RAV 4 Hybrid - battery dead flat after garaging (2 months)

[2ToTango]

Hello,  I gargaed my hybrid last year for 2 months to find it totally dead on my return. I tried a jump start but it did not work. RAC could not start it. In the end I had to tralier the car to the Toyota garage (at great cost). It turns out a trickle charge was sufficent to recharge the 12v battery and start the car. This year is garaged the car again for 2 months but after pulling out a fuse that a you tuber recommneded to avoid this problem. But that did not work - I still have a dead flat battery.  I am confused with my interent research. Some say a tickle charge is not good for the 12v battery and some say you should put the 12v battery on trickle charge if its left standing for more than 1 month. SUrely I am not the only person with RAV4 hybrid who goes overseas every year for a couple months. What is the solution to thsi problem other having someone come in and drive it around the block every week!  Any insights and guidance you can provide would be greatly appreciated.

Edited August 15, 2023 by 2ToTango
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[CONROD]

You need to get yourself one of these, I have one mounted next to my weekend driver, works perfect.

If you read thru it can be left switch on/ connected indefinitely

12V 5-Stage Car & Motorbike Maintenance Charger (0.8A / 3.8A, IP65 rated) | Jaycar Electronics

[2ToTango]

Thanks Conrod. So you use this with your RAV 4? I am asking becuase I read some threads that say trickle charge is not good for the 12v battery. BUT I know my toyota service provider did recharge last time using a trickle charge overnight. I am guessing the issue to ensuring that you do not overcharge. A possibility if it on for 2 months. But a smart trickle charge fixes this issue. I see JarCar has discontinued your recommendation - but replaced with this one - https://www.jaycar.com.au/6-12vdc-3-8a-8-step-intelligent-lead-acid-and-lithium-battery-charger/p/MB3904?utm_campaign=redirect&utm_source=MB3904r&utm_medium=web  It seems to be smart (features overload, short circuit, reverse polarity, safety timer and wrong battery protection). Thanks for your help.

 

[Tony Prodigy]

7 hours ago, 2ToTango said:

I read some threads that say trickle charge is not good for the 12v battery.

Absolute B.S. In fact, it is quite the opposite. Without a trickle charger, most modern cars will have flat batteries everywhere due to their parasitic drain the onboard systems require when the car is locked.

I would never be without one. I have 6 C-Tek trickle chargers for various vehicles I own. Has never let me down. Look into the C-Tek range if you have no joy with that Jaycar one which conrod linked. They seem to be out of stock for the moment, but if you can get one, it's good value.

[CONROD]

Totally agree with Tony, BS whoever wrote that doesn't understand, the best way to kill a battery is let it completely discharge, and if you can't trickle charge a battery, why did Toyota do it ??? .

The one I posted is the one I use as I needed it to maintain an 850CCA 95Ah AGM battery and I can't fault it., had it for years now, noticed the updated version is suitable for Lithium batteries.

I affixed the supplied harness to the battery terminals, so all I have to do is plug it in to the charger lead and walk away, knowing the charger will go through whatever steps are required and once fully charged, settle into trickle mode.

C-Tek is also a good brand as Tony P uses

Supercheap and Autobarn have them, but like everything you get what you pay for

Edited August 18, 2023 by CONROD

[2ToTango]

thanks for the comment and confidence. I brought it on line. I am still overseas but sent my son out to take the car for a drive. He reported it was already flat, so I'll need the trickle when I get home. Cheers.

[Tony Prodigy]

7 hours ago, 2ToTango said:

thanks for the comment and confidence. I brought it on line.

Happy to help. Which one did you buy ?

The C-Tek has a recondition feature on models MXS 5.0 and up. You use this feature to desulphate the battery first before you attempt to charge it. This will help make the battery more healthy and take a better charge to handle the cranking amps. When a battery becomes sulphated it is practically dead, but you can bring it back if you have the correct charger. The cheaper versions usually don't have this and I'm not sure if the Jaycar one has it either.

See how you go. 

Here's some good reading material 

https://www.power-sonic.com/blog/what-is-a-sulfated-battery-and-how-do-you-prevent-it/

https://www.ctek.com/uk/news-archive/looking-after-your-car-battery-as-you-come-out-of-quarantine

[CONROD]

Yeah the one I got has it👌

[2ToTango]

I am thankful and grateful for these replies. I got a Powertech 6/12VDC 3.8A 8 Step intelligent Lead acid and Lithium Battery Charger (https://www.jaycar.com.au/6-12vdc-4a-8-step-bluetooth-intelligent-lead-acid-and-lithium-battery-charger/p/MB3906) posted to me from Jaycar (ordered before your recommendation Tony). It was waiting for me on the doorstep when I returned from my overseas trip. Sure enough the car battery was dead flat. My booster did not have a hope. I took the 12v battery out of the boot and connected the trickle charger. It was a bit too intelligent (or maybe not intelligent enough) because it immediatly set itself to charging a 6v battery. Instructions say to select your mode. I found that the system did not respond to me pressing the mode button, although there was a moment when the recovery mode was selected it would swtich back to the 6v. I tried pressing the mode numerous times and eventualy I was able to select and hold the recovery mode. After 6 hours I was already about 50% "full". I left on all night the in the morning I had a fully charged green light. The car started as normal after reinstalling the battery. Why does the manual not tell you to use a trickle charge when storing the car? Thanks guys you saved me heaps of money for a tow truck. 

[Tony Prodigy]

15 hours ago, 2ToTango said:

I am thankful and grateful for these replies.

Our pleasure. Always happy to help out another fellow motorist.

16 hours ago, 2ToTango said:

I got a Powertech 6/12VDC 3.8A 8 Step intelligent Lead acid and Lithium Battery Charger (https://www.jaycar.com.au/6-12vdc-4a-8-step-bluetooth-intelligent-lead-acid-and-lithium-battery-charger/p/MB3906) posted to me from Jaycar (ordered before your recommendation Tony).

All good man. I try to recommend only what I buy, use and trust. Like I mentioned, I have 6 C-Teks and all have been excellent and serve an important function in maintaining all my batteries, be they in the car or sitting in my garage for stored vehicles.
I always keep an eye out for sales, especially when Amazon have those sales days where they slash prices by more than 50%. I jump on the items I need during this time. I recently got myself the C-Tek MXS-10 for under $200, normally retails for between $350 and $400. 

16 hours ago, 2ToTango said:

Why does the manual not tell you to use a trickle charge when storing the car?

It would be good if they did, but the general consensus is that they assume we know this. I learned the hard way, same as you and have made certain never to fall back into that position again. My first C-Tek was an MXS 3.8 for my garage queen M3. 
All modern cars with complex electrical systems will have a parasitic drain even when the car is off and locked, so if you leave it stored for a prolonged period, it will drain the battery.

I have permanently connected the eyelet adapter to the battery terminals (battery is in the boot), and just run the C-Tek extension cable to the charger. The cable is thin enough for me to even shut the boot lid and lock the car while it trickles the battery. No need to remove the battery.

They call them "comfort connectors"

 

[Jhono]

Hi guys,

I'm actually very lucky I found this thread. Got a question I have 2021 Toyota Rav4 Hybrid and looks like the battery is drained flat (hope so). Wife wanted to go the shop and she was calling me she cannot open the car so I had to manually open it, the car is not responding to anything. So I believe its the battery. My question is any of these battery chargers would work? 

https://www.jaycar.com.au/6-12vdc-3-8a-8-step-intelligent-lead-acid-and-lithium-battery-charger/p/MB3904?utm_campaign=redirect&utm_source=MB3904r&utm_medium=web
https://www.jaycar.com.au/6-12vdc-4a-8-step-bluetooth-intelligent-lead-acid-and-lithium-battery-charger/p/MB3906

And also do I need to remove the battery or I can charge it from the front as I cannot open the back. I know I can manually open it just need to get to the back and use a screw driver which trying to avoid if not needed.

Thanks.