Charger - Inverter combo in one box

[Dave911]

Anyway, I am looking for a device to maintain (charge without damage) a 48 volt bank of LIFEPO4 batteries and also invert the power to 120 VAC when the AC is no longer available. This is pretty much the function of a UPS. But I don't need UPS switching speed. Why can't I find such a device that doesn't cost $800+ for 2000 watts? I want to be able to charge at 2000 watts and discharge at 2000 watts. I can find them with a 230 volt input and output (most of the world ignores 120 VAC) but everything at 120 VAC is expensive.

Before you say, buy a Chargeverter from EG4; I don't believe Chargeverters actually turn off the output in anyway. So as long as I have the Chargeverter connected and powered, I am applying volts to the battery bank. This is supposed to be bad for LIFEPO4 batteries, although I am not exactly sure why if the output voltage is not at the fully charged level - ie in the hockey stick part of the charging curve.

There will not always be a load on the inverter. It will be driving a small air conditioner which will switch on and off depending on temp.

This system needs to run unattended. So I can't babysit it. I'll be two hours away at least.

Any ideas? I thought about using a Solar AIO inverter but at the low price end the 120 VAC input and output is a problem with a 48 volt bank. I don't want to add an autotransformer so I can drive a 120 VAC load from a 230 VAC output inverter.

I don't have 230 volts available as an input, only 120 VAC.

I could go to a 24 volt battery bank if required. But even at lower voltages I'm not seeing what I want for a reasonable price.

Any ideas?

 

[wildbillpdx]

Maybe this is more inline with your needs:

EG4 3kW Off-Grid Inverter | 3000EHV-48 | 3000W Output | 5000W PV Input | 500 VOC Input

Power your off-grid setup with the EG4 3kW Off-Grid Inverter (Model 3000EHV-48), ensuring reliable energy conversion and performance for residential and small commercial applications. Available now at Signature Solar.

signaturesolar.com

 

[Brucey]

Pretty sure the chargeverter operates as a battery charger and isn't just a dumb power supply that feeds your lfp until it lets the magic juice out.

 

[Mattb4]

post deleted

 

[Dave911]

That might do it but its not cheap.
I don't really need the PV inputs.
Who makes this inverter for EG4? Is this a Voltronic unit or SRNE or ?
I don't think I can buy this from Signature Solar or EG4 after watching them berate a customer on this forum, yes, in public.
Looks like max AC charging is 40 amps reading from a search in this forum.
Thanks

 

[Dave911]

Pretty sure the chargeverter operates as a battery charger and isn't just a dumb power supply that feeds your lfp until it lets the magic juice out.

Yeah, a logical person would think so. But if you do a search on the Chargeverter you will find that it is two Telecom "Rectifiers" in a box. There is a teardown video on youtube.

 

[timselectric]

Pretty sure the chargeverter operates as a battery charger and isn't just a dumb power supply that feeds your lfp until it lets the magic juice out.

It's just two power supplies in a box. With a control/display.
It's as simple as it gets. Which is what makes it so great.

 

[Dave911]

It's just two power supplies in a box. With a control/display.
It's as simple as it gets. Which is what makes it so great.

Yes, for its purpose it might be fine. But its not obvious thats its not a smart charger.

 

[zanydroid]

Yes, for its purpose it might be fine. But it’s not obvious thats it’s not a smart charger.

You’re reading too much into the name. Rectifier in Telecom can mean charger.

If the name really meant something, it would be a couple diodes and nothing else. Clearly not the case.

If it was that bad as you say, there wouldn’t be so many devotees of the chargeverter.

 

[timselectric]

Yes, for its purpose it might be fine. But its not obvious thats its not a smart charger.

I have personally opened both of mine.
And there are plenty of tear down videos on YouTube.

 

[marionw]

The EG4 ChargeInverter does have adjustable Max Output Voltage and Max Output Current settings.

With the right settings it would float the batteries and power the load. The batteries would take over when AC failed to the ChargeInverter. When AC came back the ChargeInverter would recharge the batteries using up to the max voltage and max current per the settings.

 

[chrisgraham]

post deleted

 

[ksmithaz1]

Pretty sure the chargeverter operates as a battery charger and isn't just a dumb power supply that feeds your lfp until it lets the magic juice out.

Pretty sure the chargeverter is just a smart power supply/dumb charger that will happily feed up to the selected voltage to whatever load you connect it to at up to whatever current level you specified. It's not a BMS, it's just a power supply,

The rate at which a naked battery charges is based on the internal resistance and the delta between the current pressure in the cells and the pressure applied (volts). The CV will reduce that delta to limit the charge rate to whatever you set. If you set the max voltage up beyond what the battery will handle it will happily attempt to provide power it until your target battery overcharges, which could indeed destroy it.

The 'float' voltage of a battery is the maximum voltage you should apply to keep the battery at a fully charged state without overcharging it. As the delta narrows the charge rate goes down because of the battery, it's internal resistance goes up, not the charger, thus the charge rate will diminish as the internal pressure approaches the float voltage. A BMS can signal to a "smart" charger that it can bring the voltage above the float voltage to increase the delta / allow faster charging / cell balancing / whatever at the top end of the charge cycle, and then request a drop back to float voltage when it detects all the cells are full.

An old fashion 'dumb' automotive battery charger simply applies it's peak voltage all the time, with a thermal/current cutoff that cycles for shorter and shorter periods as the battery charges, and the pressure delta narrows reducing the current flow below the trigger threshold for the thermal breaker. The newer 'smarter' ones have a simple detector that flips to a 'trickle' charge, the old ones would happily cook your battery. When it detects the delta reaches a certain level, it lowers the voltage to a 'float' voltage. A trickle charger is generally even dumber. It's usually just a transformer and/or a discrete IC that provides a float voltage which will simply drop down the voltage until its not overloaded, often leveraging it's own internal resistance.

 

[DIYrich]

Renogy 48V 3500W Solar Inverter Charger

Renogy's 3500W 48V Solar Inverter Charger combines solar charging, AC/generator battery charging, and battery inverting into one convenient solution. Free shipping

www.renogy.com

 

[DIYrich]

Before you say, buy a Chargeverter from EG4; I don't believe Chargeverters actually turn off the output in anyway. So as long as I have the Chargeverter connected and powered, I am applying volts to the battery bank. This is supposed to be bad for LIFEPO4 batteries, although I am not exactly sure why if the output voltage is not at the fully charged level - ie in the hockey stick part of the charging curve.

Any ideas?

if you are not cycling much, consider lead acid battery. I belive floating is ok for them.

If lifepo4, floating at 53.5v may work. That is close to resting voltage (batteries floating each other).

 

[Brucey]

Pretty sure the chargeverter is just a smart power supply/dumb charger that will happily feed up to the selected voltage to whatever load you connect it to at up to whatever current level you specified. It's not a BMS, it's just a power supply,

The rate at which a naked battery charges is based on the internal resistance and the delta between the current pressure in the cells and the pressure applied (volts). The CV will reduce that delta to limit the charge rate to whatever you set. If you set the max voltage up beyond what the battery will handle it will happily attempt to provide power it until your target battery overcharges, which could indeed destroy it.

The 'float' voltage of a battery is the maximum voltage you should apply to keep the battery at a fully charged state without overcharging it. As the delta narrows the charge rate goes down because of the battery, it's internal resistance goes up, not the charger, thus the charge rate will diminish as the internal pressure approaches the float voltage. A BMS can signal to a "smart" charger that it can bring the voltage above the float voltage to increase the delta / allow faster charging / cell balancing / whatever at the top end of the charge cycle, and then request a drop back to float voltage when it detects all the cells are full.

An old fashion 'dumb' automotive battery charger simply applies it's peak voltage all the time, with a thermal/current cutoff that cycles for shorter and shorter periods as the battery charges, and the pressure delta narrows reducing the current flow below the trigger threshold for the thermal breaker. The newer 'smarter' ones have a simple detector that flips to a 'trickle' charge, the old ones would happily cook your battery. When it detects the delta reaches a certain level, it lowers the voltage to a 'float' voltage. A trickle charger is generally even dumber. It's usually just a transformer and/or a discrete IC that provides a float voltage which will simply drop down the voltage until its not overloaded, often leveraging it's own internal resistance.

The chargeverter is the charger components of one of the eg4 all in ones. It will float a bank, it doesn't need any special supervision/manual shutoff like a power supply would.

EG4 Chargeverter | 48v 100A Battery Charger | 5120W Output | 240/120V Input

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

 

[Dave911]

The chargeverter is the charger components of one of the eg4 all in ones.

I've read that before but I don't think that is the case.
I doubt that a significant inverter manufacturer would incorporate a ready made Telecom 48 volt flatpack rectifier in a mass produced product.
Perhaps they did in the past.

SS and EG4 don't make anything that I am aware of. Perhaps they make/assemble the Chargeverter?
They are mostly a distributor of equipment made elsewhere. Nothing wrong with that. I deal with distributors all of the time.

Here is the teardown video.

I'm not in the Telecom industry but apparently these flatpack rectifiers are very common to charge and maintain 48 volt power banks on Cell towers, Telecom stations, etc.

If you go to Ebay and do a search for "Flatpack 48". You will see a lot of them for sale.

If you want to roll your own chargeverter there is a lot of folks who have done that already.
There is Arduino/PC code out there to talk to these devices via CANbus. No need to reinvent the wheel.
At least one of these flatpack devices can be programed via a CANbus interface and set to a certain voltage and current limit.
There are also provisions to communicate between multiple flatpacks so they can operate in tandem. Need more amps, add more flatpacks.

 

[gotbeans]

That might do it but its not cheap.
I don't really need the PV inputs.
Who makes this inverter for EG4? Is this a Voltronic unit or SRNE or ?
I don't think I can buy this from Signature Solar or EG4 after watching them berate a customer on this forum, yes, in public.
Looks like max AC charging is 40 amps reading from a search in this forum.
Thanks

I could be wrong but I've seen tons of people say Voltronic.
If you look up that inverter and watch will's youtube video he might say who

They discuss it here but they're unsure

New EG4 3kW Off Grid All-In-One Inverter - Anyone with experience??

Looking to throw together a little system for a vacation home of ours purely as a backup to the grid. Called Signature Solar yesterday to order a couple Growatt 3000's and EG4 batteries as well as to ask about their Garage Sale items. They happen to have both of those items available in the...

diysolarforum.com

 

[gotbeans]

The chargeverter is the charger components of one of the eg4 all in ones. It will float a bank, it doesn't need any special supervision/manual shutoff like a power supply would.

EG4 Chargeverter | 48v 100A Battery Charger | 5120W Output | 240/120V Input

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

I don't think anything uses these components internally. The flatpack 48volt "re-use" is only in these chargeverters as far as I've seen

Maybe this is more inline with your needs:

EG4 3kW Off-Grid Inverter | 3000EHV-48 | 3000W Output | 5000W PV Input | 500 VOC Input

Power your off-grid setup with the EG4 3kW Off-Grid Inverter (Model 3000EHV-48), ensuring reliable energy conversion and performance for residential and small commercial applications. Available now at Signature Solar.

signaturesolar.com

This is what I'd go with, they're less than $800 as OP asked for, and even more watts than he asked for.
The "chargeverters" aren't inverters, they're just chargers, aren't they? They aren't converting anything to AC, their name is wrong/bad.
The eg4 3000 can do this though, and act as a "large" battery backup / UPS system
Just ignore the PV input