Received from fogstar this morning:-
If you were to fit a charger capable of charging two batteries to 10kwh in this 4 hour window, they would be fine as if you parallel two batteries, the max charge/discharge will double.
The cheaper of the two would be the one I would recommend as the set-up is much easier. The 15kwh bundle will require more time to install as this is made up of 3 x 5kwh batteries. Some people opt for this as you can increase the power in smaller amounts over time, instead of having to increase by 15kwh with each battery, you can just increase it by 5kwh if needed.
Kind Regards
Lyndsey
The only person who got all his work done by Friday was Robinson Crusoe.
Anything i post over three lines long please assume it is an article lol.