You left the whole system completely off and ignored all that time?
If the cells were in good shape at that time, and stored 100% isolated from **any** parasitic loads, they may well be fine and last for decades more.
In which case they are now sitting at over say 2.5Vpc.
If they were drawn down to dead flat, then likely not good for anything, not worth much time spent (very carefully!) trying to resurrect them, unless as a fun science project.
Break the pack's parallel connections and measure per cell and report back. Do **not** just turn anything on, that may be the straw / camel.
Plus verify low resistance of interconnects, corrosion issues, should be done regularly, lots of check / monitoring / maintenance routines need catching up with before re-activating anything,
Personally I would've checked on the bank regularly and topped up any self-discharge, maybe less frequently once I got familiar with their behaviour, temperature effects etc.
Too big an investment to just allow it to evaporate. . .
If the cells were in good shape at that time, and stored 100% isolated from **any** parasitic loads, they may well be fine and last for decades more.
In which case they are now sitting at over say 2.5Vpc.
If they were drawn down to dead flat, then likely not good for anything, not worth much time spent (very carefully!) trying to resurrect them, unless as a fun science project.
Break the pack's parallel connections and measure per cell and report back. Do **not** just turn anything on, that may be the straw / camel.
Plus verify low resistance of interconnects, corrosion issues, should be done regularly, lots of check / monitoring / maintenance routines need catching up with before re-activating anything,
Personally I would've checked on the bank regularly and topped up any self-discharge, maybe less frequently once I got familiar with their behaviour, temperature effects etc.
Too big an investment to just allow it to evaporate. . .