Battery Drain Problems

We purchased a 2019 SR5 with 57K mi this past weekend.

- We drove it once Sunday.
- Monday took it back to the dealer for a minor brake repair -- the emergency brake was rattling.
- Then my wife picked it up and went shopping, spent 30 minutes in a store, came out and the battery was dead.
- I measured voltage 11.x and then jumped it and it started, and then drove it 30m home. The battery voltage when running measures around 13.5V.
- The next morning, it started fine -- several times.
- While the vehicle was off, the current draw on the battery was measured with a clamp meter around 300mA initially, then dropped down to 130mA.
- A couple of hours later, draw measured less than 50mA and started fine.
- Took the battery to Autozone, and they said the battery tested OK, said it did not have full charge, and suggested it is a charging or drain problem.
- We have the battery on a charger now and will try again.

Any thoughts on where to go with this?

Also, I would like to figure out how old this battery is -- is this original battery, or has it been replaced?

Appreciate any suggestions.

 

Looks like it could be the original battery. If so, it's exceeded it's normal life span.

 

I agree.

 

It's the original battery. Everything's is in line, battery voltage ~13.5V running, ~200-300mA draw for a bit than should drop down to under 60mA.

It may have sat for awhile so a good trickle charge is good. Definity think about replacing the battery though.

 

I you replace the battery, and that current drain is still there, yank the fuses one at a time and see if the current drain stops. That will isolate which circuit is causing the drain. Also, yank the relays as a sticky contact might be powering up a circuit. Keep us posted.

 

Thanks for all the advice -- new battery is going in tomorrow morning, and then we'll see what happens ...

 

Good call! The battery in my '19 was already getting flimsy two years ago. I replaced it in January of '22. These things seem to go through batteries pretty fast.

 

- Installed new battery.
- not-running battery voltage is 12.7V
- running battery voltage is 14.3V
- drain current after running is 300mA for a few minutes, then 130mA. Half an hour later still 130mA
- 1.5hr later, the current was measuring 10-50mA
- as I was watching the meter (above), I heard a relay click, and the current jumped up to 0.7A. After about a minute, it dropped to 140mA. Several minutes later, still 140mA.

What is it doing when the current jumps up to 0.7A?

The hood is open and the vehicle has an alarm system, so wondering if it is something related to the alarm.

Thinking of rigging up a current data logger and log current over time ...

 

measured again:

- current is less than 10mA -- in the noise floor of the meter.
- voltage is 12.7V

There is some impressive power management in vehicles to get the current that low.

 

The fuel pump turns on briefly after 1/2hr, so that could be the jump.

Thank you for the details. I too have an alarm and have been dealing with a parasitic draw for a year (~130mA) and i get similar readings but never down to 10-50mA....

What car alarm manufacturer?

 

Culprits may be our winch, compressor?

 

No. I'd doesn't matter if they're modified. Although, a winch can certainly put a strain on the battery, as well. Newer vehicles seem to have a lot more parasitic drain than older vehicles. Or, maybe batteries just aren't made as well as they it used to be. Maybe it's a little of both.

 

Newer vehicles definity have a higher parasitic draw with there active power management systems. Batteries are definitely better, but they seem to be less consistent.

 

Good choice to change the battery. Just don't trust the advice of the parts counter person. Most are not capable of knowledge beyond what the screen tells them.

 

No problems since the new battery

 

My 4Runner just has the stock alarm system that came with the vehicle -- activated when you lock the doors, and then if a door or hood is opened while the car is locked, then the alarm sounds. You can test this by getting in vehicle, locking all the doors, waiting a minute or two, then opening a door. Since the vehicle was not unlocked from the outside, the alarm will sound. It is a nice system -- very transparent to normal operation.

 

My original / factory battery in my 2006 Tundra lasted a little over 8 years. I replaced it while it was still working just fine. But I did sense that it had been cranking slower, so I errored on the side of caution and replaced it. It never let me down anywhere. Amazing.