Battery replacement lead to dead truck....twice

To clarify, the dude that parked the car somehow hit the ditch light switch. The covers were on, and the truck dead in the morning.

 

Thanks. I'll get into this with more time for detail today. I need to get a topped off battery first. I'll check it at the shop later when I go to swap.

 

13.9 - 14.0 is what I see when I am driving. I think your charging system is working fine. If it were me I would focus my efforts on the battery itself and what may be draining it. Check out the vid below... dude explains testing for parasitic draw very well (I linked it starting at 3:25 which skips all the preamble). One safety consideration: be sure to remove the negative side of your battery when putting your multimeter in series (he goes into this in the video). If you accidentally short ground to ground nothing will happen. If you remove the positive side of your battery to test for parasitic draw and one of your multimeter leads shorts to ground you may create other problems in your electrical system.



Edit: if you replaced your lead acid with an AGM battery and did not change the charging specs in your tune this is most likely the culprit. AGM batteries are designed to charge at 14.6 - 14.8 volts so you are not feeding your new battery the voltage it needs to charge up. Source Sorry I missed this detail. When you said you see 13.9V at the battery, my initial response was in the context of a factory, lead acid battery. Go back to the auto parts store, get a group 24F lead acid battery and you will be good. That or change the tune in your ECU so your electrical system charges at 14.6 - 14.8 volts.

 

His Post says he went from the Factory Battery to AGM and back to a regular flooded battery and still is having the same issue.

 

I missed the part where he received a loaner flooded battery. Thanks for that, my miss.

Below applies still then. Check parasitic draw. Also: any number of things could be wrong with the loaner lead-acid battery (not enough electrolyte, or any number of things). If OP is in an extreme climate, battery issues will be magnified as extreme cold and extreme heat are no bueno for batteries. If his charging system is putting out 13.9V and is able to carry the electrical load of the Tacoma whilst driving the alternator is not the issue in my opinion. I stand by my original recommendation of checking the battery itself and the taco for parasitic draw.

 

Which of the 3 batteries involved are you suggesting he check? I think we ruled out the battery a long time ago and since the charging voltage looks fine as well, I’m voting for a parasite draw caused by one or more of the aftermarket electrical accessories.

 

Initial battery was toast and is gone so no needy checky. AGM battery was not being charged because duder didn't change his ECU tune to charge the AGM at the proper voltage so no needy checky. Loaner battery could have any number of issues due to it being a loaner. The battery I would check is a freshly charged lead-acid that duder exchanged his AGM that he returned to the auto parts store.

Things to check:

1. Is the new lead acid properly filled with water? Check the fill holes - water should be ~.5 in to 1 in from the top.
2. Has it been charged? What voltage is it reading before being hooked into the taco? Somewhere between 13 - 13.7 should be good

If the above check out on the new lead acid, then check parasitic draw. First battery could have been torched - I don't know duder's climate - we could expect 1/2 performance from our fresh one and done batteries back in the day for the newer RT1523E radios in extreme cold climates. Photographers will tell you the same thing on shoots.

This really isn't that complicated, its just where OP decides to start. The battery is the easiest thing to check which is why I suggested starting there. Parasitic draw would be the next thing and finally, since duder is in there already it cannot hurt to test the alternator just for funsies.

 

In my mind the jury is still out on whether the first battery was toast and on whether the charging voltage was not adequate for the AGM battery. Also, the described behavior suggests all 3 batteries went dead while the truck was parked for a period of hours. Although its not clear if the battery was not dead at the time the truck wad parked, all other evidence leads me to believe his aftermarket accessories are draining the battery, albeit it seems like it was discharged way too fast.

OP, one tip…. If you are having battery/charging issues, try to start the engine immediately after you park it to determine if the battery is charged rather than waiting until you have someplace to be.

 

You could be right, too many variables to account for. This whole conversation has me considering a m-LVD Voltage Disconnect from Blue Sea Systems. It would have saved OP if his accessories were wired through it. I have ditch lights and bumper lights on order and I think this discussion convinced me to wire a low voltage disconnect between my aux fuse block and the battery just in case someone leaves my accessories on.

 

Thanks for all the help folks. It's a drain on the battery. Taking from several of your suggestions, I checked the new AGM battery voltage and it was fine immediately arriving home. Removed the battery cables and let it sit for a while (I'm not very savvy...) And it floated on down to 12.7v after an hour or so. Reconnected and noticed a very faint buzz from the engine. I removed the cables from the battery again. .pulled the fuses from the ditch lights and light bar..no change. Took off the neg winch cable (which I neglected to include in my original post). Winner. Buzzing gone. I'll have to inspect the connections there, it's definitely the (hopefully only) draw.

It was so faint, with my normal background noise of dogs and music in the garage I didn't hear it until it was a quiet environment.

I guess it's a coincidence that I went banging around the river and canyons on Sunday and got a new battery on Monday.

Thanks again to TW. I learned alot reading the posts and watching the videos you guys sent my way. And that low voltage cutoff looks interesting. I may use this to tell the wife just how necessary it is!

 

Ideally your winch should have a battery disconnect but it sounds like something is up with the winch electrical

 

Hey man, nice work! One thing: that low voltage disconnect will only work for lower amp draw circuits (lights, stereo, gmrs radio, etc.). Depending on the winch you run and the load you place on it, you could pull up to 400A. Do NOT wire a winch through that disconnect as it is only rated for 65A. Your best bet is to wire a winch disconnect like this FJ cruiser bubba did.

 

Always look first where the human was last
It never fails, it’s almost always mods or damage

 

TBH, the lazy part of me thought about somehow switching the winch at first. But I gotta find the short. If I hadn't already had two Tito's and tonics, I'd be out there right now, lol
It's probably still a great idea bc this issue snuck up on me.

 

I'm learning that!

 

Hey it happens to the best of us!
We all want to assume it’s okay, but it’s a good place to start, you’ll know that next time. Enjoy your spritzers and don’t drink n drive!

 

It will shortly! Thanks!

 

I have one. Use the right battery and see how it goes.

 

the bad battery might have done something to the alternator.....just an idea

 

So....it isn't just the winch apparently. I diconnected that and the aftermarket lights from the battery and woke up to a dead truck.

Just finished testing all the mini fuses under the hood. Two stand out. ECTS reads 6.39v and EFI 1 reads 6.59 with the truck off. If it matters, the battery was pretty low (7.11v) by the time I got to those fuses that gave the readings. Thing is, with those fuses removed, the battery is still discharging. So I'm assuming there's yet another leak somewhere.

Are these two systems (ECTS and EFI) giving me abnormal readings? I'm learning here.