The Good Package
New Member
I've built a portable 48v lifepo4 power station with inverter, and I'm looking for the "best" way to charge it from my house 48v bank while parked without having to be paralleled.
Here is initial info / questions / ideas:
- I'll need to frequently "detach" and "reattach" the portable to the main bank for charging and don't want to deal with SOC mismatch, amp surge, etc. Paralleling is not an option.
- While parked, it will be in continuous use running some devices off its own inverter, so charging needs to be fully automated and continuous.
- Grid power is not available.
- The portable has its own separate SCC, but I don't want to have to run a separate PV array to keep it charged. Plus, I'll mainly be reconnecting the portable to the house bank in the evenings, so it would need to charge overnight when PV is unavailable and ready to detach in the morning.
- I'm currently using a standalone AC to DC 10a charger off the house inverter to keep the portable charged. The relay on the portable's Victron BMV-712 is connected to a 40a relay that opens / closes the AC charger's output based on specified voltage. This is working fine, but there are substantial efficiency losses with this method.
- Are 48v DC-DC chargers even a thing? The Victron Orion series seems to be available only in 12v / 24v.
- I know a 48v SCC can't work on its own, but I've seen some inexpensive adjustable DC-DC step up converters that take in up to 60v / 15a and output up to 80v / 10a (some models even higher). Could the output of one of these be connected to the PV input of the portable's MPPT SCC to give it 80v so it can charge the portable? It probably wouldn't charge as quickly, but it would be way more efficient than double AC conversion. Here is an example device: https://www.amazon.com/Booster-Converter-Constant-Current-Voltage/dp/B07KDQ2VY2/
Here is initial info / questions / ideas:
- I'll need to frequently "detach" and "reattach" the portable to the main bank for charging and don't want to deal with SOC mismatch, amp surge, etc. Paralleling is not an option.
- While parked, it will be in continuous use running some devices off its own inverter, so charging needs to be fully automated and continuous.
- Grid power is not available.
- The portable has its own separate SCC, but I don't want to have to run a separate PV array to keep it charged. Plus, I'll mainly be reconnecting the portable to the house bank in the evenings, so it would need to charge overnight when PV is unavailable and ready to detach in the morning.
- I'm currently using a standalone AC to DC 10a charger off the house inverter to keep the portable charged. The relay on the portable's Victron BMV-712 is connected to a 40a relay that opens / closes the AC charger's output based on specified voltage. This is working fine, but there are substantial efficiency losses with this method.
- Are 48v DC-DC chargers even a thing? The Victron Orion series seems to be available only in 12v / 24v.
- I know a 48v SCC can't work on its own, but I've seen some inexpensive adjustable DC-DC step up converters that take in up to 60v / 15a and output up to 80v / 10a (some models even higher). Could the output of one of these be connected to the PV input of the portable's MPPT SCC to give it 80v so it can charge the portable? It probably wouldn't charge as quickly, but it would be way more efficient than double AC conversion. Here is an example device: https://www.amazon.com/Booster-Converter-Constant-Current-Voltage/dp/B07KDQ2VY2/
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