Here in Australia we are sort of cut off from ready supplies of Solo batteries and all mine are starting to fade with age.
So I have been reading with interest anything that might fix this situation short of pulling the guts of the Solo and putting it into a new frame.
I kinda like my 2 Solo's.
So... ideally it would be nice to grab any new 5200 4S and use it to power the Solo.
But the battery information is critical to the safe operation.
I certainly wouldn't want to be flying around with no battery info.
In tinkering in the workshop I came up with this solution :
Taking the circuit board out of an old defunct battery, adding an XT60 and a balance plug to it, printing a small case to enclose it in, and we have:
Any 4S battery in a Solo.
The Hyperion 4S 5000mAh here fits perfectly.
Now the tricky part was to find out how to reset the SBM (Smart Battery Monitor) to be aware of the new battery capacity.
I noticed first that when turned on it was flashing a single LED, which was the capacity left in the old battery pack before disassembly, and this gave me a clue.
The SBM has a memory, so how do I reset the memory.
It turned out to be simpler than a lot have hypothesised on the forums.
With the SBM turned on, unplug the battery and balance lead.
Then plug the battery back in, followed by the balance lead, and the monitor is reset.
This will also happen when you change batteries if you don't turn the SMB off while changing batteries.
If you have it turned off, with say 2 LED's alight from the previous flight, and you put a fresh battery in, you will see only 2 LED's.
Now leave it on, unplug the battery and balance, plug the battery then balance back in and it should reset.
Works for me.