GivEnergy inverter & battery, and separate 3rd party inverter and battery

I currently have a GivEnergy Hybrid 5kW Gen 1 and a 9.5 kWh battery, installed all by an authorised engineer and it works well. However, as we know the batteries can only charge at 2.6 kW with this inverter, and so if I ever exceed this the power is exported.

I wanted to find an inverter from a 3rd party, which I could use to absorb this excess energy not being used to charge the GivEnergy battery, to charge another set of 3rd party batteries, continuing to send any excess after they're charged to the grid.

I saw some suggestions a while ago to use a GoodWe GW2500-BP Charge Controller which would sit in between the GivEnergy inverter and the solar panels, however the GoodWe inverter doesn't seem to be manufactured any more, so would present a problem if it ever broke down, finding a like-for-like replacement would probably be difficult.

I could probably do this kind of install myself, since I could shut off both the GivEnergy inverter and PV arrays using the isolators.

The manual for the GoodWe inverter seems to be pretty much what I want:

A GoodWe BP series hybrid converter can upgrade a generic single phase or Goodwe SDT three phase grid-tied inverter into an energy-storage system.
During daytime, PV panels generate electricity which can be firstly supplied to the local loads, then the excess energy will be used to charge the batteries via the hybrid converter. During the night, the battery will discharge. The electricity will be provided to the local loads with the hybrid converter and the PV grid-tied inverter. The hybrid system improves the self-consumption ratio greatly

Is anyone aware of a similar replacement?

NotoriousPyro Shout out to @hoggy as he's done this and may be able to advise on what might be suitable.

Thanks @Tim,

I found GW6000-SBP-20 (SBP G2) which appears to be very close to the same, but instead of sitting between the inverter and panels, it uses two CT clamps and an AC output.

I don't think they produce a like-for-like replacement so unless there's another brand... I think this diagram in the manual most accurately represents what needs to be configured but it would be good to have input from @hoggy if he has any better ideas:

NotoriousPyro Checkout @hoggy's web site. It has a System Topology diagram of his configuration near the bottom.

Tim Yeah, as I say though that inverter is no longer produced. So unless there's a supplier still operating somewhere with some stock or a suitable replacement...

Also, if the Goodwe inverter is placed on a PV string, it has potential to export to the grid I would have thought, no? Exporting to Octopus at night with PV and they may well decide I've violated their T&Cs as I believe it says export from batteries is disallowed.

I think I have to go about this with a newer inverter, the above one I believe checks the power consumption between the grid-tied inverter (GivEnergy) and the utility, so that it does not export.

NotoriousPyro / @Tim right so to clarify a few things:
The Goodwe 2500BP is indeed no longer made. They were never that popular over here and to date (from 2021) I've only seen 3 for sale - and I bought one of them!
Reliability wise there's a lot less going on internally than a "normal" inverter as it is all purely DC. Therefore I think they will last a fair time but it is a bit of an unknown.
Essentially it's a giant controllable Buck - Boost converter where it takes 40V-60V up to 120-600V the same as your panels are running at and vice versa.

How they work - they are purely DC coupled and as such don't have the ability to export at all, so that part means no messing with DNO or adjustments as there is the Givenergy Inverter still that provides a destination for it to discharge into.
(You can if you are willing to eat the losses, "see-saw" power from the Goodwe batteries into the hybrid batteries by forcing the Givenergy to AC grid charge (the Goodwe thinks it's fulfilling a house load) and then discharge the GE battery after but it's a lot of steps for little gain.
They do monitor export & import as that is how it "knows" the house doesn't need the extra panel power & when it needs to discharge.
It works at night fine (it just fixes itself at _300V and offers up 2500W to whichever string your plugging it into.
It prioritises load (Givenergy) first so it will only start stealing power once both the house & the Givenergy demands are exceeded and you start exporting.

HOWEVER the biggest problem as such is that you can't charge the batteries AT ALL from AC, so there is no overnight cheap rate boost available. So in Winter when you probably need it most it generally is just sat there being flat.
You could i guess rig up a separate AC charger to the batteries but honestly just go AC coupled by the time you've messed around doing that.
The GW6000-SBP-20 is AC coupled which is the more modern approach, so your export gets shunted into batteries AFTER the Givenergy Hybrid has converted it to AC. It's a bit more lossy but you benefit from being able to fill them on cheap overnight power. I'm unsure why you'd choose Goodwe for this task when Givenergy have their own version called an AC3 or the new AIO but there's a fair few others that can do it.

If your totally adamant on following my setup, there is also the Growatt SP2000 which does the same as the Goodwe however be warned:
I've not tried it (but oh so tempted just for curiosity)
It's equally ancient / no longer made.
I THINK it only works with their battery (the weird Darfon one - which has a tendency to roast it's BMS when it can't balance cells)
as per above - dubious / unhappy battery systems end up on eBay VERY regularly so you may get burned with a battery that is a doorstop with no way to make any other battery work with it.

I did suggest to GE that they could make their own version of the Goodwe and loop it back to the GE battery to make Gen1 into Gen 2-3 (you could technically push charge rates to 5kW if you have more than 1 battery - the BMS is the limiter really) however that was before Gen2-3 came along so it kind of pointless now you can just slot one of those in the Gen 1s place.

I have Gen 1 3.6kW hybrid and 9.5kWh battery from Giv Energy with 3.6Kw solar panels, all works great, then I added a Goodwe EM Series hybrid inverter and another 5 off pylontech 2000C batteries with 3Kw Solar panels.. The GivEnergy feeds the house and exports to grid as normal, and the Goodwe is connected with CT clamp to one of my ring mains. This set up allows me to solar charge all batteries from their respective panels, charge overnight at cheap rate both sets of batteries in parallel. Using GivTCP I can control when each setup charges discharges, power levels etc, therefore I can take 2.6Kw from GivEnergy and 2.6Kw from pylontech at the same time ie 5.2kW of power if required. I can also move the charge between the batteries if needed, ie one system gets more sunshine than the other then i can force export on one and force import on the other. This setup works well and I'm really happy with it. My aim is to use the Goodwe setup to feed power to the ring mains feeding the electric heating, and Givenergy for lights, cooking etc. Trying to get off of gas completely so this winter will prove if this setup works allowing me to dump gas. :-) . The plan next is to add the VTL from the car to feed into the house so I can also make use of the car's battery for heating. charge car at night in parallel with batteries and then use whenever throughout the day....therefore battery storage is circa 9.5 (GivEnergy) + 12 (Goodwe pylontech)+ 64 (MG4 car).....85.5kWh should be enough !!!!!

Annaka Can you give more detail how this is controlled?

I was hoping for something automated, e.g. the 2nd inverter would have a setting to only charge when there was export (as in the GivEnergy battery was already full or there was excess above 2.5 kW to charge the GivEnergy battery).

I think as hoggy has suggested with the GW6000-SBP-20 using the export of converted AC is possibly the set up I want, yes it is a bit more lossy but it is worth the price to pay for full automation, unless yours avoids that somehow Annaka? However, I will definitely look into the EM series.

Hi, with HomeAssistant , GivTCP and also the GoodWE integration (for homeassistant) you really can do whatever you like, I use Node Red for all automations it's so much easier (in my mind) than trying to code in yaml. Are you using Homeassistant ?? if not it would really pay you to take the plunge and get familiar with it, also with Node Red (addon to Homeassistant). By getting familiar with this software will really open your options up. I have for instance set some automations to either supply the mains feeding into my ringmains from either the goodwe or givenergy batteries. Givenergy is the default but if I force export from Goodwe it discharges that battery rather than the Givenergy battery. So i measured the current being drawn from various electrical items, like towel radiators, hot water tank etc and then I can tell Goodwe to supply that amount of current. Other automations I have set also determine the level of charge I put into the battery overnight based upon Solcast predictions, I then adjust this value in accordance with my setup ( I have quite a few trees close by) which allows me to really tailor the charge overnight for my Solar setup. I find all the other predictions are really based upon a clear sky which doesn't reflect reality for me. The possibilities are endless.

Get Homeassistant and have fun, beats watching tv when you can watch your system working just how you want it to. Also another HA integration to use is Graphana, this allows you to produce super quality graphs to show anything you want about your system. You wont look back :-)