Feeding new solar setup with old for capacity

[eugor8]

Hi all,
I'm to the forum, did some searching on Google and here, but didn't find a thread on exactly what I have a question about.
I am off grid with an outback system with lead acid battery bank:
Outback FLEXpower Two FP2 VFXR3524A-01 7,000 Watts 24 Volts

Outback FLEXpower Two FP2 VFXR3524A-01 7,000 Watts 24 Volts for Off-Grid and Grid-Tie

Note: This item is delayed indefinitely, please contact us for alternative options.

www.solar-electric.com

This system is not big enough for me, so I've bought a pair of MPP solar 6048, along with panels and lithium bank storage.

I want to keep the complete Outback system to use in my workshop, and use the MPP 6048s to power the house and some inductive loads I have. Since the outback system won't be used much anymore, I've become curious if I could wire the AC output of the outback system to the AC input of the mpp 6048 system to increase my total storage for the main system, running off the lead acid bank when the lithium bank gets low. I know I will have some losses in conversion. I'd like to run the generator less iff possible, and if I have a charger/unused battery bank, it just sounds like the best way to use it.
Does anyone see any concerns about running the system like this ? Any advice would be appreciated. Thanks in advance.

 

[viccooper]

How old is your lead acid bank? Might not be worth the trouble to maintain it with all the battery voodoo you have to do with lead acid. Could you setup the Outback to run specific loads rather than the whole house. Also don't you want to move the old solar panels to the new system? What is keeping the Outback system charged up?

 

[eugor8]

Hi, thanks for the reply.
The lead acid bank has been kept up and batteries that needed replacing were replaced within the last 6 months, so there is still plenty of life in that battery bank.
The outback system is complete, from panels, to charge controller, two inverters, battery bank. I want to move the complete system to [primarily] run the workshop, but I am not in there enough to even use the capacity of the bank.
The new system is also complete. I am mainly curious if there is anything that would prevent me from feeding the new system with the outback's AC out, to utilize the 15kW of the lead acid battery storage as a backup when I use up the 10kW that I have so far in the lithium bank.

 

[viccooper]

I don't see why not. It's kind of inefficient but it doesn't seem that much different than charging an EV from a PV system