Lately I've been trying to tackle some electrical issues in my truck, I noticed if I left the truck sit for a few days the battery would die.

After some investigation I found I had a parasitic drain.

I started going through all my electrical connections and found a couple bad grounds that I have since corrected, I also fused a few of my extra items that we running off the battery.

After finishing all this I tried starting the truck and nothing, hooked up jumper cables and all I got were clicks.

Took the battery to Autozone and it tested good and was holding a 65% charge.

Maybe it's just me, but 65% should be enough to turn over the engine.

They charged it to 95% and I brought it home and it started right up.

Do you think this is a battery issue, or do I still have something going on with my electrical system elsewhere?

 

Update: Truck started fine this morning and I took it to O'Reily's and the starter, alternator, and battery tested good.

I'm going to let the truck sit for a few days to see what happens

 

Your electric system should have a "battery saver" relay, usually behind the radio.
This relay cuts power to most circuits after about 20 minutes of key off.

This relay can cause a drain though, lol.

Best way to test for drain is to disconnect Negative battery cable connect jumper cable from Negative battery cable and battery post, start vehicle.
Shut off vehicle then close and lock the doors, windows open if you want.

Connect amp meter between Negative cable and battery post, disconnect jump cable(you must maintain power connection at all times or you will have to restart the test), you should now see the amps being drawn from battery on the meter.
You will have to wait 20 to 30 min. for the battery saver to kick in, this will tell you if you have a drain, I think .03 is spec, that info is available with a search

 

My voltmeter only has a resolution of 0.1 on the amps setting and it showed no draw.

I let it sit from Friday to Sunday and it had no problem starting Sunday evening.

I feel like the drain is fixed, but I still plan to replace the battery.

 

Do you or can you park where you can see the tail lights.

A "lazy" brake switch could cause intermittent dead battery issue, even a glove box or under hood light switch can do that, Battery Saver relay is suppose to prevent that though.

New battery will show 12.8volts(engine off), 100% life
after a few years it will show 12.5volts, 75% life
12.2volts is 50% life and time to shop for good battery sale, next cold morning may be a no start.

When they get down below 12.3v they can start self draining, a short in one cell drains the whole battery, symptom of this is when engine starts fine all day long but when left over night(10 to 12 hours) it won't start or barely turns over and starts, thats a bad battery not charging system.