JBD losing voltage across solenoid
- Thread starter wtfg
- Start date
sunshine_eggo
Happy Breffast!
If you apply a charge or a load, does it correct itself?
Yes it just did a charge and voltage is back
It happen at least once a day.
the BMS always shows the right voltage the Victron and my Radian show lower, when its acting up
The Radian wouldn't be charging normally but the voltage drop puts it in charging range
It happen at least once a day.
the BMS always shows the right voltage the Victron and my Radian show lower, when its acting up
The Radian wouldn't be charging normally but the voltage drop puts it in charging range
Adam De Lay
Solar Wizard
I actually had a relay do this on a separate project and the relay proved to be bad.
sunshine_eggo
Happy Breffast!
I don't know why, but I've seen a JBD 200A BMS that drops its apparent voltage every 1097 minutes if left in the same state. Even with a small continuous load of ~50W, it would drop. If the load is changed, or a charge is applied, the voltage immediately rebounds:
RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,565
If drawing any moderate amount of current, a 2.5v drop across the contacts will destroy the contacts in a short amount of time.
Most of the contactor based BMS's back down the coil current after making the switch to ON. This is to save power on the contactor coil which draws quite a bit of continuous current.
Problem with backing down coil current is you also lose hold in force strength on the contacts. Some amount of mechanical shock can bounce the contacts causing arcing and eventually destroy the contacts.
DC current also creates a strong magnetic field close to conductor path. Depending on current flow direction through contacts it can add or subtract to contactor coil hold in force. A large surge current can cause the contacts to bounce at the lower coil drive current.
Sinewave inverters create a 2x AC line frequency ripple current profile on battery DC current. If you hear a 120 Hz buzzing on contacts it is a warning sign there is not enough coil hold in force.
Most of the contactor based BMS's back down the coil current after making the switch to ON. This is to save power on the contactor coil which draws quite a bit of continuous current.
Problem with backing down coil current is you also lose hold in force strength on the contacts. Some amount of mechanical shock can bounce the contacts causing arcing and eventually destroy the contacts.
DC current also creates a strong magnetic field close to conductor path. Depending on current flow direction through contacts it can add or subtract to contactor coil hold in force. A large surge current can cause the contacts to bounce at the lower coil drive current.
Sinewave inverters create a 2x AC line frequency ripple current profile on battery DC current. If you hear a 120 Hz buzzing on contacts it is a warning sign there is not enough coil hold in force.
Last edited:
sunshine_eggo
Happy Breffast!
65000/60 = 1083 minutes, so that's pretty darn close. That might be it. I would try 0 or set it to a larger and see if the behavior changes. I don't have that option on my JBD.
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