MorganCarey
New Member
- Joined
- Jul 19, 2020
- Messages
- 49
Theoretical scenario.
I have a 110ah drop in replacement lifepo4 battery. On it's spec sheet it's low operating cut-out is 9.6volts. I am assuming in this scenario that the BMS will go into protect(sleep) at 9.5V.
If the battery goes to sleep, I think this may be an issue for my scc. I have a 12/24 volt controller. Normally, when the battery is connected, it sets the system voltage automatically (Tracer 4210an). But if the battery is asleep, the scc wont see any voltage. So I am assuming it wont even turn on to start recharging the battery.
To wake up this battery we have to force feed it current basically? Could a solar panel be temporarily wired directly to the battery for the purposes of waking it up? Once the voltage rises above 9.5V, the BMS will come out of protect, at which point the scc will power up and set the system voltage to 12v to facilitate charging.
Chicken and egg scenario??????
I am envisioning a manual transfer switch between my combiner box and charge controller that will divert the panels directly to the battery in this extreme case. The voltage would be monitored and once it rises to the point where the BMS is happy, the transfer switch would be switched back to the normal operating position and pass current to the SCC.
Yes I have a LVD that is set above that threshold of 9.6v anyways, but that is only protecting the battery from the DC/AC inverter. The shunt and LVD are drawing power from the battery still. If one malfunctions it could conceivably take me to 100%DoD. Alternatively if there was a lightning storm and a voltage spike blew some fuses in my combiner box, the SCC would eventually take the battery down also.
This may sound like overkill, but the system runs at a shared family cottage and most of the family members that utilize it wouldn't have the first clue on how to troubleshoot manually. Complicated by the fact that it's a 6 hour drive into nowhere land, it's not like I can swing by on a whim and break out the meter.
I'm trying to make a setup that I can walk a family member through on the phone and give them a potential bail out ...... ie, "check breaker #4" "move the transfer switch for 30 minutes and monitor voltage and call me back" etc etc
So ya, TL;DR. Can a solar panel (12V) be wired directly to battery to bring it online again?
I'm asking this because I'm in the process of rewiring everything, and can easily add this in now to my redesign, if it would work.
thoughts?
I have a 110ah drop in replacement lifepo4 battery. On it's spec sheet it's low operating cut-out is 9.6volts. I am assuming in this scenario that the BMS will go into protect(sleep) at 9.5V.
If the battery goes to sleep, I think this may be an issue for my scc. I have a 12/24 volt controller. Normally, when the battery is connected, it sets the system voltage automatically (Tracer 4210an). But if the battery is asleep, the scc wont see any voltage. So I am assuming it wont even turn on to start recharging the battery.
To wake up this battery we have to force feed it current basically? Could a solar panel be temporarily wired directly to the battery for the purposes of waking it up? Once the voltage rises above 9.5V, the BMS will come out of protect, at which point the scc will power up and set the system voltage to 12v to facilitate charging.
Chicken and egg scenario??????
I am envisioning a manual transfer switch between my combiner box and charge controller that will divert the panels directly to the battery in this extreme case. The voltage would be monitored and once it rises to the point where the BMS is happy, the transfer switch would be switched back to the normal operating position and pass current to the SCC.
Yes I have a LVD that is set above that threshold of 9.6v anyways, but that is only protecting the battery from the DC/AC inverter. The shunt and LVD are drawing power from the battery still. If one malfunctions it could conceivably take me to 100%DoD. Alternatively if there was a lightning storm and a voltage spike blew some fuses in my combiner box, the SCC would eventually take the battery down also.
This may sound like overkill, but the system runs at a shared family cottage and most of the family members that utilize it wouldn't have the first clue on how to troubleshoot manually. Complicated by the fact that it's a 6 hour drive into nowhere land, it's not like I can swing by on a whim and break out the meter.
I'm trying to make a setup that I can walk a family member through on the phone and give them a potential bail out ...... ie, "check breaker #4" "move the transfer switch for 30 minutes and monitor voltage and call me back" etc etc
So ya, TL;DR. Can a solar panel (12V) be wired directly to battery to bring it online again?
I'm asking this because I'm in the process of rewiring everything, and can easily add this in now to my redesign, if it would work.
thoughts?