Dead Battery

EOD Guy

EOD Guy

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When I started my air compressor install, I measured the voltage on the "jump start terminal" under the hood and got 12.5 volts or so. Finished my compressor install, everything went as it should. I also install a 40 amp manual circuit breaker (which I always put on all my vehicles) which allows me to cut power by manually tripping the circuit breaker. When out this morning to run some errands and the battery was dead as a door nail. Opened the door popped the hood, C/B was still tripped and measured 8 volts on the jumper terminal. I had just gotten back from a 900 mile trip, so the 12v battery should have been at full charge.

Now what was interesting was absolutely nothing worked in the vehicle, couldn't unlock the rest of the doors, couldn't open the rear hatch etc..... I hooked up a charger to the under hood jump terminal and after 15 minutes, all the functions started working again.

My conclusion: Installed a battery tender pig tail, which will allow me to easily connect a jump box and Purchased a jump box. Without power you're not going to get the rear hatch open without extreme difficulty in order to replace the battery (if needed). This is the second new Toyota vehicle that the battery has failed within weeks of me owning them.

My personal rule with batteries......... If it goes dead, I check to make sure there's not a light that was left on etc...... charge it and if it goes dead again within a week or so, I replace it. Nothing worse then being stranded for a $150 battery.
 
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Sucks on the dead battery. Always a crap shoot. I've had one die after a heat wave (my commuter has the battery up front) and some that had no signs of slowing down after 8 years. That was not common however, as I like swapping batteries at year 5 regardless of condition.
 
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Below are the TSBs concerning the 12v battery and dealer's actions on storage.
 

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  • Battery Long-Term Vehicle Storage Guidelines, T-SB-0026-23.pdf
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  • Battery Maintenance During PDS, T-SB-0024-23.pdf
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  • Battery Maintenance for HV-BEV and Auxiliary BatteriesT-SB-0025-23.pdf
    484.5 KB · Views: 86
I thought you just needed a quick power to the hybrid terminal - then the 12v would charge from hybrid. That’s how Prius, etc. work.
 
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In my case it took about 10-15 minutes with the charger before the gauges started working again. Then about 7 hours to attain a full charge on 12v battery.
 
Did you put power here - the red + in the fuse and -ve on the metal? This is what I’ve been told brings the computer online
 

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EOD Guy said:
Below are the TSBs concerning the 12v battery and dealer's actions on storage.
Click to expand...
Very interesting and thanks for the TSB’s. My shop foreman at my Toyota dealer has always tested my 12V in 2001 4R and often says something like “battery is somewhat low put a charger on overnight”. Pretty much with all of my cars which are rotated they are on battery maintainers on and off usually the 1.5A, 4A battery tenders and the 5A CTEK.
I’m unable to drive the LC for about 10 days so I put a 4A battery tender on connecting to the jumper positive terminal and the bracket negative as in manual and it’s in “maintain mode” now after charging up for about 4 hours. It’s in garage with hood propped open. I think it says this is OK in the manual for 5A or less, but the TSB’s favor at the battery which is fine but you have to reset everything.
Do you see any problem with theprocedure I’m using?
 
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brianz said:
Did you put power here - the red + in the fuse and -ve on the metal? This is what I’ve been told brings the computer online
Click to expand...
Yes under the plastic cover is the jumper terminal. No convenient ground lug tho'
 
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LCMud said:
Very interesting and thanks for the TSB’s. My shop foreman at my Toyota dealer has always tested my 12V in 2001 4R and often says something like “battery is somewhat low put a charger on overnight”. Pretty much with all of my cars which are rotated they are on battery maintainers on and off usually the 1.5A, 4A battery tenders and the 5A CTEK.
I’m unable to drive the LC for about 10 days so I put a 4A battery tender on connecting to the jumper positive terminal and the bracket negative as in manual and it’s in “maintain mode” now after charging up for about 4 hours. It’s in garage with hood propped open. I think it says this is OK in the manual for 5A or less, but the TSB’s favor at the battery which is fine but you have to reset everything.
Do you see any problem with theprocedure I’m using?
Click to expand...
That's my plan. I installed a battery tender pig tail under the hood for ease of hooking up a tender. I rotate which vehicle I drive and some haven't been driven in 6 months...... so tenders are a thing for me.

On a side note, my CTEK charger was getting very hot when attached to the jumper terminal under the hood. I switched it to a direct connection to the battery terminals, still got hot but not as bad. I think I'm going to install a second tender pig tail directly to the battery.
 
EOD Guy said:
That's my plan. I installed a battery tender pig tail under the hood for ease of hooking up a tender. I rotate which vehicle I drive and some haven't been driven in 6 months...... so tenders are a thing for me.

On a side note, my CTEK charger was getting very hot when attached to the jumper terminal under the hood. I switched it to a direct connection to the battery terminals, still got hot but not as bad. I think I'm going to install a second tender pig tail directly to the battery.
Click to expand...
OK thanks. Yes I could connect right at the battery maybe have cord going in at rear passenger window.
One thing very interesting about the pigtail install for ease I did that on my hybrid F150 and the wind currents under the hood at high speed blew it around and chafed the insulation! Weird and it was secure! So most cars I connect at battery. One car, a Porsche cayman, has a dedicated 12V connection in passenger footwell so I use the CTEK 12V cigarette lighter adapter.
As for heat yes it’s a problem especially on hot summer days. Almost seems to me the CTEK scales current back with ambient temperature. I made sure the LC got into maintain mode and was cool before I left.
 
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LCMud said:
OK thanks. Yes I could connect right at the battery maybe have cord going in at rear passenger window.
One thing very interesting about the pigtail install for ease I did that on my hybrid F150 and the wind currents under the hood at high speed blew it around and chafed the insulation! Weird and it was secure! So most cars I connect at battery. One car, a Porsche cayman, has a dedicated 12V connection in passenger footwell so I use the CTEK 12V cigarette lighter adapter.
As for heat yes it’s a problem especially on hot summer days. Almost seems to me the CTEK scales current back with ambient temperature. I made sure the LC got into maintain mode and was cool before I left.
Click to expand...
There's plenty of distance from the jumper terminal to the grill and it tucks nicely between the air cleaner and the PDC box so I don't think it'll have any movement at all. I think the under hood pig tail will be ok for the tender. I'm just thinking if I need to charge a dead battery a pig tail (10 gage) would be good for the rear. The red protective cover over the pos battery terminal did not fully open and I had to force it open enough for clearance in order to attach the larger charger clamps.
 
EOD Guy said:
When I started my air compressor install, I measured the voltage on the "jump start terminal" under the hood and got 12.5 volts or so. Finished my compressor install, everything went as it should. I also install a 40 amp manual circuit breaker (which I always put on all my vehicles) which allows me to cut power by manually tripping the circuit breaker. When out this morning to run some errands and the battery was dead as a door nail. Opened the door popped the hood, C/B was still tripped and measured 8 volts on the jumper terminal. I had just gotten back from a 900 mile trip, so the 12v battery should have been at full charge.

Now what was interesting was absolutely nothing worked in the vehicle, couldn't unlock the rest of the doors, couldn't open the rear hatch etc..... I hooked up a charger to the under hood jump terminal and after 15 minutes, all the functions started working again.

My conclusion: Installed a battery tender pig tail, which will allow me to easily connect a jump box and Purchased a jump box. Without power you're not going to get the rear hatch open without extreme difficulty in order to replace the battery (if needed). This is the second new Toyota vehicle that the battery has failed within weeks of me owning them.

My personal rule with batteries......... If it goes dead, I check to make so there's not a light that was left on etc...... charge it and if it goes dead again within a week or so, I replace it. Nothing worse then being stranded for a $150 battery.
Click to expand...
Looks like not letting the hybrid battery directly power the cars electronics is a safety choice. But based on the article below, some manufacturers like Hyundai integrated a “push-button” to jump 12v battery using the hybrid battery. I wish Toyota also added that as an option.

www.caranddriver.com

Why Do Electric Cars Still Use 12-Volt Batteries?

Your electric car or plug-in hybrid is propelled by a sophisticated lithium-ion battery, but you'll probably also find a lead-acid 12-volt battery in there somewhere. Don't throw away your jumper cables just yet.
www.caranddriver.com www.caranddriver.com
 
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Tripod1404 said:
Looks like not letting the hybrid battery directly power the cars electronics is a safety choice. But based on the article below, some manufacturers like Hyundai integrated a “push-button” to jump 12v battery using the hybrid battery. I wish Toyota also added that as an option.

www.caranddriver.com

Why Do Electric Cars Still Use 12-Volt Batteries?

Your electric car or plug-in hybrid is propelled by a sophisticated lithium-ion battery, but you'll probably also find a lead-acid 12-volt battery in there somewhere. Don't throw away your jumper cables just yet.
www.caranddriver.com www.caranddriver.com
Click to expand...
That would be sweet!
 
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Rumor has it.......... If the 12v battery goes flat, but still in good shape and not at zero volts, a jump start (not like we're used to) hook up until the dash comes back on line and you get the "ready to drive" message, the traction battery (Hybrid) will recharge the 12v battery using the inverter like normal. You just got to get the 12v system back online. I can almost confirm this but not 100%.

My battery went dead, may be my own fault not sure....... but when I was installing my 40amp C/B I disconnected a large red wire connector that was in the way of tightening the new bolts, and forgot to reconnect it. The next day the battery went dead. Hooked a charger up and about 3-5 minutes later the dash came alive and I left the charger on to fully charge the 12v battery. As I looked for any stray tools under the hood, I noticed the disconnected wire and reconnected etc......... everything seems to work correctly now (200 mile trip since then).
 
sorry to hijack the thread, but you installed a C/B? I wanted to install one - is there a space beside the "view" button and above the USB chargers - or where did you install it?
 
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brianz said:
sorry to hijack the thread, but you installed a C/B? I wanted to install one - is there a space beside the "view" button and above the USB chargers - or where did you install it?
Click to expand...
C/B = Circuit Breaker...... are we talking about the same thing?
 
haha. I thought you meant a Citizens Band radio. LOL. nvm! I need one for the logging roads.
 
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