Attaching 24v battery to 48v battery using DC to Dc converter

[ahmad_solar]

So I have 14 kwh 48v LiFePo4 battery (DIY, EVE cells + JBD bms), I have another battery of 24v battery (Same, but using 8 cells), is it possible to connect this 24v battery to the main battery using Dc-Dc converter? I know there are some issues here especially that the capacity doesn't match and it will be hard to charge it correctly from the sun (without it draining the main battery).
So is this setup possible?

For context: My inverter is Deye 5kw
I don't mind having the 24v battery provide low power (e.g 100 - 400 w) so it will be only used to assist the main battery and extend it's life when I have high loads or when the sun is not enough

 

[LakeHouse]

Maybe, but you’d need two different dc-dc converters (a buck to charge the 24V, and a boost to get back to 48V), and disconnects/logic controllers for all kinds of scenarios (e.g., what do you do when both batteries are low, and the sun is shining? Charge both, or just the 48V? How do you implement that?).
In the end, this is probably not worth the cost and effort. Especially compared to the clearly better solution of just adding 8 more cells to get both batteries to 48V.

 

[TomC4306]

Especially compared to the clearly better solution of just adding 8 more cells to get both batteries to 48V.

This

 

[ahmad_solar]

Maybe, but you’d need two different dc-dc converters (a buck to charge the 24V, and a boost to get back to 48V), and disconnects/logic controllers for all kinds of scenarios (e.g., what do you do when both batteries are low, and the sun is shining? Charge both, or just the 48V? How do you implement that?).
In the end, this is probably not worth the cost and effort. Especially compared to the clearly better solution of just adding 8 more cells to get both batteries to 48V.

Yes I was totally thinking about the cost and it seems not worth it, the problem is I don't have 8 cells handy right now, but I will need to order some other tools for DC-DC conversion so I might as well order those 8 cells. However, I was interested to know if there is an exiting tool that handle this, seems there isn't
Thanks!