2020 TRDOR Eating OEM Batteries

Hello bright minds of TW. I'm trying to troubleshoot a little electrical issue and figured it'd be worthwhile to consult the brain trust.

Worth noting that I have the SQHD battery terminal kit installed; this is somewhat important later.

At my 5k mile service, which I did real late (really around 9500 miles), Toyota replaced my original battery, stating that it failed their battery test. Strange, I thought. I had assumed that they would have essentially just "skipped" the 5k mile service, and gone straight to the 10k service. The oil change is all I really wanted, and I didn't even get that! Irritating, but I made a service appointment for a couple weeks from then.

I just had the 10k service appointment yesterday, and to my surprise the new battery once again failed their battery test. Voltage looked alright (12.70V), but they only measured 380 CCA, down from the listed 575 CCA. This time, they complained about my "aftermarket accessories" installed on the battery, which at this point are just the SQHD battery terminals. They would investigate, for the low low price of their tech rate + parts. I figured I'd take a stab at diagnosing the problem myself, which brings us here.

After letting the truck sit overnight, I measured a voltage of 12.36V this morning, which definitely seems a little low for a brand new battery. Then, with the engine running, I measured a steady 14.1V, which seems perfectly normal. I turned the truck off and let it sit for a few more hours, and did a parasitic battery drain test between the negative battery terminal and the disconnected negative battery cable lead, measuring ~0.6A, which seems quite high. I'm struggling to think of how this could be related to the battery terminals, which are the only thing that's changed. Any thoughts?

 

Interesting to note, if I let the battery drain test sit for a few minutes it eventually drops to 0.14A, which is closer to reasonable. Maybe just components starting up when I “reconnect” the battery through the meter, and then re-entering a sleep state? Reading a bit, it seems like that’s not a totally unreasonable drain value for a newer vehicle.

 

At what point did you install the new terminals?

Just a thought - I had a Jeep that was eating batteries like this. Turned out to be a bad battery connection.

 

Just a few weeks ago; so right before my first service where they told me the battery was bad. I wish that I had taken a reading of everything before installing new terminals. What was the weak point of your battery connection? The only thing I could think of is the new crimp terminal I had to add for the negative cable going back into the wire loom, but it looks perfectly ok from a visual inspection. Nice and tight.

 

I had my OEM battery replaced at 50000 klms and then 1 year later I took it back to Toyota to troubleshoot the replacement because my tire mechanic had just done a load test and it failed.
Toyota said it was borderline so they did a slow charge and tested again stating it was ok.
So the next day I just bought a new Eliminator battery from Canadian Tire instead of waiting for it to fail on me again on a Monday morning before work. The new HD battery starts the truck much quicker and the lights don't dim when I start it now.

 

A look at the new terminals

 

50,000 kms and then a year later is still pretty quick, but this is only a week and about a couple hundred miles. WAY too fast for something to be going wrong with the battery itself, unless I just got really unlucky with two bad batteries in a row.

Does anyone know what the expected parasitic battery draw for a 3rd gen would be, roughly? I'm suspicious of the steady state 0.14-0.15 A that I'm reading.

 

Did you do an ohm test between the + terminal and the main fuse box? Also, the - terminal the body ground?

 

Go to the parts store and buy a couple of the lead terminals. Not the cheapest one but next grade up. I bet your problem will go away. I couldn't see any issues with my terminals either and I'm an electrician.

 

There is a parasitic draw and what you stated of .15 seems within spec.

 

What was the reason for changing the terminals on such a new vehicle?

 

I'm not sure what parts you mean. Something to replace the wiring I have in the truck?

 

Eventually going to add a house battery in the bed, fed through a 60A breaker and Renogy DC-DC charger. These terminals give me the ability to add accessory wiring more easily.

 

Haven't done one between + terminal and the main fuse box yet, but did perform one between neg terminal and body ground. I measured ~6 Ohm with the battery connected, but down to 0.6 Ohm between the loose terminal (e.g. the end point of the wiring loom) and the body ground with the battery disconnected, if that makes sense. I was struggling to figure out why there'd be a difference.

 

Ah, I see. Might be worth a try, although ultimately I'd like to get the terminals that I have on there working. I know a number of guys that run them without problems, so it doesn't seem like it's something inherent to their design. They're nice billet aluminum terminals.

 

Let me understand here: You're reading a parasitic draw of 0.15 A? That is 150 mA (milliamps). That is way too high. Typical draw (after a couple of minutes and ECU/modules go into "sleep mode" is 0.050 A or 50mA (or less). That is: 50 milliamps

First step: remove each and every aftermarket modification. Check your current draw. If it's still high....
Without a wiring diagram, I suggest you start removing fuses, one at a time, and observe when current draw drops down. You'll then at least have an idea of which circuit is the culprit. Good luck on your search.

Do check and clean your battery connections too. I use a piece of emery cloth in case you don't have the battery brush thingy...

 

I'll try another draw test, this time giving it a good 10-15 minutes before reading to make sure there isn't some system that's starting up right after I essentially re-connected the battery with the meter that's pulling an abnormally high current. I found this document to do a proper parasitic drain test that I'll follow.

I'll also check out the terminals again, but these are brand new, nice billet aluminum terminals. I'm pretty positive it's not a dirty connection.

We'll see how it goes!

 

Good luck!

Lot's of good information on Page 4 of the attachment...

Unfortunately you'll have to be the detective here, there are very few good electronic techs in any repair shop. If you need the Electrical Schematic you can go on TIS and get them. The cost is, I believe, about 15 bucks for a 24 hour subscription and you can download as much as you need.
I'm an old electronics hobbyist who happens to be a gearhead...I don't trust any dealership to work on my electrical stuff....

 

Don't forget the hood switch, door switch and that the truck runs the fuel pump (for a second to prime the system) every time you open the door.
You can close the latch on the hood and it should be ok.
You don't need the door open to check draw.
.050 amps draw should be max. Most cars are around .035 or less.
Also pulling fuses to find the draw will cause CAN BUS systems to wake up and give you false readings.
Use this method https://www.youtube.com/watch?v=lRcj1fQcWwU to find it. It's the best method to find parasitic draw on new cars and truck that I found in 28 years of fixing them.....

YMMV RON

Edit- I see Toyota says to pull fuses. Try that 1st, it's quicker....