ALL POSTS - 12-volt battery replacement

ravisekhar · Apr 8, 2018

Here is my current battery problem.

Car is 5 Yr old
Never Changed the 12 V battery
Clipper Creek 10 AMP Charger

One Morning, The car was trying to charge but i keep hearing click sounds and retries again and again until in the Evening i am back from office.

Car 12V battery is dead as the car no longer turns on.

Jump started using another car, RAV4EV turned on Fine. As soon as i disconnected jumper cable. RAV4EV went dead.

Jump started again and let the other car ON for next 15 mins and jumper cables connected. Assuiming RAV4EV 12 V battery will get charged.

RAV4EV didn't shutdown even after removing the jumper cable.

Tried to charge the car again and it keep making clicking sounds and i disconnected the charging cable.

I turned off the RAV4EV and after 30 Mins RAV4EV doesn't even start again.

Is it 12 V battery problem or something else. Please let me know. Based on your suggestions i will have to decide to take the car to PepBoys or Toyota Dealership .

Advanced thanks for the feedback.

davewill · Apr 9, 2018

It is almost certainly the 12v battery. That the original battery lasted for 5 years is a minor miracle as the RAV is really hard on them. Do NOT reconnect the dead battery to the car any more (and if it's connected, disconnect it). Low voltage situations have been known to cause lockups that require dealer intervention to correct. Get a new battery and install it ASAP. Read further up the thread for specific battery recommendations.

smkettner · Apr 9, 2018

Need to measure the actual 12v battery voltage after you remove the cables. Voltage should rise above 14 volts if the DC/DC converter is working.
Regardless you needed a new 12v battery a year ago.

TonyWilliams · Apr 11, 2018

Yet another GREAT example of why you don’t wait to change the 12volt battery. If you have the original 12 volt battery, CHANGE IT NOW.

Good luck with all the issues caused by not proactively replacing the 12volt battery.

ravisekhar said:
Here is my current battery problem.

Car is 5 Yr old
Never Changed the 12 V battery
Clipper Creek 10 AMP Charger

One Morning, The car was trying to charge but i keep hearing click sounds and retries again and again until in the Evening i am back from office.

Car 12V battery is dead as the car no longer turns on.

Jump started using another car, RAV4EV turned on Fine. As soon as i disconnected jumper cable. RAV4EV went dead.

Jump started again and let the other car ON for next 15 mins and jumper cables connected. Assuiming RAV4EV 12 V battery will get charged.

RAV4EV didn't shutdown even after removing the jumper cable.

Tried to charge the car again and it keep making clicking sounds and i disconnected the charging cable.

I turned off the RAV4EV and after 30 Mins RAV4EV doesn't even start again.

Is it 12 V battery problem or something else. Please let me know. Based on your suggestions i will have to decide to take the car to PepBoys or Toyota Dealership .

Advanced thanks for the feedback.

rickrides · May 26, 2018

I did what Tony said and replaced my original battery, that was almost 4 years old, with the Bosch AGM in February. I've been getting air bag error messages for the last few days so I checked the voltage when I got home and it read 9.6 volts. I charged it to 14.6 and disconnected the charger and the voltage started dropping. I disconnected the neg terminal and the battery is holding at 12.75v. I get a pretty good spark when I touch the neg cable to the neg battery terminal. There seems to be a load discharging the battery...Any suggestions? The car can sit unused for up to 3 days at a time.

smkettner · May 26, 2018

rickrides said:
I did what Tony said and replaced my original battery, that was almost 4 years old, with the Bosch AGM in February. I've been getting air bag error messages for the last few days so I checked the voltage when I got home and it read 9.6 volts. I charged it to 14.6 and disconnected the charger and the voltage started dropping. I disconnected the neg terminal and the battery is holding at 12.75v. I get a pretty good spark when I touch the neg cable to the neg battery terminal. There seems to be a load discharging the battery...Any suggestions? The car can sit unused for up to 3 days at a time.

Mine did this. Was about 2 amp load that never shut off. Turned out to be the Gateway computer. You need to keep it on a charger or start pulling 12v fuses until the drain stops. Get it into the dealer asap.

BTW Carson Toyota would not work on my car with the larger Bosch battery. They told me it was draining because it was too large. (WTFH?) Installed a Toyota battery (over $200 my cost) and it died 2 days later. Towed to Irvine Toyota to get an actual technician to look at it. Three tows later Tesla decided it was the computer.

http://www.myrav4ev.com/forum/viewtopic.php?f=7&t=1775&hilit=drain

rickrides · Jul 3, 2018

rickrides said:
I did what Tony said and replaced my original battery, that was almost 4 years old, with the Bosch AGM in February. I've been getting air bag error messages for the last few days so I checked the voltage when I got home and it read 9.6 volts. I charged it to 14.6 and disconnected the charger and the voltage started dropping. I disconnected the neg terminal and the battery is holding at 12.75v. I get a pretty good spark when I touch the neg cable to the neg battery terminal. There seems to be a load discharging the battery...Any suggestions? The car can sit unused for up to 3 days at a time.

I replaced my Bosch AGM today with another one under warranty. It tested bad at Pep Boys and they gave me a new one. It had almost no capacity. For being such a great battery, it didn't last very long.

I will continue to monitor the new battery to see if there is a phantom load draining it.

Incredulocious · Sep 18, 2019

rickrides said:
I replaced my Bosch AGM today with another one under warranty. It tested bad at Pep Boys and they gave me a new one. It had almost no capacity. For being such a great battery, it didn't last very long.

I will continue to monitor the new battery to see if there is a phantom load draining it.

I just replaced my Bosch AGM under warranty as well. I started seeing the usual early warning signs of low 12V battery and its inability to hold a charge even though I’ve been keeping it on a trickle charger. However, my guess was that this was fallout from one year ago when it was accidentally left not connected to the trickle charger for several months while I was out of town and the battery was drained. I managed to reharge the battery but I had to pay a lot to the dealer to get them to reset the error codes. The battery held up for another year at least.

When I went to the original Pep Boys yesterday to exchange it under warranty, they were out of the Bosch AGM and gave me a matching Champion AGM – same four year warranty.

Now I see that thread linked above about the “gateway computer” pulling 2 amps while the car is off and needing replacement for some folks... I guess I’ll go check for that now.

Weekdayskier · Sep 19, 2019

My 3 year old bosch agm battery vaporized a couple of months ago.

I was on a 200 mile trip, using Chademo chargers

Noticed a smell while charging, steam venting out of the battery while charging after 100 miles.

I did let the car rest, battery cool before resuming the trip.

On the return drive, I would notice the smell whenever I was stuck in traffic, assume it was continuing to vent.

Pep boys tested the battery. It had 1 CCA on their test.

They replaced the battery under warranty, but informed me that I needed to have the charging system checked. The suggestion is the battery failure was caused by overcharging.

It's been working fine since, including a few 90 mile trips.

Reading on AGM batteries, I'm curious if there is a Battery Sensor Module than needs to be programmed for AGM.

https://www.knowyourparts.com/technical-resources/blog/three-misconceptions-agm-batteries/

hokiematt · Sep 20, 2019

Weekdayskier said:
They replaced the battery under warranty, but informed me that I needed to have the charging system checked. The suggestion is the battery failure was caused by overcharging.

It's been working fine since, including a few 90 mile trips.

Reading on AGM batteries, I'm curious if there is a Battery Sensor Module than needs to be programmed for AGM.

https://www.knowyourparts.com/technical-resources/blog/three-misconceptions-agm-batteries/

There is no battery sensor module. The Tesla gateway commands the voltage setpoint for the DC-DC converter; at 70 deg F ambient it's around 14.5 V, and will increase as temperature decreases. The DC-DC is only active when the vehicle is in READY mode.

Grab yourself something like one of these: https://www.amazon.com/gp/product/B01N00I4TM/ It's a quick and easy way to keep an eye on the 12V system health, at least within a tenth or two of a volt. If you see voltages much above 15V you may be damaging your battery, and voltages much below 13V would indicate the DC-DC is not working.

ferenc · Oct 8, 2019

so, i have two simple questions about the 12v battery (which i replaced recently). what does it do and how does it get recharged?
tx,
ferenc

davewill · Oct 9, 2019

ferenc said:
so, i have two simple questions about the 12v battery (which i replaced recently). what does it do and how does it get recharged?
tx,
ferenc

It provides 12v power for all of the systems in the car...computers, headlights, navigation, seat heaters, etc... It is charged by a DC to DC converter that operates when the traction battery is active. This happens when the car is "Ready" and during charging, I believe. Only a few things run directly off the traction battery: The electric motor, the heating element for the cabin heater, and maybe the AC.

miimura · Oct 9, 2019

davewill said:
ferenc said:

so, i have two simple questions about the 12v battery (which i replaced recently). what does it do and how does it get recharged?
tx,
ferenc

Click to expand...

It provides 12v power for all of the systems in the car...computers, headlights, navigation, seat heaters, etc... It is charged by a DC to DC converter that operates when the traction battery is active. This happens when the car is "Ready" and during charging, I believe. Only a few things run directly off the traction battery: The electric motor, the heating element for the cabin heater, and maybe the AC.

There are separate HVDC PTC heaters for the cabin and the battery pack. The A/C compressor also runs on high voltage as well as the electric power steering.

ferenc · Oct 10, 2019

Thanks, so theoretically, one _could_ use the EV for limited current emergency off-grid power, through a 12v inverter ...
I wonder what the rated charging current and voltage to the 12V battery are, or if one would have to charge the battery, disconnect/turn off the car and then hook it up to the inverter?
Ferenc, who had initially hoped to do so directly with the large battery pack ...

miimura · Oct 10, 2019

ferenc said:
Thanks, so theoretically, one _could_ use the EV for limited current emergency off-grid power, through a 12v inverter ...
I wonder what the rated charging current and voltage to the 12V battery are, or if one would have to charge the battery, disconnect/turn off the car and then hook it up to the inverter?
Ferenc, who had initially hoped to do so directly with the large battery pack ...

It is pretty easy to get 1,000W out from the 12V system. Just make sure the car is on and READY so that the DC-DC will maintain the 12V from the traction battery. Also, don't use an AGM battery if you will leave the car parked for extended periods in READY like this. They will overheat and vent toxic fumes. I have a disconnect on my AGM and I connect a LiFePO4 12V in parallel.

This is my RAV4 EV set up for 12V power export. The green knob on the negative terminal disconnects the Bosch battery.

ferenc · Oct 15, 2019

miimura said:
ferenc said:

Thanks, so theoretically, one _could_ use the EV for limited current emergency off-grid power, through a 12v inverter ...
I wonder what the rated charging current and voltage to the 12V battery are, or if one would have to charge the battery, disconnect/turn off the car and then hook it up to the inverter?
Ferenc, who had initially hoped to do so directly with the large battery pack ...

Click to expand...

It is pretty easy to get 1,000W out from the 12V system. Just make sure the car is on and READY so that the DC-DC will maintain the 12V from the traction battery. Also, don't use an AGM battery if you will leave the car parked for extended periods in READY like this. They will overheat and vent toxic fumes. I have a disconnect on my AGM and I connect a LiFePO4 12V in parallel.

This is my RAV4 EV set up for 12V power export. The green knob on the negative terminal disconnects the Bosch battery.
...

This looks great! I did so, rather ad hoc during our recent power outage, loading the system up to 850W. I don't understand what the green knob is connected to - some sort of high current switch? Is your system turn-key or custom? I love the monitoring meter, as well as the quality of the workmanship. I resorted to using large clamps onto terminals, but would prefer to have a setup similar to yours,
Ferenc

miimura · Oct 15, 2019

ferenc said:
This looks great! I did so, rather ad hoc during our recent power outage, loading the system up to 850W. I don't understand what the green knob is connected to - some sort of high current switch? Is your system turn-key or custom? I love the monitoring meter, as well as the quality of the workmanship. I resorted to using large clamps onto terminals, but would prefer to have a setup similar to yours,
Ferenc

The green knob is a disconnect. It allows you to easily reboot the car. In my case, I also cannot leave the car in READY for extended periods of time because the Bosch AGM battery overheats. I have a LiFePO4 battery that I temporarily connect when I want to leave it on for long periods. Just opening that green knob takes the Bosch battery out of the circuit.

ferenc · Oct 15, 2019

so the green knob comes with the setup, or is the setup custom made?
is it a high current switch or something mechanical/home made?

i'd be interested in buying/making something similar - how did you accomplish your setup?
thanks.

miimura · Oct 16, 2019

ferenc said:
so the green knob comes with the setup, or is the setup custom made?
is it a high current switch or something mechanical/home made?

i'd be interested in buying/making something similar - how did you accomplish your setup?
thanks.

The green knob thingy is a standard automotive battery disconnect accessory. You can find it at most auto parts stores. I bought this one: Harbor Freight - Battery Disconnect Switch

The rest of the non-OEM stuff you can see in the picture is either part of the JdeMO installation, or added by me for the 12V power export. Here's the parts list for the power export:

Amazon - 100 amp breaker
Amazon - 100 amp DC current shunt meter
Amazon - Anderson type 2-4ga 175 Amp Connector
Amazon - 4 gauge wire and crimp lugs
Amazon - 4 Position waterproof connectors

Lastly, I designed and 3D printed the bracket to hold the shunt and the breaker. It uses existing M6 threaded holes in the engine compartment.

TonyWilliams · Oct 17, 2019

You can use a simple M8 wing nut. Every JdeMO™ installation includes this. We would be happy to send you one with a flat washer.

https://shop.quickchargepower.com/12-Volt-Battery-Quick-Disconnect-for-Toyota-RAV4-EV-RAV412VDISCONNECT.htm

The Bosch AGM battery has been a disappointment over the years. Yes, you want a Group 24F or bigger battery, and you want the largest amp hour rating (not cranking amps... we don’t need that). It also should be a deep cycle type battery. AGM would be a plus.

But, the Bosch batteries fail too often, and overheat too much.

ALL POSTS - 12-volt battery replacement

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