Hi everyone,
I work for Portable Sun, a solar distributor in Grand Rapids. Battery compatibility comes up pretty often in this community, so I thought I’d share a few things worth checking before buying an inverter, or before adding a battery to the one you already have.
I’ll use Tigo, Sol-Ark, and Growatt as examples since we carry all three and I know them best. I’m happy to answer questions here for free, whether you’re buying from us or not.
If you told me you were getting solar installed now but wanted to wait a couple of years before buying batteries, the first thing I’d ask is what inverter you’ve got in mind. I’d want its exact model number so I could see which batteries it supports.
Which batteries it’ll take
It’s easy to grab a battery on sale without checking compatibility first. “Battery-ready” is a common advertising term in this industry, and it means an inverter can take a battery. It doesn’t tell you which ones, and depending on the inverter, that list can be a single brand or more than a dozen.
The first thing to check is voltage. You’ll notice that most home batteries are either 48V or high-voltage (a few hundred volts), and an inverter is usually built for one or the other. After that, the battery needs to be on the inverter’s compatibility list.
If it isn’t, the inverter may not be able to read the battery or control its charging properly, and some brands won’t cover the pairing under warranty.
Let’s quickly go through some specific examples:
The Sol-Ark 15K is a 48V inverter with a certified list of batteries from other manufacturers, including the Discover HELIOS 16 kWh battery (we actually sell this together)
Growatt’s MIN 7600TL-XH-US takes high-voltage batteries, either Growatt’s own APX and ARO lines or certain LG models. A battery on the list may still need extra parts.
Growatt’s APX system uses 5 kWh battery modules, but you can’t just buy one module and connect it to the inverter. It needs the matching power module and other equipment.
Tigo’s EI inverter only connects directly to Tigo’s own batteries, including the GO battery.
That limits your DC-coupled battery options, but you can monitor the inverter and battery through the same app, including error codes from both. And if something goes wrong with either one, Tigo supports both pieces of equipment.
You can also add storage through AC coupling, where the battery system has its own inverter.
Running things in an outage
You could have enough battery capacity to keep your refrigerator, well pump, and a few other circuits running all night, only to find out that the pump won't even start. That's because its motor can draw several times its normal running power for a moment when it kicks on, and having plenty of energy stored doesn't mean the system can supply that sudden demand.
I'd check the continuous and surge output ratings of both the battery and the inverter before counting on them for backup. Whichever reaches its limit first is what you're working with.
With Tigo’s GO Battery, for example, three 5 kWh modules give you 7.5 kW of steady output. On a 7.6 kW EI inverter, a fourth module mainly gives you longer runtime, since the inverter’s steady backup output tops out at 7.6 kW anyway.
Cold obviously matters too, since batteries have a minimum operating temperature and put out less power when they’re cold. The GO Battery is rated down to 14°F, which matters on an outside wall in a Michigan winter.
Then there’s the backup equipment
To run the house during an outage, the system needs a transfer switch that disconnects it from the grid.
Tigo and Growatt, for instance, use a separate transfer box (Tigo’s comes in 50A or 200A, and Growatt’s MIN V3 uses the SYN 200-XH-US for whole-home backup), while the Sol-Ark 15K has it built in with 200A grid pass-through.
In Sol-Ark’s case, however, be aware that a 200A grid pass-through doesn’t mean the inverter can supply 200A from the batteries during an outage. On batteries alone, the Sol-Ark 15K is rated for 12 kW, which works out to about 50A at 240V.
In any case (but especially if you DIY), do the math for your own inverter-battery setup so you don’t encounter an unpleasant surprise in a longer outage scenario.
If you wait a few years
The battery you plan to buy now might not be sold by the time you’re ready for it. Your inverter could still be working perfectly, but the manufacturer may have moved on to a different battery generation. Tigo went through this in January 2026, when the GO Battery followed the older EI Battery.
The current EI inverter datasheet lists both as supported options. Sol-Ark’s certified battery list and Growatt’s supported models (and any other company’s) can change too. I’d advise using the current documentation when choosing an inverter, then checking it again when you’re actually ready to buy storage.
Would I buy the battery now?
It depends.
If I knew I wanted backup power and could afford the battery, I’d install it with the panels and get the whole backup setup working at once. But if the battery had to wait, I’d still go ahead with solar, provided I’d chosen an inverter with a documented battery option.
Even if you’re unsure about adding a battery later on, I still wouldn’t let that impact my inverter choice. AC coupling is still an option for many existing grid-tied systems. It’s more equipment, and there can be conversion losses. But replacing a working solar inverter isn’t automatically the better choice.
If you’re looking at a particular inverter, share the model number and what you’d want the battery to do. I’ll hang around in the comments and help where I can. New customers planning a solar installation in the lower 48 states can also get free full-system planning.
