Batrium Watchmon5 question

Announcement - Help us fight the BOTS! Please report all spam including stuff in your inbox!

w0ss

Member
Joined
Oct 15, 2019
Messages
56
I am having an odd issue and I am trying to figure it out. When the WM5 goes into bypass some of the cells will read very high for a second or two. Jumping from 4.10 to 4.2 or 4.3 I don't understand how this could happen. If anything I would expect the voltage to drop as it is bypassing .5 amps. a 189ah cell is obviously not going up and down 2/10's of a volt in a second unless it was on fire, I would ignore it as a faulty reading but it is causing my inverter to go into protect mode as the Batrium is sending it the alarm.

Any thoughts or has anyone seen this?
Thanks,
Will
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,666
Contact batrium.
 

Tentious

New member
Joined
Sep 24, 2017
Messages
7
I had this problem when I connected the cellmons to wire lead extensions connected to the cells instead of batriums requirement of being directly connected to the cell. I think the extra wire resistance throws the cell voltage calculation off. I ended up connecting much larger guage lead wire than the provided leads will accommodate, I think it was 10 awg wire for extending the wire. After increasing the wire size of the extension, voltage readings of adjacent cells to the cell in bypass are now accurate and they don't also go into bypass because of incorrect higher voltage.

Hope this helps.
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,666
That generally only lower the voltage and doesnt raise it but its a valid sugestion.

If you dont use original wiring and length you dont have any support from Batrium in terms of error. So that need to be considered. The longmons have an impedance matching in the leads.
 

w0ss

Member
Joined
Oct 15, 2019
Messages
56
I will try Batrium again. I agree if it was an issue with wiring voltage should go low not high but perhaps there is something else going on.
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,666
Have you fiddled with the wires at all?
 

Tentious

New member
Joined
Sep 24, 2017
Messages
7
I also agree that the voltage would appear to go down with the current draw from the cellmons, but for some reason, it caused my adjacent cellmons to rise in voltage only when in bypass.
 

w0ss

Member
Joined
Oct 15, 2019
Messages
56
Daromer, yeah i have redone the cabling a few times and the issue persists. not saying it isnt the cabling but still investigating.

Tentious, Interesting as this is on a Watchmon5 which is designed to work on shared wiring looms.
 

Tentious

New member
Joined
Sep 24, 2017
Messages
7
w0ss, you're correct, I have watchmon 4, so I guess my comments are not valid as long as the balance lead wires are within spec(length and gauge). I'd also contact Batrium for support, they are generally pretty quick to respond.
 

daromer

Moderator
Joined
Oct 8, 2016
Messages
5,666
Ah yeah wm5 and 4 works differently in how they meassure. WM5 meassure every 2nd at a time with integrated chipset. It sounds weird it raises but i have not used the 5 enough to say anyting more than Batrium have showed.
 

w0ss

Member
Joined
Oct 15, 2019
Messages
56
Got a pm from @Angeee but they have their PM's off. Batrium said it's normal and a result of the voltage settling. I don't know that I agree with that... but oh well. I do wonder if they are using a bq76940 because in the TI FAQ they talk about voltage rise. I wonder if they are switching between balancing adjacent cells too quickly.
 

Angeee

New member
Joined
Jun 7, 2020
Messages
1
Hi Will,
sorry didnt even realize i had it off anyways i have a similarissue and im going to try shorter balance leads, another battery and even some ferrite beads on the balance wires and see what it does.

cheers
Ange
 

w0ss

Member
Joined
Oct 15, 2019
Messages
56
I would say reach out to Batrium. Maybe they will realize they have an issue. Or maybe all of us are doing something wrong that they didn't account for and they can help us fix it :)
 
Top