iousin009

This is exactly what I was experiencing. If left for fourth day going completely flat.

Yea it was weird both my old and new replaced battery gave same readings and with two different meters. If you scan through this thread from the beginning, it should have more numbers. Not sure if any other members have recorded their IS 300h battery voltage.

My readings indicate that this battery voltage is different than the standard AGM voltage chart. At 12.55 volts my meter indicated 91% charged, so think a 100% charge will be around 12.65

You guys reckon I still have some draw issues with my car? I can go to the dealer for further investigations. He'll charge me for investigation. I'll do more tests when I'm not driving, right now weather is getting good so will be doing long drives every weekend. I'll do tests with 10/13/16 days parked and will report back here. I have another old car so can manage without driving this one.

After 7 days parked my battery was showing 60% charged. Just summarising my thread. My 2019 IS 300h came fitted with the 49AH panasonic battery. I was driving quite less (maybe once a week 10-15 minutes) and got flattened once. Since then even though driving at least one hour a week, was still getting flat if being left for 1 week. This got worse over time and my battery got Flat 5 times, think it lost around 50% of it's capacity around this time. So was getting flat every fourth day. Have been to dealer twice, both the time they tested and just sent me back saying battery is all good! Then with the help of these forums have done some testing and then went to the dealer again with some numbers at hand, he was finally convinced to replace the battery. By this time batteries were out of stock. I was given an option to replace at kwik-fit or Halfords. Halfords said they will not touch the Lexus hybrids battery. Kwik-fit were going to put the battery whose width is 172mm, not sure how as existing battery width is 125mm! I waited for battery to be in stock with the dealer. Was putting noco to work every fourth day. After replacing the battery the last two cmments above are the results. My major finding is (as highlighed in the beginning of the thread by some members) just never get the battery to go flat, once it's flat it'll end up with all sorts of troubles and have to be replaced. Thanks to all the members without their help this wouldn't have been possible.

The battery and electrics might both be different. Was the 2014 had the same 45/49AH battery?

Hi Members, I'm back again. Got battery replaced by the dealer on Monday 17th. The battery model is same as mentioned here It's a Toyota 45AH, 325A. Put my noco to work on the same night for 24 hours. Removed it on Tuesday night, then on Wednesday morning did a test. Lexus computer showed 12.3 volts and my battery tester showed 12.54 volts ! As it's a new battery thought I'll give it another go with a proper tester as my old tester doesn't have any option of selecting battery type and input CCA. So immediately ordered Topdon On Thursday drove the car continously for 2 hours. Parked around 9PM. Friday around 9PM tested with topdon. Have selected "AGM Flat plate" and input CCA 325 (as on battery written 325A). It showed health 100% with 91% charged. Waited for another two days and tested today(Sunday) around 9PM. 78% charged. Think with this rate in 8-9 days battery will go down to 50% charged. Will test again after 3 days and then will put noco to work if not driving. At least the new battery is not getting flat every 4 days. Still have doubts about the 5-6% daily drain. Does others have observed similar drain with their IS 300h batteries (45AH)? I'm happy to put noco to work for a day every week, think will have trouble going on a two week holiday, will need to disconnect the battery in such situations. Thanks for all the support.

Hi, The kwik-fit battery which on their website show compatible had width of 174mm, my existing battery width is 125mm, I'm not sure how they were going to fit 170mm+ width battery in here, so have hold on. Just waiting for the battery to become available in a Lexus dealership and then will make a booking. You need to do some tests and approach the dealer with the numbers then only the dealer will be convinced to replace it, I had to do the same then the dealer agreed for replacement. As my car is less than 2 years old, I'm reluctant to fit any battery outside lexus dealership. If you'd like to go for it then bosch recommendation from David should be able to fit, please check the dimensions though.

Thanks, makes sense. The position of the terminal also matters not just the size of the battery.

Thanks William and Herbie, I'll go for the Kwik-fit battery then, start/stop might be an overkill. Is this the Varta battery you've searched for? I'll also check with Kwik-fit if they are happy to fit a battery bought from outside. Cheers.

Hi Members, Quick update. Apparently batteries are out of stock with an unknown ETA, have rang 6 different Lexus dealerships, they all say the same thing. My Dealer gave me an option to get a battery replaced (without invalidating the warranty) with either Halfords or Kwik-Fit. Have approached Halfords they are reluctant to touch as it's a Lexus. They once did it and the car didn't start and have to be towed to Lexus service centre. Kwik-fit are happy to put in the following battery. Which looks to be not an AGM https://www.kwik-fit.com/batteries/search/details/030 Having the feedback of Halfords I'm having second thoughts. What I came to understand from reading on these forums that, this is just a starter battery whose function is to only boot the lexus computer and put the car in ready state. There are some peeps who have successfully put various batteries including AGM and Mobility scooter batteries as well. So any battery should be good to fit? Have found a close match of an AGM battery as per my existing battery dimensions is: https://www.halfords.com/motoring/batteries/car-batteries/halfords--096agm-start%2Fstop-agm-12v-car-battery-5-year-guarantee-548638.html I could just ask Halfords to fit the above and I'm responsible if something happens. Any thoughts/suggestions is much appreciated Thanks

Cheers for all the draw test videos, I must admit it's still out of my expertise and the car being less than 2 years old, reluctant to play with fuses, I might damage something 😞. Also my car being parked on road, it'll be difficult to try out all these ideas.

After speaking with the dealer with all the numbers, they agreed to replace the battery. Hopefully mine also turn out to be battery fault only. Cheers.

So today I connected noco for about 12 hours. It went into maintenance mode soon after 3 hours. Then recordings are: Tester - 12.48 Vehicle Signal - 12.0 It's like the battery has capped itself at 50% mark and doesn't charge beyond this. With this information I'll get in touch with the dealer, I hope they will accept that some voodoo happened to the battery. Will try the repair mode after getting in touch with them. Thanks for help everyone.

Cheers, Also on the noco manual it's mentioned "this node is for lead-acid batteries only" I gues AGM is also a type of lead-acid battery? Will the doors lock after I disconnect the battery, keyless lock will work? Guess I can always lock with the key.