How to tell if BMS Dead or working? [DALY BMS 4S 12V 100A - COMMON PORT]

Joined
Sep 15, 2021
Messages
1
Quick Specification:
BMS
: [DALY BMS 4S 12V 100A- COMMON PORT]
WIRE SIZE OF BATTERY: AWG #6 PV CABLE
BATTERY TYPE: LIFEPO4
BATTERY BRAND: CALBLIFEPO4 12V 100AH
BATTERY CONNECTION: SERIES EACH CELL IS 3.2Volts

Problem: Not sure if the battery or BMS is defective

Screenshot of Diagram from Daly BMS:
DALY BMS DIAGRAM.jpg

Screenshot of DALY BMS:
DALY BMS TYPE.jpg
Screenshot: (Tester direct P- and B+ of BMS)
-
in this screenshot I connected my digital tester's negative and positive to the -P (Main negative of BMS) and B+(Main positive of BMS). Voltage shows 10Volts only.
IMG_20210914_180924_1.jpg


Screenshot: (Tester direct to Battery)

- In this screenshot, I bypassed the connection of BMS. I connected my tester directly to the main negative and main positive of my battery to check voltage. Results show it is 13Volts.
IMG_20210914_180821.jpg

Screenshot of SRNE MPPT CHARGER 40AMPS:
- I tried connecting it to my MPPT solar charger but my charger cant recognize my battery. Same with my inverter it won't turn on since it cannot recognize the battery.

FYI, ERROR 015 Means there's an anomaly in battery system.
IMG_20210916_062644.jpg

Disclaimer: I'm a newbie on solar installation. So feel free to comment or make a suggestion.
 

rickst29

Solar Addict
Joined
Mar 27, 2021
Messages
558
Location
Reno, NV
Every MPPT charger which I am familiar with requires that the battery leads (including the negative bus with Daly P-) be connected before the Solar leads. However, the BMS has very high resistance between B- and P- until the BMS experiences actual charging. So the Solar Controller doesn't see an adequate and valid battery, and might not have enough energy to run its MPPT charging circuitry.

You will need another apply another charging method, in order to get the Daly "activated". You should first disconnect the "P-" power connector from your battery grounding bus. Then disconnect the balance wires connector from the Daly for about 10 minutes. (That leaves it unpowered, and it will re-initialize when you plug things back in.) You can leave B- and the temp sensor attached. Be sure that your temp sensor is plugged in, nothing works without the temp sensor.

Then, plug in the 5-pin header for the balancing wires. Resistance between B- and P- should fall to nearly zero - but if it doesn't, there are still two more ways to force activation: You can add a basic 14.6V "LFP charger" brick on the battery terminals, and everything should come up pretty fast. Or, you can attach one of the UART devices (the PC cable with a PC, or the State-of-Charge LCD monitor). I have used both methods with success. See this for full instructions: https://diysolarforum.com/resources...to-attach-daly-smart-bms-to-4s-batteries.180/

The UART method is more certain to work on the first try. Daly sells the SOC monitor UART attachment separately, on one of their EBay stores. The monitor is not accurate, but it's great for assuring the Daly never sleeps (if you leave it plugged in all the time). That does create a noticeable phantom load, but your Solar should take care of it easily.

Some people have also shorted between B- and P- to "get it going", but I don't like that method - As their instructions try to describe (#4, in which you're checking resistance), they will void your warranty if they hear that you have "fused" B- to P-.
 

TLJester

New Member
Joined
May 24, 2020
Messages
41
Just found this.
Mines doing the same.

Daly 48v 250amp NON-SMART BMS
From bank + to - i read 53v
Yet from bank + to BMS - i only read 9v


Just to confirm this is ok to do with a 48v bank?
"wake up trick" :
Once every now and then I have to short out the B- and P-. I do it momentarily. A fraction of a second with a wire.
This has helped to "start" the BMS for me when nothing else will.
Hope this helps. :)
 

TLJester

New Member
Joined
May 24, 2020
Messages
41
Actually i got it working.
Pulled the balance cable and test each line to the black. All correctly setup, and incremented from 3v to 52v
Plugged it back into the BMS and retest - BOOM ! Not literally but i do have 52v out of the BMS now :D
 
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