When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I just got back home from a 6 day vacation to find my 350h battery dead in my freezing garage. Just before the storm Lexus sent out a service to jump the car but we couldn't open the door, and while he knew to access the manual key he didn't know about the latch that ALSO need to be pulled. So he didn't jump start it. Long story short I think I know how to open the door now and then to be able to open the hood. QUESTION: I have a 20 year old battery charger that has clamps and plugs into the wall. If I recall it does a slow or medium charge. Can I use that on the battery under the hood? If so, what settings and what do I need to do to do it safely. Do I charge the battery under the hood or the oen in the trunk? I'd then take it over to Lexus in the next few days when this storm ends.
I would not fart around with this. Just call Lexus roadside assistance, get it boosted properly (watch the ground point connection) and then take it to the dealership. In my experience (now on my 2nd battery in 35 months), your battery is pooched. They will load test and likely instal a new one.
There is only a single 12V battery in the trunk.
But you have a terminal in the engine bay. Check the user manual to find it.
If you just want to jump start, it is easier from the engine bay. If you want to do a full charge with the charger you can just take the battery out of the trunk.
If you are setting the current manually, use 10% of the ampere*hour value: for example 50Ah --> 5A.
On hybrids the 12V battery is only used to start electronics, so it shouldn't take much before you can start the car and let the engine charge the battery.
You have a very good chance that your 12 volt battery is ruined and won't hold a sufficient charge anymore. The dealer should test it and determine if it's still healthy, if not have it replaced under Lexus warranty.
The jump start goes as follows.
You open your door manually with lever and key. Then you pop your hood open. You hook up the booster to the proper terminals. With your booster hocked up, you can now electronically open your trunk door. Then you get to your 12V battery and either connect your jump starter pack to it to start the car. Or you hook up your trickle charger to recharge the battery. Voila
I really hope NHTSA requires a recall on this. A 2025 no matter how long the vacation should not need a new battery, let alone 6 days.
The fact that this appears so commonplace, yet Lexus roadside assistance never knows how to handle it, baffles me.
Sorry for what you went through New2025NX!
Well I and many others will agree with your thoughts too, I don't think a dead battery is gonna be enough to kick off a recall campaign here. Otherwise, four years in, we would have had one already. Other manufacturers have engineered safeguards for this such as Hyundai / Kia. This video shows a '21 Hyundai Sonata hybrid. You'll note you have to get into manual door lock just as Lexus has as well.
Pretty easy!
You'll also come to realize that Hyundai simply solved an issue during the design phase to remedy a what if scenario and no one is saying that it's a flaw or it's a defect! It's simply a thing with smart car technology and they've handled it.
Today Lexus Roadside was able to jump my car. I watched as he explained the ground issue and he clamped it clear across to the other side of the engine. It took two tries but it started. He told me to tell Lexus that the Engine lamp came on and that the battery likely needed replacing. So I drove it Lexus and they had me in and out in about 90 mins, and that included doing the Backup Camera recall. During the repair they sent me a video of the work being done, and that showed that the eye indicator on the battery, and old-schoold indicator, showed that they needed to replace my battery. They also told me that the recall came with a gas fillup-- nice, as I needed almost a full tank!. All my settings stayed intact (carplay, seat location, climate). Lexus treated me well. Fingers crossed this doesn't happen again.
Today Lexus Roadside was able to jump my car. I watched as he explained the ground issue and he clamped it clear across to the other side of the engine. It took two tries but it started. He told me to tell Lexus that the Engine lamp came on and that the battery likely needed replacing. So I drove it Lexus and they had me in and out in about 90 mins, and that included doing the Backup Camera recall. During the repair they sent me a video of the work being done, and that showed that the eye indicator on the battery, and old-schoold indicator, showed that they needed to replace my battery. They also told me that the recall came with a gas fillup-- nice, as I needed almost a full tank!. All my settings stayed intact (carplay, seat location, climate). Lexus treated me well. Fingers crossed this doesn't happen again.
Glad they took care of you, but I highly doubt you'll never see this issue again. I am on my 2nd battery replacement in 35 months and have had a dead battery which needed boosting 5 times. Yes you can call roadside assistance, but with the weather we're having here now, the CAA (equivalent to AAA in the US, which is the service Lexus uses around here) warn that it could take up to 2 days to get a boost. They have limited resources and are focussing on folks in dangerous situations first. So what I suggest is you get your own small booster battery. I chose NOCO, but there are others, discussed on this site. Mine fits in my centre console, so no need to get into the trunk.
Same sentiments as JasDmw. I've installed a trickle charger on my battery in the trunk. I snake the cord out through the plastic battery lid / cover and the floor and out the back hatch. It's the only hope in keeping my 12 volt battery from repeatedly dying on me as I feel I don't drive it enough to keep it fully charged and healthy.
I think we should start referring to these models as 350h- and 450h- as there's not much PLUS in owning them!
Using a Battery Charger
, neat feature!
