Frustrated and need ideas…

InMyImage

Solar Enthusiast
Joined
Nov 17, 2020
Messages
110
I have 8 Lishen 272ah cells and 2 Daly 250amp “Smart” BMS’s

Initially I’m focused on making 1 12v battery pack and then once I know more about how it is going to behave, I’ll build the second one.

On these cells the Black terminal is positive and the white terminals are negative, white heat shrinked balance wire is the first cell negative.

I have my cell busbars and balance wires connected as:

image.jpg

Each cell’s individual voltage is approximately 3.285v

Total bank is 13.06v

When connecting the Daly BMS I do the following
Connect balance wires
Connect Bluetooth to UART plug
Connect temperature probe
Connect Blue BMS Negative to battery main negative
Short Load negative with battery negative, unlike Will I used the load negative wire lug to the main battery negative terminal.

When shorting the BMS nothing happens to give any indication that the BMS is live.

When I test after connecting everything I get the following voltages
Main positive directly to main negative : 13.06v
Main positive to BMS battery negative : 13.06
Main positve to BMS load negative : 10.25

Nothing appears to go live with the bluetooth

So any ideas? I’ve tried both BMS’s and the result is the same.
 

Diysolar123

Solar Addict
Joined
Feb 28, 2021
Messages
642
well, I have used a daly 24v and never had to "short" anything to have it work.
in order to take bluetooth out of the equation for trouble shooting I always just use a serial port connection; you should just need 3 wires, gnd rx, tx.
Watch for clone serial chips as that can cause all kinds of headaches sadly; I always bought mine from adafruit.com or digikey.
 

time2roll

Photon Sorcerer
Joined
Mar 20, 2021
Messages
2,184
I would try charging the battery through the BMS. Can you post a picture of the BMS connection and the charger/load connected?
 

Diysolar123

Solar Addict
Joined
Feb 28, 2021
Messages
642
I would try charging the battery through the BMS. Can you post a picture of the BMS connection and the charger/load connected?
good idea and if you have a clamp-on ammeter you could see if current is flowing into the battery...
The down side is if nothing happens it "could" just be that the bms has turned off the charging fet, which of course you cannot see without connecting to it hehe
 

macdad22

New Member
Joined
Apr 11, 2021
Messages
11
You have to wake your BMS. You can do this by charging your battery, for lifePO 14.4V is recommended by anything above 13.06V should work. If you do not have a charger you can short B- to the P- on the BMS. Most of us do this my switching our multimeters to Ohm mode. This shoudl wake up the BMS and bluetooth device.
 

InMyImage

Solar Enthusiast
Joined
Nov 17, 2020
Messages
110
I wasn’t sure if I should try to charge it not know what state the bms is in or if i would be able to get any data from it.

I shorted B- to P- because it is what Will has demonstrated as how to wake up the BMS during his build videos but I realized that he never says how he knows it is actually working before he does anything with it.

I also have the USB monitor cable but don’t ise my laptop mich and can’t find my charger.

We are full-time RV’ers and are waiting on that new Victron Charger/Inverter for RV’s to arrive, it’s already paid for and will hopefube here by the end of July.

For now as a workaround, we have a charge wizard converter/charger in the RV that we can manually set to charge at 14.4v for up to 6hrs. The desulfation stage only kicks in if it hasn’t drawn anything from the battery in 30 hours.

I’ll post an update after I’ve been able to hook it to the charger for a while. Unfortunately I have a really basic digital multimeter so I’ll have to just manually monitor it if the BT doesn’t wake up.
 

InMyImage

Solar Enthusiast
Joined
Nov 17, 2020
Messages
110
Thanks guys, after disconnecting our FLA’s and hooking it up to our RV, connect the balance cables and initiating the boost charge in our charge wizard everything appears to be working including the bluetooth. Now just need to dig into the parameter settings.
 
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