouple is in good condition, working and reading correctly although it seems there is an internal "MOS" thermocouple that may have failed on my BMS as it's reading is "--". Unfortunately when I inquired with DALY, they responeded with a generic sales biased message. While I am the DIY type, I don't think I will be trying to open up this 12v 4s 100A "waterproof" BMS assuming it is potted and I also don't want potentially compromised electronics in my camper trailer.

Here's some interesting info in this issue-

I bought a replacement, same 12v 4s 100A DALY smart BMS and it also reads "--" for the MOS temperature. But the replacement will accept a charge. So apparently this model doesn't have or use a MOS temp sensor but my original unit, although the app said the charge MOS was on, and I could switch it on or off, it would not accept a charge.

 

[mihastare]

My old DALY also didn't show MOS temp from day 1. So that shouldn't be an issue.