I am looking for a bit of advice on my lead acid battery pack in my N/I EGT-150. The pack wasn't new when I purchased them about 8-9 years ago. I know it should be time for them to go to the battery graveyard.  This tractor has been setting for a while due to the OEM F & R Contactors finally giving up. Since replacing those I have been running the Pulse Tech desulfate charging system on each of the three 12 volt sub packs, (two deep cycle six volts each). The Pulse Tech system will only work with twelve volts so you just parallel them and it works great. One sub pack appears to be coming up as it is showing about 25% charge after 3-4 hours of pulsing.  The other two appear to be complexly dead and show as "bad battery" on the pulse charger.  As a test I thought I might try to put a surface charge in with my auto charger on each 12 volt set and then see if the Pulse Tech would help them. On the fast charge one set appears to be taking a small amount of charge whereas the other one did nothing.  After reconnecting these two back on the Pulse Tech they still won't begin to disulfate.  I see liquid rejuvenator products advertised on eBay which claim to work about 95% of the time on failed batteries. 

I am wondering if anyone in Elec Trak land has tried this and what your results have been. For the money it certainly would appear to be an economical if only short term solution. Then again it may just be time to purchase new batteries. I noticed that the lithium's are comparatively priced, however from what I am reading on this site it sounds as though they are pretty finicky on the amount of discharge they are able to handle without internal damage.  Beyond my Pulse Tech desulfating charger I am still using the EGT's on board "battery boiler" which has always done the job.

Any thoughts are most welcome.

Autumn Train in NW Iowa