Voltage drop at Daly BMS 4S 12V 200A Lifepo4

[HBK1]

I measure the voltage drop directly at the BMS between B- and P- with nothing else in between.
If I discharge less than about 7.7A from battery then the BMS have just 3 mV voltage drop between B- and P-.
If I discharge more than 7.7A then there is a voltage drop of 0.6V between B- and P-.
This looks to me that the MOSFET for some reason is not working properly.
I also see that when I discharge 10A the BMS display discharge of 36A so the Current and SOC is in complete error.
I use BmsMonitor V1.2.8 and I do not find any parameters that seems to be wrong.

Daly BMS 4S 12V 200A Lifepo4
R05W-GF24
SW version:20210520-3031A
HD version:DL-BMS-R05-01E

Daly support only answers irrelevant parameter changes and does not acknowledge the problem.
Anyone with the same bahavior or have a clue about the solution to the problem?

 

[M'Enfin]

I have similar problem

200amp 4 cells Chinese LFP
4s 12v 250amp BT Daly BMS, bought June 2021
220/12v charger set on LFP
Battery charged at 12.9

I have 14.1 out of the charger
I have 14.1 in the Daly
I have 12.9 out of the Daly

Impossible to have the Daly app functioning
The app doesn't see the Daly

I'm busy about this since June with Daly

They gave me different solution. None are working.

Last one: buy their power meter

Obviously it's a technical issue

3 hours ago, I ask for refund, they did not appreciate

Still waiting for Daly next solution

 

[HBK1]

The voltage drop is because the MOSFETs are switching off without any notice.
The problem is that Daly BMS is not tolerant towards disturbances coming from other units connected to the same 12V.
By using some capacitors and ferrits I was able to make the problem disappear.
Daly should really consider to review the construction of the gate circuit of the MOSFETs, it is way too simple to disturb and I can not trust a 200A unit that is so easy to disturb.
The inverter used to put load on the BMS was the source of disturbance and is the one I am using in my Camping Car and is much more expensive to replace than the Daly BMS.
Since there is no direct fault at the BMS I can not claim warranty but simply have to buy a BMS of better quality and it will not be a Daly.

Daly support was at no help at all!

 

[Just John]

I have similar problem

200amp 4 cells Chinese LFP
4s 12v 250amp BT Daly BMS, bought June 2021
220/12v charger set on LFP
Battery charged at 12.9

I have 14.1 out of the charger
I have 14.1 in the Daly
I have 12.9 out of the Daly

Impossible to have the Daly app functioning
The app doesn't see the Daly

I'm busy about this since June with Daly

They gave me different solution. None are working.

Last one: buy their power meter

Obviously it's a technical issue

3 hours ago, I ask for refund, they did not appreciate

Still waiting for Daly next solution

The Daly has a common problem of not activating, the fact you can't see it with the app over Bluetooth indicates it's not activating.

They change models and pinouts frequently, but this might help.

More DALY smart BMS issues

Here you go, I took pictures of waking up my 250 smart bms. First picture is just fresh after hooking it up. not yet woke up. Then I short momentarily these 2 pins. Then I remeasure the voltage afterwards and it's now awake.

diysolarforum.com

I even have some links to connectors and switches on Amazon to build your own wake-up switch. Daly is probably correct about what you need, their power meter includes a reset switch.

 

[Dan Vezina]

Bluetooth timeout can be quickly fixed setting it to 15300 or 65535 in Cell param menu.
see post: https://diysolarforum.com/threads/400a-daly-bms-not-turning-on.21843/page-2#post-301755

 

[Just John]

Bluetooth timeout can be quickly fixed setting it to 15300 or 65535 in Cell param menu.
see post: https://diysolarforum.com/threads/400a-daly-bms-not-turning-on.21843/page-2#post-301755

Yes, first you have to activate and connect to it to be able to set anything.

 

[Dan Vezina]

Yes, first you have to activate and connect to it to be able to set anything.

I agree,
1 disconnect all load and charge,
2 disconnect battery monitor and wait 1 min (5 wires monitor)
Check that BT module connected to BMS.
3 reconnect battery monitor cable
4 Connect any form of charger (Volt must be cell upper limit x cells unit) ex: 4s lfp 12v (3.6 x 4) 14.4v
If charger is lower than battery state, use a 1.5v battery AA cell in series to kick bms on (max 15V)
5 BMS and BT shall come ON.
If this step process does not work you may have other issue with BMS.

Note from above post; battery at 12.9v is a discharged unit.

 

[Just John]

I agree,
1 disconnect all load and charge,
2 disconnect battery monitor and wait 1 min (5 wires monitor)
Check that BT module connected to BMS.
3 reconnect battery monitor cable
4 Connect any form of charger (Volt must be cell upper limit x cells unit) ex: 4s lfp 12v (3.6 x 4) 14.4v
If charger is lower than battery state, use a 1.5v battery AA cell in series to kick bms on (max 15V)
5 BMS and BT shall come ON.
If this step process does not work you may have other issue with BMS.

Note from above post; battery at 12.9v is a discharged unit.

Common Daly BMS problems?

I'm starting this thread to help people figure out some of the most common Daly BMS problems. Please feel free to add additional solutions. First I'm going to copy a post I've already made, with some additions. 12v "Smart" BMS: 24v "Smart" BMS lightboard: For the 12v model, you can...

diysolarforum.com

Feel free, it's a month old as well.