"it's luquid cadmium sulfate "
Is that like turning a lead acid into a cadium battery then?
"bad as in excessive heat, gassing & plates worp & extra power ya know"
Don't think any of that is a concern. Any extra power used is probably offset by not paying money for expensinve additives, and using wind power or such would basiclly be free anyway. Not much cost if using grid power either.
"as far as to play with the acid, not realy a good idea.
i just ment to get the batteries identical.
to reduce them from self draining parallel batteries."
That will never get them identical because the problem is not the acid, it's the plates!
You need to learn how lead acid batteries work. I am tired and may not be exact here, but close enough.
Durring discharge the acid forms sulphates on the lead plates. Durring recharging the sulfates disolve back into the acid. Over time some sulfates will crystalize on the plates, then they do not disolve back into the acid as they should. This both weakens the acid and insulates the plate. What happens then is charging the battery become harder, the battery does not put out as much power also. You need to get the sulphates disolved back into the acid and off the plates to restore the abilty of the battery to charge and discharge correctly like when new. That is what pulse or desulphate and EDTA is supposed to do.
That is also why you should not mix the acids as you had said to do. You are not doing anything to the sulphates on the plates which are the actual problem in the weak cell. You either have a sulphate problem or you do not. If you have a problem then the acid is weaker than it should be, so if you mix half weak acid with full strenght acid from cells that do not have a problem, then what are you doing? You are diluting the full acid to less than full then putting it back into a cell that was fine, now making it weak. You encrease the acid strenght from the weak cell also, now if you get those sulphates off the plates and back into the acid in the weak cells you will have acid stronger than it should be.
SO, you have weak cells that are too strong and strong cells that are too weak, not too good I would think. Course maybe someday if all the sulphates ever disolve back into the acid in all cells at the same time, then if you mixed them you might get back to the original acids strenghts in each cell. But I would not count on it, and why bother all that work and danger playing with the acid to get back to were you started when it doesn't do anything in between really.
"would fresh acid be better?
what do you do with the old stuff?"
NEVER, as explained above it's the sulphtes on the plates why the acid got weak, new acid and then disolving sulphates back into the acid will make it too strong.
If you ever have old stuff, store it safely well marked, if you have a problem sometime like a spill or leaking battery you fixed, you can refill with the old used acid. Chareg the battery a few times to disolve any sulphates on the plates, then check specific gravity of the acid and if needed mix just a little pure acid to bring it up to the correct level.
For instance I had a friend that put a brand new battery that was too large in his car, it moved a tiny bit, rubbed the alternator fan, wore a hole in the battery, sprayed acid all over under the hood from one cell. Had I known then what I know now, I could have repaired that $60 new battery sealling the hole and refilled with used acid. Being new no sulphate problems so it would have been easy to charge it a few times then if needed add a little pure acid to bring the specific gravity to the correct level.
But that was many years ago.
Another time I had bought a brand new deep cycle, on the way home I slammed on the brakes to avoid hitting a deer. Next day I found the new battery dumped over and was empty. What a mess I had there! Only sulphates in that one was caused by just selfdischarge while sitting in the store waiting to be sold. It was easy to refill and use.
That's what I use old acids for if/when I have any. Other uses like making hydrogen but I won't go into that now.