Today my l200 died on me like I had turned off the ignition switch. I tried to restart and I had lost all power. No dash lights, or power windows. I turned the key and ... nothing. The engine didn't turn over nor was there even a clicking sound. I towed the car home. Once home, I checked the battery ( with the car not running) and it was 10.4 volts. I got a jump starter pack and jumped the car. It started right up. Checked the battery and it was showing 14.4 volts. With the car turned off the battery now shows 12.8 volts. I have turned it on and off multiple times and driven it for 20 minutes with no further problems.
Personally, I don't think it's a battery problem because I've not seen any slow starts. It always starts instantly.
--A couple more details. Two weeks ago the car wouldn't start. I rocked it back and forth and it fired right up. With todays incident, I tried rocking it but it made no difference. I don't know if there's a connection between that incident and today.
Any thoughts? I'd love to hear them!

 

Load test that battery before it decides you had enough warnings and leaves you sitting.

 

Thanks for the advice. I replaced the battery after it tested defective at Advance Auto.