No battery tender. But the batteries are going bad, cells collapsing on the inside. What's causing this.

That is an odd one.......................:bump2:

buy a premium battery
what have you been using ?

buy a premium battery
what have you been using ?
highest grade available at advanced auto parts

highest grade available at advanced auto parts

Have the alternator tested so you can rule that out.

Advanced Auto will do it for free.

Have the alternator tested so you can rule that out.

Advanced Auto will do it for free.
The solenoid is stuck in. Starter and solenoid got extremely hot. Drained the battery immediately. I found the positive lead going to the starter melted onto the exhaust pipe. Possibly bleeding through but not a direct short. I'm going to replace the starter/solenoid then have alternator and regulator checked.
On the dash, I keep the readout in voltage. I've never noticed any spikes. 14.2 volts max reading.

Nice!

I was worried about overcharging. Sounds like you found the root cause. :)

You know I totally forgot that Autozone will do that for free.:thumbsup3: