I would definitely keep voltage on the system while swapping out the battery. If you don't know how, or don't have the tools to keep voltage on the system, I would recommend having the battery replaced by either Lexus or NTB (National Tire & Battery) or some other equally qualified shop. The price for a replacement battery from Lexus is very fair. Some people have had quirky things (MAF needed cleaning due to rough engine, emergency brake lock, etc.) happen when not maintaining voltage on the system, which cost some of them a towing charge, time and money to get sorted out.

 

Great, thank you! Yeah, I'm thinking the dealer route will be the way to go. I have a battery tender but not sure that does the trick with keeping voltage present, and I want to avoid any such anomalies. Appreciate it!

 

I have disconnected mine (2015 f sport AWD) three times now (long story which I won't bore you all with) and not had anything like that happen, at 55K. IMHO the "worst" thing that happens is there's about a 95% chance the car will stall the first time you go to start it, then it will start properly on the second start. Other than that it's mostly "much ado about nothing". Most of these cars aren't like a BMW or an MB where they will totally lose their **** if you unplug the battery. Then again different model years might be different, and given the presence of a good shop, your advice is pretty sound, given the opportunity to replace with negligible increase in costs. The problem is the pep boys I bought my battery from is dodgy as hell, and I didn't want them to do it. Next time around I'll just strap a low current 12vdc supply to the wires before taking it off.

ETA: Another piece of advice for DIY types... if you buy a new battery charge that ***** up before installing- a lot of those things sit on the shelf for many months at a time and not fully charged. No use beating your alternator up over nothing if you can top it off before installing.

-Mike

 

I at least partially disagree, at least in temperate climates. My mom's 2013 ES350 battery is still plenty strong given its age, but she doesn't drive that car much (it has like 30K on it tops) and it's rarely if ever beat up under duress.... little to no night driving, almost no starts when its brutally cold, etc. The battery is never really stressed.

All other things aside, people that don't drive will replace their batteries less often than people that do. I can never get more than 3 or 4 years out of a battery. I know other guys that do **** for miles and never replace the battery before they dump the car/truck it was in! Friend of mine just traded in his 04 Tacoma not long ago and it still had the original battery in it, but that truck had crap for miles on it. Was used every day almost but his commute is about a 1/4 mile. Truck spent more time idling than driving! (because of his remote start).

ETA: I agree that, if you live in hell on earth, time will just kill the damned things. Friends I have down south never get more than 3-4 yrs regardless of habits, the heat just beats the **** out of them.

-Mike

 

My 2013 450h battery finally died. There is no warning for this battery it works great until one day you can't open the door with fob.

The original battery was a Panasonic
Group: D26
20HR 57Ah
CCA 450A
10" x 6.5" x 8"
37.2 lb
Cost $355 plus tax at Lexus Dealer

I'm replacing it with:

DieHard 50748 Group Advanced Gold AGM Battery

Group: 48
20HR 70Ah
CCA 760A
11 x 6.9 x 7.5
47.5 lb
Cost $193 plus tax, 2 day shipping. I work from home so don't mind waiting for a battery.

The new battery is physically slightly larger, bigger capacity, and 10lb heavier, so should be more than enough.
It also has the vent hole in the same location as oem. Important to connect the stock vent line to the battery since it's located in the trunk.

 

Yeah I usually have to replace batteries around the 3-4 year mark down here where its really hot. No way around it. It's just too hot down here where the heat just destroys these batteries. Some of my cars that sit for a long time and go unused that eventually get deeply discharged damages the batteries even quicker. These lead acid batteries like to be kept fully charged and will deteriorate quicker in cars seldomly used and not on a battery maintainer.

 

You should get a Battery Tender to charge you car while it is sitting. I do it for all my cars, batteries always topped off and ready to crank every time. Helps keep the battery healthy for longer too.

 

Yeah its definitely up there on my list of to-do. I do worry about lightening strikes and possibly a surge going into the car electronics, I am pretty sure this is an unnecessary concern and could potentially be alleviated with surge protectors and what not but yeah that always scares me. I live in an area that rains a lot.

 

I’ll likely need to replace the 12V in my GS450h too soon but it’s not something that will strand me because I have a portable lithium ion jumpstarter in my trunk.

 

Just curious why you didn't go with the DieHard Group 35 (to match the original).

I'm still rocking the original battery in my 2013, but I'm sure my time could come at any time.

~ Im2bz2p345

 

The original has a 57ah capacity. The Diehard Group 35 has a 50 ah capacity, group 34r has a 55 ah capacity, and the group 48 has a 70 ah capacity.
I wanted a battery with at least the factory capacity. It will be sort of an upgrade in that it has more capacity and it was only a few $ difference. In the 450h battery thread the guys from Europe posed about a Toyota battery that was 65aH capacity, only $120, and vented. This would have been perfect for my car, but I searched and searches could not find the equivalent battery for the USA.

The Diehards had better rating on Amazon than the Optima Yellow top, also several guys in the 3gs forum reported issuies with the yellow tops pre-maturely failing in the 450h.

I took some measurements and found out the battery tray has a length of 10", the Diehards are slightly bigger than this. Lexus purposely made a weird battery size to make you buy the original one.

So I have to hack saw the side of the battery tray. I first tried drilling out the pinch welds, but could not pull it apart, so hack saw is the only solution. I plan on resparing the exposed metal to prevent any potential rust. Lexus used a strong metal for the tray too.
Lol a lot of work to change a battery, but I like the challenge. I'll post pics when I finish the tray mod tomorrow.



There is a metal bar the bolts down from the top that hold the battery in place, so it's not going anywhere.

The original battery on my car lasted 97k miles 6-7 years assuming it was sold/made in 2012. That's one hell of a battery, but I didn't want to pay $400 for a battery.

 

Battery holder successfully modified, waiting for new battery that's coming in tomorrow.

 

2014 GS350, 14250 total miles. On my third battery. I’m retired and drive from my home on the first fairway to the clubhouse.

 

Couple weeks ago I changed the battery in my father-in-laws gs350. 2013 with 20k miles and original battery. Bubbled up a little bit. But I was told the alternator is bad. Any one have experience. Held voltage at 13.42v constant and nothing lower. Didnt change the alternator since in my opinion it’s perfectly fine.

 

Amazon failing me lol, Battery was supposed to deliver tomorrow now tracking says Monday. I did a live chat with UPS and they said Amazon tendered it past the cutoff to deliver tomorrow. Went to Amazon live chat asked for a supervisor told them this will cost me $30-50 in Uber fees. They issued me a $30 credit, but don't really need my car this weekend, just use the fiancée's. Well at least I get $30 off the battery.