Beware

[ivconic]

I use this.

[Jim in Idaho]

More critically, you have no short-circuit protection. Lithiums can catch fire if short-circuited.

yeah...something to think about.
J

[Jim in Idaho]

I went ahead and rewired mine. Better safe than sorry...as Carl said. Starting unintentional fires is a bad thing....LOL
Jim

[ivconic]

Ivconic, put a series combination of silicon and schottky diodes in series with the dc output to get what you want.

... voltage drop across the diode?

[Mark-VA]

Well I tested the other module and it is malfunctioning too. I ran it for an hour and checked the voltage of each battery. One battery was at 1.5 volts while the others were at 3.1 volt. The module should have shut down the battery pack over that low voltage if it was working properly. That also leads me to believe the short circuit protection is most likely not working either. Still Battery Junction refuses to discuss their web site mistake. I hate it happened to me but maybe someone else might be aware of the faulty information. As a final story, I guess it's always better to seek the manufacturers technical documents regardless of what the item is.

[Jim in Idaho]

Ya know, Mark, when I look at the two sites, I'm not seeing any difference in either the connection drawings, or the connection instructions. Apparently I'm missing something. Never said I was smart...LOL. What I did on mine was my own fault. I made an assumption about where the power out was supposed to be connected. Other than that, I followed BJ's instructions and as far as I can tell it works. I have not tried to charge it since changing the wiring last night. I think I'll get it out and try charging it. I stopped it at 16.0v, but can charge it a bit higher, if it will charge.
Jim

[ivconic]

Only test i did with this BMS, first time i used it; was to monitor it through the volt&ampere meter.
It started with 1.6A and ended with ~70mA at the end of charging. Slowly decreasing, as i checked it all the time.
~70mA stays for long time so i reckon it was some kind of floating charge.
Also could be because i couldn't adjust precisely 16.8V.
After few hours everything remains cool. BMS components and batteries, totally cool.

[Mark-VA]

P-	Output (-) Charger (-)
P+	Output (+) Charger (+)
B+	Battery 1 (+)
B1	Battery 2 (+) and Battery 1 (-)
B2	Battery 3 (+) and Battery 2 (-)
B3	Battery 4 (+) and Battery 3 (-)
B-	Battery 4 (-)

Battery Junction instructions


7 Terminal explanations
7.1.1 B+：Connected to the fourth battery’s positive terminal
7.1.2B3+：Connected to the third battery’s positiveterminal
7.1.3B2+：Connected to the second battery’spositive terminal
7.1.4B1+：Connected to the first battery’s positiveterminal
7.1.5B-：Connected to the first battery’s negativeterminal
7.1.6P+：Connected to the battery’s output or thecharger’s positive terminal
7.1.7 P-：Connected to the battery’s output or thecharger’s negative terminal
Tenergy Data sheet

.B1

B1	Battery 2 (+) and Battery 1 (-)

B1 Connected to the first battery’s positiveterminal

[Jim in Idaho]

What Tenergy did was reverse the numbering order of the batteries. Battery Junction has #4 at the negative end, and Tenergy has battery 4 at the positive end. Definitely confusing.
Jim

[daluka]

Decide, the batteries are connected in series or individually?

[Jim in Idaho]

They're connected in series, but the controller monitors them individually.
Jim

[rickb]

... voltage drop across the diode?

If you have an 18v psu, 2 silicon diodes will drop it to about 16.8 v. If you want a bit more headroom use 1 silicon + 1 schottky for about 17.2 v.