1981 CB750 Not starting, battery discharging

[DRTP]

I bought a 1981 CB750 last fall. It had starting issues at the time. I had to do two roll-starts just to get it home. I did some work over the winter, including:

New battery
Replaced a bad stator
New regulator/rectifier

After all of this, I placed the battery on a charger overnight and expected that the problems had been solved. The next morning, I only got one crank out of the battery/starter and not enough to start the engine. I jumped it with my other motorcycle (A little 250 Ninja, that I originally learned on). It was able to run on its own from there; opposed to before I replaced the stator and R/R.

I didn't get to test the battery while running because the bike does not hold an idle and I didn't have two sets of hands. Stator has been tested showing 0.7, 0.7, and 0.6 ohms on the three wires. Battery initially has 12.3 V after charge but drops below 12 after start attempt. I'm wondering if there a ground in the circuit somewhere or whether I have somehow killed the battery.

Please let me know if there is more information I can provide you with and Thanks for any advice you could give!

 

[mydlyfkryzis]

A fully charged lead acid battery should have 12.7 to 12.9 volts sitting. It may show 13.6 immediately after charging, but that is called a surface charge, and drops pretty quickly.

if you are showing 12.3 volts right after charging, your battery is bad...Anytime a lead acid battery drops below 12V, the life and capacity is shortened. Dropping below 11 volts can shorten the life and capacity more than 50%.

Maybe the battery has warranty left?