I linked it to my main unit, charged it. Everything worked as it should. The power connection cable is very sturdy. Well-made as well.

Very well packaged and delivery was prompt. The battery itself arrived 84% charged and synced well with my F3800. Wait for the sale price here.

I have the F3800 with 1 extra battery and the power panel. I also have some solar panels but haven't used them yet. The negative reviews I have seen seem unwarranted. One complained about their slow tech support and the other complained that the battery was useless without the F3800 (duh). Tech support is good and extremely helpful, they are just in a different time zone. I have the F3800, a couple of C1000's and a C800 plus other smaller units. All for specific tasks and they do those tasks very well and I am happy. When I'm not worried about power outages, I use them to store energy from the grid and use it during high peak (and high price) times. That's a price difference of 28.9 cents per kWh in the summer where I live. Use them all with programmable smart outlets to determine timing of getting power from the grid and I'm happy. I will be getting solar panels for the house and then I'll be even more happy.

Solid BThey have a solid build and nice capacity. You need to make them useable and chargeable without the base though. It would be nice to be able to use and charge them separately when you're not needing the full power of the 2 together.

High quality, sits nicely on top of my F3800 and adds another 3.8kw of power!