edward t--I have to say one thing, the worst chase my tail troubleshoots I have every dealt with were failed on install electrical items. Granted it sounds basic, but it's true. Hats off to you stupidattimes, your user name has been used by all of us at some point in time or another. I'll give you a good one. I had a 5 series 4Y truck that would run hot and at times overheat. No leaks other than the overflow, pump bearing and seal good, fan turned in the right direction and facing the right way, rodded out the radiator, R+R stat, blew-out reg coolant lines and block ports, shroud tight and in place, timing correct, tune up kit good. This unit was at a grout manufacturing company, burp plug would spit as it should. No luck. The only thing left was the water pump. Finally and lastly out of sheer frustration I pulled the water pump, which had a good bearing and the front seal was nice and tight. I found the impeller on the pump,(which was steel, not cast iron) had been worn and it resembeled a 5 inch circular razor blade!!! We all fall short, and I realized then I could'nt fix the crack of dawn!!!!! later bro

Far be it from ME to want to save Toyota from getting a reputation for bad batteries, but especially since this is the second battery to go bad in the same fashion, do yourself a favor, and humor me, get someone to tighten the alternator belt, or replace the belt, and check for free play in the water pump pulley.
Unless of course you are having the Toyota dealer's techs do this repair, in which case, after the first call it all ought to be a warranty of the first battery anyway, since they should be well trained enough on the #1 brand of forklifts, to know to make these checks without us having to suggest it to them..

As we all have done at one time another, we forget to start with the basics - so don't feel you are alone.

Like we are often told "All men are alike."

Well after replacing everything you can imagine the problem was the brand new toyota battery was faulty. It was not holding a charge large enough to start the lift but when you put a volt meter across the posts it would read 12.6v

I would go with the negative side of the circuit, as far more the most likely culprit, but some other possibilities include a distributor timing issue [if this is not a "computer emissions controlled" system], and a loose alt. belt* not charging the battery enough, (but charging enough to make the dash light go out) and if it is an LPS version truck, I would check voltage drops between the LPS disconnect switch and Alt output and battery posts.
* the alt. belt may also not pull strongly enough on the alt. to handle a loaded alt if the water pump is starting to fail at the water-pump bearing.

It could be a tight engine or transmission.

Replace your ground cable and put the lug end on the top retaining bolt for the starter. Also check and see if it has a factory solinoid wire on it and inspect for wear. If its a newer Toyota and has a low side ground to the head right above the dipstick, check the crimp on it. The factory had issues with hard starts due to a weak ground supply for all of the relays, one of which turns your LP fuel solinoid on. If the solinoid is itermittant, your operators will burn out the starters trying to start it.

sounds like a bad ground. Pull all of them off and clean them, inspect ground cable for internal corrossion (swollen and stiff spots under insulation).