The refund was for 100% of the purchase price minus the cost of shipping. Their refund/return policy is extremely clear, linked here:
https://signaturesolar.com/shipping-returns/
They never actually detailed how they came up with the figures they used.
My purchase price was $1,499 + $182.12 (shipping) = $1,688.12 total.
They chose to NOT refund me 100% of the purchase price because they couldn't reproduce the issue. So let's assume a 100% refund would have been $1,499. What I actually got was $939.05. That means the return shipping cost was $749.07. So to buy the battery cost $182.12 in shipping, but to return it, it cost $749.07 in shipping? Hunh?
This is part of the customer service issue. They never detailed how they came up with the numbers they were working with.
Oh, and the refund wasn't for 100% of the purchase price minus shipping. They also take 30% for restocking fees, but only in the event that they determined the battery was fine and I was at fault. That was my biggest complaint.
They can only work with the information you provided - and they did in fact at one point try to have you use a different vacuum for testing (to which you responded that you knew it wasn't the vacuum causing the issues, and that you knew it was the battery not being able to handle a relatively small spike in power demands).
And I didn't want to go out and buy another vacuum just to prove that the battery was failing when running the original vacuum.
In my opinion, you had great customer service, and it is only the outcome you are upset with that has swayed your opinion. I don't personally believe that not getting your desired outcome is the same as receiving poor customer service.
Does the battery work like it should? Maybe. Did it work for me? No.
If I had the time and tools (and was in the right location), I'd love to perform endless tests on the whole system to see exactly what happens in each part of it to determine where the fault is. If, of course, I wanted to uninstall all of the components, bench test them, and tinker with it for days on end. Then I could say, without fail, that component 'X' was the problem or caused the cascade of events to happen the way they do.
What I think happened was that the LV6548 made a huge power demand on the battery when the vacuum started up. That demand was well beyond the power requirements of the vacuum. Because the MPP LV6548 is a high frequency inverter, it just doesn't have the ability to gracefully handle surge loads without putting huge demands on the battery. That's why my old setup with a low frequency Outback inverter plus an Overkill Solar BMS on a DIY LiFePO4 bank worked so well. I'm not sure what the short-circuit rating of that Overkill BMS is, probably similar to the EG4, but because the Outback inverter can handle the surge demands so much better than the MPP, the whole system just works better.
Here's what I'd really like to see:
- Detailed breakdown of how customer service came up with the refund figures that they did. They never did provide that.
- Some kind of description or warning on the EG4 battery page detailing how modern, high-wattage, high-frequency inverters can cause HUGE inrush spikes that are well beyond the limits of a single EG4 battery.
I was working on the assumption that this new inverter would work in a way that was similar to the low-frequency inverters I was accustomed to. Sure, it had a max output of 6,000 watts, but I wasn't going to be going anywhere near that, so the 4,000+ watts that the EG4 battery could output would be more than enough for my needs for the couple of months I was going to use it in that configuration. Yes, the LV 6548 manual said it should be hooked up to 200ah of batteries, but it didn't say
why. Apparently it's because of the huge inrush demands of that inverter. I just figured it was for the sustained demands of running 6,000 watts, which I wasn't trying to do.
If, for example, you were running the inverter with a 4,000 load and
then turned on the vacuum, you better have a whole rack of batteries to distribute that load over!
I wish I could throw specific high-amperage loads at the EG4 battery to see how it handles spikes. If the battery is only putting out 3 amps and you throw a 90-amp surge at it, does it die? How about a 150 amp surge for 0.1 seconds? As a consumer, I don't have the equipment (in inclination) to test all of these scenarios. The math just still feels wrong to me -- how could a single appliance overwhelm a server-rack battery? It just didn't (and still doesn't) feel right. And because I can't run those tests myself, I'll never know if the battery I sent back was actually performing like it should or not. And you'll have to forgive me for not trusting the word of Signature Solar's testing team, they certainly didn't believe me that there was an issue.
Sure, I'm learning more about inrush requirements on high-frequency inverters, but I feel like that education came at a very high cost and frustration level.
For what it's worth, I'm going to go back to building my own batteries with raw cells. If a BMS is faulty, then I can ship the BMS back instead of the whole battery system. And I'm going to stick to low-frequency inverters. They just work better than the cheap high-frequency stuff.
One last note on customer service: The modern customer expects more these days. Any major big box store or online retailer will happily and readily accept product back if the customer complains. I don't often need to return things, but in this case, it was a major pain and I was left very upset. So that's my lasting impression of Signature Solar.