Convert 24v Hubble AM-4 into 48v Hubble AM-3 or other magic options

Hi everyone. Some input, ideas, alternatives please!!

I currently have 2 Hubble AM-4 24V lithium batteries for sale in the classifieds section.

They are basically brand new. About 12 cycles on them each.

I have a 48v Sunsynk setup now.

I have been thinking what to do if the batteries do not sell. 24V is not in that big of a demand.

Obviously I cannot sell them for less than they are advertised currently and I cannot just pack them away.

So far I can think of 2 options.

Option 1:  

Purchase a basic 24v inverter/charger that will play nice with lithium batteries. As cheap and basic as possible. (Any recommendations would be welcome.)

Connect it to the Sunsynk aux port as generator/inverter in.

Use a 15A smart switch to turn on the 24v inverter/charger AC input (feeding from non-essential loads port on Sunsynk) eg from 09:00am to 17:00pm, limiting current to below 15amps. Should be enough for batteries to receive full charge easily.

Option 2: (bad idea, I know.)

Beg/plead Hubble PTY to sell me a 48v AM-3 BMS assuming the AM-3 was just a 24V AM-4 but with xS2P config. I have asked them before if there is no way for them to reconfigure my 2 batteries but the answer was no. Thinking of asking again…. You never know.

Try and get someone to convert the AM-4 config into 48V with a 48V AM-3 BMS. Obviously losing all warranties.

Any other ideas except options 1 and 2? Any other way to use the two 24v AM-4 lithium batteries with my 48v Sunsynk?