12V Battery Health - Long Journey

12V Battery Health - Long Journey

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Discussion

JD82

Original Poster:

376 posts

150 months

Hi all,

I'm taking my Lexus RX450h to the South of France in August, and it occured to me the 12V battery was replaced in March 2020 by RAC. I believe they fitted a "more powerful one" as the Lexus spec one was hard to come by in Covid.

Question is - and it's not been giving me any trouble - whether at 5 years old I need to check the health of that battery before I go or is 5 years well within it's lifespan? Grateful for any advice. And can I do it myself easily if I biuy a cheap multimeter or suchlike?

Thanks

Krikkit

27,446 posts

196 months

No, just carry on.

Scrump

23,429 posts

173 months

If you are not having battery issues then I would see no need to worry about it for an upcoming long journey. Long motorway stretches with the alternator running are not putting the battery under stress (as opposed to lots of short journeys in the winter).

Multimeter is useful but a proper battery tester is needed to know the state of health of the battery. Some places will do a free battery heath check (e.g, Halfords).

5 years is around the time when batteries may start failing in my experience, but I wouldn’t worry about it for your forthcoming trip.

JD82

Original Poster:

376 posts

150 months

Thanks - that's really helpful.

JD82

Original Poster:

376 posts

150 months

Scrump said:
If you are not having battery issues then I would see no need to worry about it for an upcoming long journey. Long motorway stretches with the alternator running are not putting the battery under stress (as opposed to lots of short journeys in the winter).

Multimeter is useful but a proper battery tester is needed to know the state of health of the battery. Some places will do a free battery heath check (e.g, Halfords).

5 years is around the time when batteries may start failing in my experience, but I wouldn t worry about it for your forthcoming trip.
I'd assume Halford would just tell me it's time to replace anyway!! But a good shout too.

pistonheadforum

1,188 posts

136 months

If you are nervous just get a emergency jump start battery kit (can probably buy it there if needed).

From memory the 12v battery in Lexus us just used for the electronics and to control the relay with most of the heavy lifting being done by the traction battery.

donkmeister

10,344 posts

115 months

Echo the above for "don't worry about it".

12V batteries USUALLY degrade somewhat gracefully, i.e. you get signs that they are on the way out before they go. However, what is always the case is that they work better when warm than when cold. So, a battery that seems fine now will probably be fine in the warmer climate of southern France.

The other good thing is that you can get a 12V battery easily, it requires minimal tools to replace and it's easy to get to in an RX450h (under the boot floor, IMO the best place for a battery). So if you were really unlucky and your 12V battery suddenly shat itself abroad... you can just buy and fit another.

ETA even if you can find the right size you can use a smaller one as an emergency measure. When I bought my LS460 someone had fitted what I suspect was a Yaris battery. Toyota branded, but rattling around in the battery tray and they'd discarded the battery tie-down. First job was to sort that!!!

Edited by donkmeister on Monday 21st July 10:52

JD82

Original Poster:

376 posts

150 months

donkmeister said:
Echo the above for "don't worry about it".

12V batteries USUALLY degrade somewhat gracefully, i.e. you get signs that they are on the way out before they go. However, what is always the case is that they work better when warm than when cold. So, a battery that seems fine now will probably be fine in the warmer climate of southern France.

The other good thing is that you can get a 12V battery easily, it requires minimal tools to replace and it's easy to get to in an RX450h (under the boot floor, IMO the best place for a battery). So if you were really unlucky and your 12V battery suddenly shat itself abroad... you can just buy and fit another.

ETA even if you can find the right size you can use a smaller one as an emergency measure. When I bought my LS460 someone had fitted what I suspect was a Yaris battery. Toyota branded, but rattling around in the battery tray and they'd discarded the battery tie-down. First job was to sort that!!!

Edited by donkmeister on Monday 21st July 10:52
Thanks - makes sense. The current battery the RAC fitted doesn't actually fill the tray properly - I remember they had to sit it up on blocks as the OEM one is an unusual shape apparently.

RE you Yaris battery, I remember years back buying a used Focus and finding the battery was tiny as well! I think suited more to a KA....