looking for a 240v - 24volt Variable Amperage battery charger

Hi,

I have no idea if these exists, but I'm looking for a 240v - 24volt Variable Amperage battery charger,

some background,

I have a grid tied 5Kw System ( using 10 micro inverters ), and as of this year my export returned has dropped from 0.28c a KWh to just over 0.08 cents, ( the power company has a monopoly where I live )

so I've been looking into adding some more solar to run a second system to charge 18650 power wall, and use the output to run 'some circuits' in my house, but I'm wanting a way to use some of my 'export' to charge these battery as well ( during the day when I'm at work )

so depending on how many Watts are been exported have the charger start charging at a low amperage, and as my grid tired system exports more, have the charger ramp up its amperage, so my export is close to zero ( until my batteries are full )
I have a EmonTX Sheild ( https://wiki.openenergymonitor.org/index.php/EmonTx_Arduino_Shield ) that I will use to see whats been exported, and would like to usethis to talk to the 'charger' to ramp up the amperage,

so does anyone know if something like this exists, or a diy project to build one ?

thanks in advanced,

Nigel

Well, that is what an hybrid inverter with batteries does in grid tie mode, if you configure it, at least my MPP Solar does it.

It has different modes to setup to charge batteries or feed the grid, I have in that order:

1-House comsumption
2- Battery Charge
3- Grid Feed





Regards

jesusangel said:

Well, that is what an hybrid inverter with batteries does in grid tie mode, if you configure it, at least my MPP Solar does it.

It has different modes to setup to charge batteries or feed the grid, I have in that order:

1-House comsumption
2- Battery Charge
3- Grid Feed





Regards

Click to expand...

I forgot to mention ( which I have updated now) that my 5Kw system is using micro inverters, so its not as easy just to replace the 1 inverter,

noddle said:

jesusangel said:

Well, that is what an hybrid inverter with batteries does in grid tie mode, if you configure it, at least my MPP Solar does it.

It has different modes to setup to charge batteries or feed the grid, I have in that order:

1-House comsumption
2- Battery Charge
3- Grid Feed





Regards

Click to expand...

I forgot to mention ( which I have updated now) that my 5Kw system is using micro inverters, so its not as easy just to replace the 1 inverter,

Click to expand...

In your case yes, it is a bit more difficult, I do not know any charger that can vary the charging power depending on an external energy meter.

Eltek chargers with canbus works.

[/quote]

I forgot to mention ( which I have updated now) that my 5Kw system is using micro inverters, so its not as easy just to replace the 1 inverter,
[/quote]

In your case yes, it is a bit more difficult, I do not know any charger that can vary the charging power depending on an external energy meter.
[/quote]

I also have micro inverters and I'm looking at fitting the SOFAR MASS ENERGY ME300SP. It's an AC coupled charger/inverter. Works like an hybrid inverter but uses AC not DC.

It's good for various battery types and Voltage, amperage limits can be user set.

http://www.sofarsolar.com/product-detail/323/ME-3000SP

Only downside for me is, its a max load of 3kW, I would have liked to been able to supply maybe 5kW to 7kW. At the moment though it's the one I'll be going with.

A simple, but not cheap,method of adding storage to any existing grid tied installation (whilst leaving the existing system in place and unouched) is Victrons ESS using one of theircombined inverter/chargers such as the MPII 5000

Surplus PV will be diverted to battery -for as long as you have battery capacity,the system will keep your input and export at zero.

https://www.victronenergy.com/live/ess:design-installation-manual