Chargery 8T disconnecting discharge bus

[mkaye]

i installed a balancer and missed the ground connection for the external power to the BMS
BMS still worked as it was finding ground on the sense leads
reconnected missing lead
issue is, i turn on my converter and BMS opens the discharge relay within 2s (before & after missing lead)
converter is connected to discharge bus @ dc distribution panel
ran temp wire from converter to charging bus (not connected to discharge bus) - no change
converter supplies about 30A
i had all my solar connected and the alternator yesterday and had 35A - so i don't think it is an overcurrent issue
i watch the cell voltages when i turn on the inverter and they don't change - <10mV difference
since it is opening the discharge relay it must think there is some issue with low voltage
i am going to do a factory reset and reload the firmware
balancer is disconnected doing all this

factory reset/reload firmware - same issue

charging with solar now 16-20A, no issues

 

[Bob B]

We are probably going to need some screen shots from the Chargery while the problem is occurring.

 

[mkaye]

it's too short
i power on the converter
i am watching the cell balance screen
nothing changes, but the discharge relay opens, shutting down my converter and inverter
charging continues
they fire back up and will go through the cycle again until i flip the breaker to the converter

i just noticed that the discharge relay also opened when i was charging and the cells went >150mV out of balance
should this have been the charging relay
could i be so dumb to have the relays wired backwards?

 

[Bob B]

it's too short
i power on the converter
i am watching the cell balance screen
nothing changes, but the discharge relay opens, shutting down my converter and inverter
charging continues
they fire back up and will go through the cycle again until i flip the breaker to the converter

i just noticed that the discharge relay also opened when i was charging and the cells went >150mV out of balance
should this have been the charging relay
could i be so dumb to have the relays wired backwards?

You can test that by temporarily lowering the over charge voltage settings lower than the current pack voltage .... lower the return setting first ... then the P setting.
Do the reverse when returning them to normal .... raise the P setting first.

 

[Steve_S]

Silly Question: Are you sure the Relay/Contactors you are using are Bi-Directional ?
Mono-Directional is FINE but has to be wired accordingly if using a separate charge line.

 

[mkaye]

problem solved by setting max charge current on my Chargery BMS to 140A from 70A even tho max from PD4655 is 55A
only ever saw 35A
must be a spike when i turn it on

 

[mkaye]

no, not fixed
battery down to 85%
turned on converter & the BMS shut down the discharge bus
only saw 35A
changed max charging current to 195A
let it cycle a couple of times
finally turned it off
if it was an overcurrent problem it should cut off the charging bus, not discharge

Silly Question: Are you sure the Relay/Contactors you are using are Bi-Directional ?
Mono-Directional is FINE but has to be wired accordingly if using a separate charge line.

have small auto relays controlling large 300A mechanical relays

 

[mkaye]

Moved jumper on converter to FLA – 12A – seemed OK for a few minutes

Installed jumper for AGM – 20A+ – fails

Back to FLA – OK

Pushed charge wizard button to kick voltage up to 14.6V, 25A+ - fails

Have to wait for charge wizard to expire after 4 hrs…

Seems to be the sudden jump to 20A+

The solar & alternator are through the Renogy DC-DC charger & it ramps up more slowly to full current, which i have had at 35A+ with solar & alternator

That’s the only difference I can see