Chargery BMS not detecting charge

[peteappleyard]

Hello, I'm wondering if some of you knowledgeable folk can help me out...

I've tried searching the forums but can't find anyone else who's had this issue, so apologies if I've missed an answer.

So I've recently bought the Chargery BMS after reading recommendations on the forum. I'm using 4x 280Ah EVE cells to create a 12v battery. I'm using the 300A shunt that came with the Chargery and 2 solid state relays (the 220v DC 600A ones here: https://www.aliexpress.com/item/4000136607816.html?spm=a2g0s.12269583.0.0.26b67126OfTKd8)

I set up the batteries, top balanced them, then installed the BMS (powered internally from the cells, rather than external power) and shunt etc. Discharging works fine and I powered my inverter for ages and the BMS display showed a discharging current. My main issue now is that I've come to charge the batteries and the BMS isn't showing any charge going in to the batteries. The charger is definitely connected and working and the bms DOES show the individual cell voltages and overall battery voltage going up as the system charges. However, the display is stuck showing 22% state of charge and the Wh and Ah values are stuck too. I assume these values aren't changing because the shunt isn't detecting the charge going in to the battery?

I'm running BMS version v4.04 and I also have the issue as someone else did, of the unit displaying 0 for 'the internal R when cell in use'. I've tried cycling the power on the BMS. I haven't calibrated for the shunt as the Chargery says that if you use the supplied one, this isn't necessary. I followed Will's Youtube video to get it set up, and have ran through the instruction manual too, but I can't see that I'm doing anything wrong.

I've now stripped my system right back down to eliminate elements. My current temporary setup for testing is:

Charger neg > shunt > - Battery + < fuse < charger pos

As you can see, I've taken the relays out as well as any loads etc, still to no avail.

I'm really hoping that there's a setup step that I've missed or something, rather than it being a faulty unit. As I said, it worked with discharging perfectly.

Any help VERY much appreciated.

All the best,

Pete

 

[Steve_S]

Will's video on Chargery is USELESS... plain and simple, he got frustrated doing something he did not have to, did not read the updated docs, and got himself into a tizzy.. rather than step back, take a breath and READ the correct manual docs, his emotional angst took over and he brain blocked.

Looked the link provided for those SSR's, they appear to be UNIDirectional, One Way Only and not surprising because they are so cheap. Bi-Di ones are Much more costly. Also their terminals (or lack of) is a RED Alert that they are unsuitable for this purpose. How can anyone attach real battery cables to screws like that, 2/0 - 3/0 wires with 3/8" (10mm) lugs on those ?

From Batt:
(NEG) to Shunt, from shunt to Busbar or Inverter
(POS) to Fuse, to Relay(s)/Contactors to Busbar or Inverter.

Contactors (SSR & Mechanical) can be either Uni-Directional or Bi-Directional.
Unidirectional is only serviceable with a Separate-Port Installation as Charging is only One Direction in-bound and Discharging is only One Direction outbound.
Bidirectional is required in Common-Port as energy travels in both directions through the relay/contactor.

 

[Bob B]

If you are trying to charge when bypassing the SSR, it isn't the SSR causing the problem. Have you verified what the charge current actually is with a clamp meter or meter in series with the charge circuit?
Please let us know what the actual charge current is.

Another simple test would be to run the system with a discharge current .... and see what it is reading on the BMS ..... then reverse the shunt leads and see if it changes to indicate a charge current.
Leave the leads reversed and connect your charger and see if you read a load current .... Then return to normal. Let us know the result of that.

If there still isn't any charge current I would send Jason an email and see what he says .... You may have no choice but to try to do a calibration, but I wouldn't do that til I talked to Jason.

 

[Steve_S]

PING @Chargery to call his attention to this thread.

 

[peteappleyard]

Hello guys, thanks for your replies.

@Steve_S Thank you for your comments. The SSRs definitely weren't expensive ones, but I'm not going to be pulling a huge amount of current through my system, so hopefully they should work alright. I'm aware that they're unidirectional and had them set up the correct way around. I'm using 2 in the separate port configuration. The issue is more with the shunt/BMS than the SSRs.

Thank you also for confirmation of the circuit - this is exactly what I'm doing so that's good to know

@Bob B Thank you also. As you state, I've bypassed the SSRs to confirm they're not the issue. On working through your questions...

1. The charge from the charger is 8.7A
2. I tried putting a load through the shunt (it read -4.3A) and then reversing the shunt leads and then powering off/on the BMS. On applying the exact same load, the BMS doesn't register anything is happening (it stays in STORAGE mode).
3. I then turned on the charger (with the shunt leads still reversed, and it reads -8.7A (as if it's discharging)
4. I then put the shunt leads the correct way and applied the load and it again read -4.3A
5. With the shunt leads the correct way around and the load still on, I turned on the charger and the display changed to 0A STORAGE. So rather than going up 4.4A (-4.3 load and then a 8.7A charge) it seemed to not recognise a charging current.

@Chargery do you have any ideas? Shall I try doing the shunt calibration?

Thank you again guys

 

[Bob B]

Never heard that one before. Did the Chargery come with 4.04 or did you update it?

I'm thinking it would be worth trying to reset default and see if things are the same. When you connect the SSRs are they both energized?

I was thinking that if the Chargery had a fault that was disabling charge ... maybe it won't read a charge current even if connected directly to it ..... I don't know that would be the symptom or not.

It is Chinese new years now and Jason is probably out for a while.

 

[peteappleyard]

Never heard that one before. Did the Chargery come with 4.04 or did you update it?

I'm thinking it would be worth trying to reset default and see if things are the same. When you connect the SSRs are they both energized?

I was thinking that if the Chargery had a fault that was disabling charge ... maybe it won't read a charge current even if connected directly to it ..... I don't know that would be the symptom or not.

It is Chinese new years now and Jason is probably out for a while

Thank you for the reply

Yes, I updated to 4.04 when I received the BMS.

I have tried resetting but that hasn't seemed to have made a difference. And yes, when the SSRs are connected, they are both energised.

If I do a shunt calibration anyway, is it going to cause any issues?

 

[Bob B]

Thank you for the reply

Yes, I updated to 4.04 when I received the BMS.

I have tried resetting but that hasn't seemed to have made a difference. And yes, when the SSRs are connected, they are both energised.

If I do a shunt calibration anyway, is it going to cause any issues?

I don't think doing a calibration could make things any worse ..... just need to make sure you have a VERY accurate way of controlling either charge or load current ... and follow the procedure in the newest manual exactly.

I was recommending hold off doing the calibration just for warranty considerations .... but I think you have documented your problem on here well enough that Jason shouldn't have a problem with you having tried that.

Hope it works for you.

 

[Daddy Tanuki]

@peteappleyard any updates on this? thanks.