Voltage converter plus battery charger?

[Sterling9250]

I am looking to get a device that can take 48 volts from a battery and convert it to 230 VAC. However, I am also wanting the device to be able to take 230 VAC and charge the 48 volt battery, sometimes performing both functions. What exactly would this be if it exists? No solar is involved.

If it sounds weird let me explain. I have spare batteries sitting around. I can charge the batteries at night at 50% of the electrical cost. I can then draw from the batteries during the day where electrical costs are much higher. I can put a timer on the charger to charge only during the night.

 

[kommando]

Bidirectional battery inverter, Google it for examples.

 

[Sennen]

Solark 15k and eg4 18k do this, don't they?

 

[timselectric]

I am looking to get a device that can take 48 volts from a battery and convert it to 230 VAC. However, I am also wanting the device to be able to take 230 VAC and charge the 48 volt battery, sometimes performing both functions. What exactly would this be if it exists? No solar is involved.

If it sounds weird let me explain. I have spare batteries sitting around. I can charge the batteries at night at 50% of the electrical cost. I can then draw from the batteries during the day where electrical costs are much higher. I can put a timer on the charger to charge only during the night.

Cheapest option is a Growatt SPF-5000-ES.
It will do what you want automatically, according to the times that you set.

 

[timselectric]

Solark 15k and eg4 18k do this, don't they?

No
The Sol-Ark 15K is split-phase 120v/240V.
And there's no such thing as an EG4 18k.

 

[sunshine_eggo]

I am looking to get a device that can take 48 volts from a battery and convert it to 230 VAC. However, I am also wanting the device to be able to take 230 VAC and charge the 48 volt battery, sometimes performing both functions. What exactly would this be if it exists? No solar is involved.

You are describing an inverter/charger. The portion in bold is not possible as the same circuitry is used, and it can only happen one at a time.

When inverting 48VDC to 230VAC, it's purely drawing from batteries.

When charging from grid, it can't invert, so it passes through the grid power to its output while charging the batteries. Once AC to DC charging stops, it resumes inverting DC to AC.

If it sounds weird let me explain. I have spare batteries sitting around. I can charge the batteries at night at 50% of the electrical cost. I can then draw from the batteries during the day where electrical costs are much higher. I can put a timer on the charger to charge only during the night.

It doesn't sound weird at all. Your desired use is very common.

Cheapest option is a Growatt SPF-5000-ES.
It will do what you want automatically, according to the times that you set.

Listen to this guy. He knows that unit well.

 

[Sennen]

And there's no such thing as an EG4 18k.

You keep saying this... would you prefer I call it the 12K to be 'accurate'? https://eg4electronics.com/categories/inverters/eg4-18kpv-12lv-all-in-one-hybrid-inverter

 

[sunshine_eggo]

You keep saying this... would you prefer I call it the 12K to be 'accurate'? https://eg4electronics.com/categories/inverters/eg4-18kpv-12lv-all-in-one-hybrid-inverter

You forgot the PV!

 

[timselectric]

You keep saying this... would you prefer I call it the 12K to be 'accurate'? https://eg4electronics.com/categories/inverters/eg4-18kpv-12lv-all-in-one-hybrid-inverter

I would have preferred that they named it correctly.
But since they gave it a click bait name. You have to be careful discussing it.
It's name is accurate. (Technically)
it does have an 18kpv charger.
Your shortening it insinuates that it's something that it's not.

 

[OffGridForGood]

Cheapest option is a Growatt SPF-5000-ES.
It will do what you want automatically, according to the times that you set.

Listen to this guy. He knows that unit well.

+1

You are describing an inverter/charger. The portion in bold is not possible as the same circuitry is used, and it can only happen one at a time.

When inverting 48VDC to 230VAC, it's purely drawing from batteries.

When charging from grid, it can't invert, so it passes through the grid power to its output while charging the batteries. Once AC to DC charging stops, it resumes inverting DC to AC.

Option, to allow charging at the same time as inverting: Growatt plus Charger.
instead of using the Growatt AC-input which as @sunshine_eggo noted will mean it can either charge or invert, but not both at the same time. Use a dedicated 230AC to 48v DC charger on a timer instead - to suit the low cost power time.

 

[timselectric]

Option, to allow charging at the same time as inverting: Growatt plus Charger.
instead of using the Growatt AC-input which as @sunshine_eggo noted will mean it can either charge or invert, but not both at the same time. Use a dedicated 230AC to 48v DC charger on a timer instead - to suit the low cost power time.

That would work. But it would require a larger battery bank. In order to cover the loads at all times that the charger is off.
By using the AIO to do everything. When the battery gets low it passes the grid through.
This way you are not completely relying on the battery capacity. But you can use it to its full advantage. Even if you start with a small battery.