I think I'm doing something wrong

[igorscheffer]

I connect the wires to the battery, the computer does not connect the battery, no LED lights up while it is connected even if I press the button

[Tool-Scientist]

Get a multimeter amd measure voltages from B- to J1 (next to B+) and J2 (near B-).

Do:

• m.idle(): J1 < 1V, J2 < 4V
• m.high(): J1 > 2V, J2 > 8V

If you're not getting those voltages, then communication won't work.

[igorscheffer]

[igorscheffer]

This battery may have a problem because when I click the button it starts flashing. When I put it on the charger it charges for a few seconds then the light turns green indicating that it is charged. When I take it off the charger the charge indicator is complete after a few seconds I click it again and it starts flashing again.

[Tool-Scientist]

Your circuit board is from 2015, it may not have diagnostics. What happens when you do m.simulate()

[igorscheffer]

Your circuit board is from 2015, it may not have diagnostics. What happens when you do m.simulate()

the battery says it would be 2020/10

[igorscheffer]

Your circuit board is from 2015, it may not have diagnostics. What happens when you do m.simulate()

[mnh-jansson]

If the LED indicator is flashing, verify voltages on:
Main terminals (Bat + , Bat -)
Cell connections (Measure on PCB, break can be hiding in the nickel strips)

Measure resistance of the temperature sensor.

[igorscheffer]

If the LED indicator is flashing, verify voltages on:
Main terminals (Bat + , Bat -)
Cell connections (Measure on PCB, break can be hiding in the nickel strips)

Measure resistance of the temperature sensor.

Measuring B+ and B-, it's 15.8V. Measuring the solder points on the BMS, each pack gives 4V. I'll get another battery to test. I just need to wait for another FTDI to arrive. I fried mine along with the laptop's USB ports.

trim.BF8D0151-E199-4F1C-9CA2-86B5CDF19BA7.MOV

[jessevallaro]

I am having the exact same issue, no light on the battery

Using these boards:

• https://www.sparkfun.com/sparkfun-logic-level-converter-bi-directional.html
• https://www.sparkfun.com/sparkfun-serial-basic-breakout-ch340c-and-usb-c.html

Can verify that m.idle() and m.high() do make a difference, tested voltage via multimeter on the serial adapter. When idle pressing button on battery shows voltage, when high battery does not respond to button press, no lights or charging indicator either.

Battery is M18 Red Lithium with a date code ( I believe that's what it is): 240920

[Tool-Scientist]

@jessevallaro

Connect adapter to battery then measure voltages between B- and J2 (next to B-) and J1 (next to B+). Then use the m.idle() and m.high() commands.

You should see:

• m.idle(): J2<1V, J1<1V
• m.high(): J2>8V, J2>2V

I get:

• m.idle(): J2=0.13V, J1=0.81V
• m.high(): J2=8.8V, J1=3.3V

[jessevallaro]

Sorry, but I do not know what B- and J2 refer to. Are they terminals on the battery or internal? None of my batteries are open if these are on the bms board.

[Tool-Scientist]

Yes, they are terminals on battery.

See updated wiring diagram (may need shift+refresh to clear cache).
https://github.com/mnh-jansson/m18-protocol/blob/master/docs/wiring.png

[mnh-jansson]

If the LED indicator is flashing, verify voltages on:
Main terminals (Bat + , Bat -)
Cell connections (Measure on PCB, break can be hiding in the nickel strips)
Measure resistance of the temperature sensor.

Measuring B+ and B-, it's 15.8V. Measuring the solder points on the BMS, each pack gives 4V. I'll get another battery to test. I just need to wait for another FTDI to arrive. I fried mine along with the laptop's USB ports.

trim.BF8D0151-E199-4F1C-9CA2-86B5CDF19BA7.MOV

That's a bit strange. These batteries do not have a cutoff (only on charge pin), so you should see 20V in case every bank is indeed 4V.

[igorscheffer]

@mnh-jansson

my problem was ftdi in the battery reading issue

[jessevallaro]

Yes, they are terminals on battery.

See updated wiring diagram (may need shift+refresh to clear cache). https://github.com/mnh-jansson/m18-protocol/blob/master/docs/wiring.png

Thank you for this!

I get:

m.idle(): J2 = 0.121VDC, J1 = 2.948VDC
m.high(): J2 = 12.65VDC, J1 = 3.284

With J1 being direct to the Serial adapter, I am not surprised to find it at ~3.3VDC during idle. How are you getting <1VDC?