jdege
New Member
- Joined
- Dec 16, 2020
- Messages
- 138
I'm building, in piecemeal fashion, the electrical systems for a liveaboard sailboat.
What I have currently are two 48V, 100Ah LiFePO4 batteries, each powering a separate electric motor, and each with its own 120VAC->48VDC, 22A charger.
And temporarily, I'm using a Bluetti AC200MAX for everything else. I have one of its DC outputs wired into the boat's DC distribution, powering bilge pump, internal lights, etc. The boat doesn't currently have AC distribution, when I need AC onboard (mostly for cordless power tool charging) I plug directly into the Bluetti.
The boat had a non-functional propane stove that I've removed. I intend to replace it with a combo air-fryer/microwave and induction cooktop. For that I will need AC distribution. I may end up wiring that to the Bluetti, temporarily, but eventually I'll want a LiFePO4 house bank and an inverter.
So figure I'll be adding a 12V, 200 Ah LiFePO4 house bank, with a 120VAC->12VDC, 25A charger, and an 2000W 120VAC inverter. That will give me three separate banks.
I like the redundancy of having separate banks, but only if I can use them interchangeably.
In my ideal world I'd be able to charge each from any other, run DC distribution from any one of the three, and run an AC inverter from any of the three. But how to switch it?
I'm thinking a three position switch for each charger, 1 to charge from shore power, 2 from the inverter output, and 3 off. The chargers only draw 7-8A AC. I can run all three from a 120V 30A shore power pedestal with no issues. Or any two from a 2000W inverter. (And charging a battery from an inverter that's powered by the same battery is just stupid.) 120V switches in the 4-7A range are ubiquitous.
But running an inverter from a 48V bank is a different problem.
As for powering DC distribution from 48V, that's simple enough, except for the inverter.There are 48V->12V DC-DC converters, but to power a 2000W inverter I'd need 170A at 12V, which is a lot. Are there converters available in that range?
Or would a lower capacity converter make more sense, with a separate 48V inverter?
Or am I letting my sense of "it would really be nice if, just in case" run away with me?
What I have currently are two 48V, 100Ah LiFePO4 batteries, each powering a separate electric motor, and each with its own 120VAC->48VDC, 22A charger.
And temporarily, I'm using a Bluetti AC200MAX for everything else. I have one of its DC outputs wired into the boat's DC distribution, powering bilge pump, internal lights, etc. The boat doesn't currently have AC distribution, when I need AC onboard (mostly for cordless power tool charging) I plug directly into the Bluetti.
The boat had a non-functional propane stove that I've removed. I intend to replace it with a combo air-fryer/microwave and induction cooktop. For that I will need AC distribution. I may end up wiring that to the Bluetti, temporarily, but eventually I'll want a LiFePO4 house bank and an inverter.
So figure I'll be adding a 12V, 200 Ah LiFePO4 house bank, with a 120VAC->12VDC, 25A charger, and an 2000W 120VAC inverter. That will give me three separate banks.
I like the redundancy of having separate banks, but only if I can use them interchangeably.
In my ideal world I'd be able to charge each from any other, run DC distribution from any one of the three, and run an AC inverter from any of the three. But how to switch it?
I'm thinking a three position switch for each charger, 1 to charge from shore power, 2 from the inverter output, and 3 off. The chargers only draw 7-8A AC. I can run all three from a 120V 30A shore power pedestal with no issues. Or any two from a 2000W inverter. (And charging a battery from an inverter that's powered by the same battery is just stupid.) 120V switches in the 4-7A range are ubiquitous.
But running an inverter from a 48V bank is a different problem.
As for powering DC distribution from 48V, that's simple enough, except for the inverter.There are 48V->12V DC-DC converters, but to power a 2000W inverter I'd need 170A at 12V, which is a lot. Are there converters available in that range?
Or would a lower capacity converter make more sense, with a separate 48V inverter?
Or am I letting my sense of "it would really be nice if, just in case" run away with me?
