Bad Battery?

[Eric_Phillips]

I have been having troubles with the battery on my 2010 F150. It doesn't get a lot of use so the battery is usually low when I need it and I thought it was something in the electronics slowly draining the battery. When I picked it up from the shop yesterday after getting it's inspection I turned the key and it turned over twice then clicked. The guy came out and jumped it and asked if this happens often because he had just checked the battery and it passed. Last night I put the charge on for several hours. The meter was in the red when I started and at 100% when I took it off. This morning I start it and back up to the trailer. I turned the engine off because I needed the keys. When I was ready to start the engine again it barely turned over. I pulled it up to the garage and the multimeter says 12V. I put the charger on and it first read about 25%. Then you could see the needle on the charger slowly move up. After about 30-60sec it was at 100%. I am thinking this is a battery problem not an electronics problem. Does that sound correct?

 

[ultrarunner]

Sounds like a battery... can swap with known good battery and use process of elimination?

I have a battery load tester with a meter that also indicates starter draw and alternator output... makes quick work of diagnosing problems.

6 years on a new vehicle does not sound all that out of line... especially one that does not get used a lot.

 

[444Powerstroke]

yes, you need a new battery. Been there, done that.

 

[k0ua]

Many of us don't have load testers, but a simple substitute is to measure the battery voltage directly on the battery posts..NOT the battery clamps, but direct on the battery posts while attempting to start the truck. This will measure the battery under load and will tell the tale if the battery has a high internal resistance.

Just because a battery charges up to around 12.5 volts does not mean it is good. You have to have a voltage reading under load. Batteries must deliver power into a load to have any value. In words, they must be able to maintain sufficient voltage to spin the starter at a sufficient RPM while that starter is drawing a large amount of current from the battery due to the starters low resistance.

Correct voltage while pulling lotsa current, means lotsa power delivered into the starter to be able to shoulder the load of that engine with its huge compression ratio.

 

[RalphVa]

I went through something similar on my Tacoma. It doesn't get driven much either.

Was keeping a trickle charger on it off a timer. Finally got tired of that and took it to my battery place and replaced the battery. No problem now.

Ralph

 

[k0ua]

Modern cars and trucks with computers do draw some parasitic current and if not driven for a few weeks can run down the battery, especially if the battery does not have the capacity that it once had. For those outside a simple solar charger on the dash can keep those batteries up, or if stored inside, then a trickle charger on the AC power can be your friend.

 

[Eric_Phillips]

i guess I will go get a new battery. Does anyone have a suggestion on a solar charger? I think it will be a good Idea when I get the new battery to put it on solar charger to keep it charged during down times. When I have looked for them in the past there seemed to be a wide variety in terms of capacity and price.

 

[skylarkguy]

I just replaced a battery in my truck that i thought was 3 years old...but was 13 years old....it had 12 volts but only about 110amps under load...pretty good run for a battery.

 

[k0ua]

i guess I will go get a new battery. Does anyone have a suggestion on a solar charger? I think it will be a good Idea when I get the new battery to put it on solar charger to keep it charged during down times. When I have looked for them in the past there seemed to be a wide variety in terms of capacity and price.

I have a couple of these types

Amazon.com: Sunforce 513 1-Watt Motorcycle and Powersports Solar Battery Charger: Automotive

 

[Eric_Phillips]

After sitting over night the truck battery had troubles turning over the engine. I got out the multimeter and it said 11V. I had my daughter turn it over and the voltage dropped to 5V. New battery time.

k0ua, thanks for that reference. That looks like an inexpensive alternative.