Is my battery dying, or....?

So, Need a quick spot of advice.

Late last year, i picked up a new battery (Interstate MTP-24F) after the original one crapped out. Lately, i have noticed an issue where the voltage may look low (i have seen my ham radio report under 12), and at times, take more than one starting try to get the engine to turn over. It doesn't always do it, but there are times where it feels pretty close to not starting.

On Friday, i dropped by autozone, and their tester said bad battery. Watching my truck over the weekend (no use), my voltage (again, Ham radio wired right to it) went from 12.4 to 12.1. When driving, the reported voltage goes up to 13.5 to 14.1.

I'm going to take my truck by a battery seller to get it changed under warranty, but also.. should i be looking at anything else hindering the system? I don't notice any rough riding, though i will say i don't have the best MPG (average 16, but lots of city traffic driving). I appreciate any advice!

 

Clean your contacts. My boat battery was "dead" literally reading 0 to 2 volts on my multimeter. Cleaned the contacts and she is in PERFECT shape, 12.4 volts after cleaning. Clean the clamps too. also make sure the connections are tight after cleaning the posts.

 

The contacts looked good, but i guess ill get a second opinion from the battery shop. Any other ideas why it would go from 12.4 to 12.1 with no use (and not a freezing weather weekend either)?

 

does your ham radio pull power even if its off? A slow drain can definitely kill a batt over itme

 

While i must assume a new milliamps for the power button (soft switch, not mechanical) i have never noted a drain from it(at least above the background drain of other listening systems like the key fob, etc). The radio is a pretty common Yaesu FT-7800R; while my unit could be faulty, i haven't heard of any widespread complaints..

 

Eh just do the KISS method... and keep it simple, get that battery replaced first.

 

That's what I pushed for. The shop here said it was looking fine, and that 12.1v was fine.... but I have read other places saying that is way too low. So, I pushed for them to replace it (by warranty damn it ). I'll watch it from there and see what I get. If it still has issues, I'll have to look for other drain sources...

 

The real test is what it reads during starting. You can have a completely dead battery read 12-13v but put any sort of load on her and it falls on its face.

 

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You will only get below 12v reading if one cell is 100% dead.
So you can have near dead battery still reading 12V but as guy above wrote once you put load its dead.
try load testing battery otherwise replace it, because it sounds like battery is having issues.

 

Battery has been replaced (though, i am not impressed with it.. damn thing is dusty as hell), and read 12.1 before i started. Ill keep an eye on it. if this one does it too, ill suspect something else

 

If you replaced battery and have 12.1 again check voltage on battery itself, compare that to voltage readout.
its possible one of the relays is burn and has resistance when you turn key. Or maybe fuse partially damaged.

 

I still have my stock battery and have the same problem.
Check out my thread
https://www.tacomaworld.com/threads/2014-engine-start-up-trouble.366049/

 

One more quick addition - after looking back at the toyota maintained service logs, and not seeing a single tune up, i decided to bring it in for that too. The techs (while they can never be certain), believed that the plugs had never been changed. Admittedly, i purchased it used at ~60-65k, and was under the impression that it would have been maintained before being resold.

Not sure if it was the cause of my issues, but i guess that is another lesson with stealerships..

 

Spark plugs should be good for 100k miles. Dealer would never change them in a used vehicle unless the truck wouldn't run with them in it.
The real test of a battery is a drain test. Some parts stores will do that test.
In hot climates, a battery should be expected to last about 2 years. For that reason, lots of people buy the best warranty battery and get free replacement when they fail.

 

100K miles is only for the Iridium Plugs in the 2.7 Liter 4 cylinder engine.

The 4.0 liter 6 cylinder uses copper plugs and they are only good for 30K miles as per the maintenance schedule.

 

Given the wear, these are most certainly not iridium. When they pulled them, they found that the engine still had the factory NGK on one side, Denso on the other...
For what its worth, i attached a picture of one of the NGK plugs...

 

If the charging system is healthy, I suspect that you are undercharging your battery due to driving habits and aftermarket electrical load. If so, there is a gradual buildup of lead sulfate on the plates that is causing your battery to lose cranking performance and capacity. There are several remedies if this is the case, but first to confirm, fully charge your battery with an external battery charger and measure the voltage the next morning as a baseline. Then drive normally and remeasure you battery the next few mornings to see if the battery is fully charging. [Depending on your battery type, a fully charged battery will measure a minimum of 12.65 VDC or 12.8 VDC with a digital voltmeter.] If the battery is not fully charging, you can quick disconnect a small temperature compensated "smart" battery charger, like a Battery Tender Plus, to "'top it off" at night. A better solution is to replace the alternator with one that produces more power.

 

First, all batteries discharge over time (self-discharge). And probably more to the point, a lead-acid battery will build up a "surface charge" after driving a bit. But a surface charge is not the same as a normal "deep charge". It will bleed away fairly quickly. Testing a battery with a VOM right after driving will not give an accurate battery voltage.

Your issue sounds like either a battery or connection issue. And connection issues can be tricky to find. I had a dakota that somehow let corrosion get inside the battery cable itself. Even with the rubber sealed to the connector. Cut it back, green powder rather than bright copper wiring.

 

Well, i am keeping an eye on it at this point, and ill see how it behaves. I am actually kinda surprised no one said anything about the spark plugs. Looking at the one i posted, i wouldn't blame the truck for having problems starting...

 

If you are replacing battery, move up to at least a 27 (size in factory tow package), or measure width/length/height and put in the largest that will fit. Doesn't address what's causing the discharge, but will help battery life. My OEM is 7 years old and no problems.