Armageddon backup system- MPP or Growatt

[garbec]

I'm looking to power critical loads in my house (fridge & freezer & furnace) if grid goes down for long periods in bad times. I like the idea of getting a MPP or Growatt all in one. The system would be tested occasionally then turned off when not needed. Leaning toward the used 250W panels with snail trails. I was all excited about the bigbattery.com 24V battery for $699, but see it is now $1699 (but new). Questions:
* 24V or 48V? I like that the Growatt spec allows 4500w of solar on the 48V model vs 2000W for the 24v model. I could use more (3S3P) of the 250 watt panels.
* Growatt vs MPP?
* Other good battery options vs the $1699 bigbattery.com (24V & 48V)? Seems like $1699 might be worth it.
* No warnings about the used 250W snail trail panels?

 

[garbec]

Another question: Can the AC charge current be set to lower, like 15 Amp, if you are plugging it into a standard outlet?

 

[geocline]

ha! having the exact same question!! Thanks for asking so clearly!

 

[Abbott]

I'm looking to power critical loads in my house (fridge & freezer & furnace) if grid goes down for long periods in bad times. I like the idea of getting a MPP or Growatt all in one. The system would be tested occasionally then turned off when not needed. Leaning toward the used 250W panels with snail trails. I was all excited about the bigbattery.com 24V battery for $699, but see it is now $1699 (but new). Questions:
* 24V or 48V? I like that the Growatt spec allows 4500w of solar on the 48V model vs 2000W for the 24v model. I could use more (3S3P) of the 250 watt panels.
* Growatt vs MPP?
* Other good battery options vs the $1699 bigbattery.com (24V & 48V)? Seems like $1699 might be worth it.
* No warnings about the used 250W snail trail panels?

i just got 16 santan "snail trail" panels 250W originally Trina product. i bid $30 per panel and they countered $36. 15 of 16 tested 37.5-37.7V (perfect) and one is 35V(sub-par). I am only planning 8 panels (2000W hookup for now). I am leaning Growatt 3000, but based on Wills info, i think either that or MPP are equally good. I'm going 48V and got 4 LiFePo4 used batteries from Battery hook up for $99 each. I only need this for backup offgrid if my on grid system goes down.

 

[guyroch]

Another question: Can the AC charge current be set to lower, like 15 Amp, if you are plugging it into a standard outlet?

Yes for the Growatt. You can set down to 1 amp AC charge current it you want.

 

[jasonhc73]

The MPPSolar LV6548 can do 2 amps times how many inverters you have.
The MPPSolar LV5048 can do 10 amps times how many inverters you have.