bclexus

Being new to the GS 450h I have a lot to learn, so I have some questions about the batteries.

The 12 Volt Starter Battery:
Is the 12 volt starter battery special? If so, why is it special? In what way is it special - it's physical size, CCA rating, post orientation, venting?
Can the 12 volt starter battery be load tested the conventional way or does it take special equipment to test its health?
Does the 12 volt starter battery typically have a shorter lifespan? If so, why does it not last as long?
Is the warranty period for the12 volt battery shorter?

The Traction Battery:
Is there a way to self-test the health of the traction battery? How does an owner do that?
When a Lexus dealer tests the health of the traction battery what means (way, method) do they use?
Is sophisticated equipment needed or something an owner can acquire and do?
Does a prolonged period of not driving the vehicle (e.g. 1-2 years) deteriorate the traction battery?

Thank you...

Aegean

See my responses above.

bclexus

Thank you for the answers, Aegean. That was very helpful.

One answer in particular concerns me, however.

Q: Does a prolonged period of not driving the vehicle (e.g. 1-2 years) deteriorate the traction battery?
A: Yes it is very bad. Modules get weak, corrosion on terminals. Hybrids love daily driving with many miles to keep battery happy for many years.

The reason this answer concerns me is because my newly acquired 2018 GS 450h was last driven any extent 12 to 18 months ago. Is there anything you recommend that I should do, or precaution I need to take, to help offset this matter of the car not being driven for a prolonged period of time - other than driving the car?

I'm having the car serviced this week with engine oil & filter change, load testing the 12 volt starter battery, replacing fuel pump (Ref 21LC01 Recall), NAV map update to v.2021, and I have asked for the traction battery to be health tested.

What I do not know is what the Lexus technician will do to health test the traction battery. Do you have any thoughts on that?

Aegean

The traction battery as all batteries slowly discharge. One risk is that the car will not start after so many months and would need to be charged at the dealer with a special hybrid battery charger. Since now you are driving the car this is not a risk.

As we know from our 12v batteries, when a battery is discharged at a very low level the battery will recover. However, if this happens a couple of times the battery might become useless and not hold charge. The same principle applies to the traction battery. Since this is a 2018 battery and this happened once I would not worry much.

As far as corrosion, it is a risk but for a late model battery like this should not be an issue.

At this point you should drive the car normally and enjoy it. I do not think this 12-18 months not in use period would degrade that much a late model battery. The good news is that you have a long warranty 8y/100k for 2018 I believe on hybrid battery.

Aegean

I am pretty sure there is no hybrid battery health test in the service manual. Techstream the official Toyota software is using the term “health test” but it is a scanning of all the computers in the car including the hybrid battery control module for OBD2 codes. This is very different than a battery “state of health” test. You might need to talk to the advisor and ask what specifically they will test on the battery.

bclexus

Thank you again, Aegean.

That was kind of my thoughts too concerning the traction battery, but your input and advice helps ease my mind...

peasodos

iTrader: (1)

Lexus has a weird size 12v battery in the trunk, hard to find aftermarket options.

I ended up taking a hack saw to the battery tray and bottom edge of my new battery to make it fit:
https://www.clublexus.com/forums/gs-...l#post10637314

Other than being AGM with a vent, there is nothing special about the 12V battery, you can basically put anything that fits.

I doubt there is any damage to the hybrid battery after sitting for a year. I doubt it would discharge because the 12V will die long before the hybrid battery even gets a chance to drain. Once the 12V is dead power is completely cut off. The 12V is what powers the car when it's off, cooling systems for hybrid battery, aux, alarms, ect...

Even Tesla's have a 12v battery.

bclexus

Aegean, you are correct. There is no hybrid traction battery health test in the service manual. The only test is the recommendation to self-test the hybrid traction battery by monitoring how many bars the hybrid battery typically has while driving. I'm told the hybrid traction battery will seldom, if ever, display maximum number of bars - but is a good indicator of the general health of the traction battery when almost all the bars are displayed when driving normally.

bclexus

I often get 7/8 bars, with the one bar shy of full quite common. 6/8 bars is very normal. The lowest I've seen is 2 bars, but even that shoots upward very easily with just a little bit of ordinary driving. I rather doubt I'll ever see the full 8/8 bars here in Texas with very few hills to take advantage of...

I'm very happy with all aspects of the car so far. It's a very nice piece of machinery with a lot of features and technology.

I still have a number of things to do in order to get things wrapped-up.
Program garage door openers and gate into rear view mirror.
Add about 40 POIs in the NAV system
Change the lane change from 3 blinks to 5 blinks.
Install the front license plate bracket.
And a few more things...