Since I bought my 450H+ 1 year and a half ago, I had the 12 v battery dead several times. Each time, connecting it to a smart charger restored it to full.

A week ago the battery got dead after only 15 minutes programming the settings in the car without the engine running (on ACC mode).

I tried using a trickle charger (Noco Genius2D – 2A). I left it on for 2 full days. The LED kept blinking red. It never started to blink green as it is supposed to do when it is over 75% of the process and of course never full green (indicating process is finished). I am wondering if the Genius2D is compatible with this battery, even though it says it is OK for AGM batteries...

I checked the voltage and found it to be at 11.7V (meter connected to the cigarette lighter/power outlet in the front). When I start the car on EV (I drive the car 99% of the time on EV mode, city driving) it shows 14.4V for a few minutes then goes to 12.8V for most of the trip. Occasionally it jumps back to 14.4V for a short time.

I decided to get the battery checked at Lexus. The day before I connected the battery to my charger and after 6 hours it showed as full. 2 hours before going to the shop I plugged it again to top it up so I would not have to wait too long for the battery to fully charge for the test. Once connected, the charger showed “Battery Low” even though it was “Full” the night before and no one used the car...

The dealership tested the battery and told me it was 100% normal (see attached printout). The battery specialist (I was told he has been doing this for 23 years) told me that large fluctuations are totally normal for this battery.

So my questions are:
- Do you think the battery specialist is right and I should not worry?
- Anyone else using a Noco Genius2 and getting to the green light?
- Any other trickle charger you have used on this car that does work fine?
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Thanks!

 

I was looking at the 12V battery and no where it says it's an AGM battery.

The battery should be a sealed acid lead battery and not AGM. Thoughts?

 

Thanks for the reply. According to my Lexus service representative: "It is an enhanced flooded battery using AGM technology." Probably needs to be verified...

 

This is what I found in an NX350h document from UK:

The NX350h also contains a sealed lead-acid 12 Volts battery. This 12 Volts auxiliary battery powers the vehicle electrical system similar to a conventional vehicle. As with other conventional vehicles, the auxiliary battery is grounded to the metal chassis of the vehicle.

 

The post from nx450PLUS at https://www.clublexus.com/forums/nx-...v-battery.html seems to indicate it is an AGM. I believe my Lexus rep asked his battery specialist before writing his reply saying it is an EFB using AGM...

 

Nx450plus said he needs a larger AGM battery. Didn't say the original battery is AGM.

​​​​​​I hope your rep is correct, but my research says different.

 

It's weird that the battery type and specs are not indicated in the manual and that it is so hard to get info about it! I hope someone on this board can provide the full specs...

 

Most (if not all ) types of FLA battery testers check starting amps only (which is only needed for a few seconds to spin the starter) vs the actual battery capacity in AH. For a typical ICE car with starter this is a reasonable test. But for a hybrid, we really need to know the total capacity left in the battery, since the hybrid battery never sees that very heavy, but short term load from a starter. It just need to run the computer systems and prepare the hybrid system for operation.

Ir ia possible for lead acid battery to have adequate cranking amps, but have lost some of its AH capacity. And still test good.. In other words, what we want to test for a "good" hybrid 12V battery is a cross country runner vs a sprinter test.

That kind of test takes a lot longer, since you have to actually measure the capacity being drawn from the battery not just a few seconds of amps to spin a starter

I have the 350h with a non-AGM, non-sealed 47/H5. The Lexus parts department explicitly said the factory battery was not an AGM in my 350H by ViN. I too have noticed also OP voltage readings from very low to a fully charged battery and if I do much of anything on the car without it being in READY mode, the battery quickly drains to the posts the doors/trunk will not operate or then car will not go to READY mode.

If I do anything for more than a very few minutes, the car just has to be put in READy mode to let the hybrid system charge the battery. And my 2017 CRV non-hybrid has the same propensity to drain the battery quickly, if the engine was not running also. Just seems be the trend is gong in newer cars.

 

All I knew at the time was that the OEM 12v battery on the plug in hybrid had only 345 cold cranking amps and I needed as many as I could get (>=600). I dumped the OEM battery at the battery place. I know very little about batteries otherwise

 

Thanks for clarifying my understanding as well.

 

Maybe you should take a photo of yours. Maybe you do have a different battery.

 

You have to have the car in ACC (or READY) mode for the power outlet to be active, no? In ACC there are various systems drawing power from the 12V battery; so, you're measurement will be low. To get an accurate measurement, everything has to be off... and that is tricky with the door/hood/trunk open. [The OBDII port has 12V at all times... depending on how determined you are to use what you have... you could stick some wire or something in the correct OBDII pin locations and hold them to your power outlet meter... you can trip the door/hood/trunk latches so everything settles down faster (don't forget to "untrip" them before closing up).]

I'd rather show up at the dealer with the battery drained... like what is apparently normal. I have done this, and they still say the battery is good. (They also told me the battery had been replaced before I ever got the car... at the port?)
I think like @gcskoor ; but IDK, it says they charged it for ~16 minutes and reserve health is OK.

[If someone has a good relationship with their dealer/tech (or wants to pester them)... ask them to hook up their computer; connect to the "Hybrid Control" ECU; and explain why my (and probably your) "Auxiliary Battery Capacity after IG ON" and "Auxiliary Battery Capacity after IG OFF" is one tenth or less than "Auxiliary Battery Status of Full Charge" which used to be 55 Ah but is now 46.5 Ah. Even when I never use ACC. I hate going to the dealer sooo much.]

 

I do not believe any NX, including hybrids come with AGM batteries. Look up the part number on the battery in the trunk.

 

Thanks for all the info! I don’t see any serial number or model number label at the top of the battery. However the following is shown:

P5 20HR 60Ah CCA 345A(EN) 360LN2-MF. (model number?)

There is some other information but it’s all in Japanese...

 

I thought I saw a higher CCA on my battery for my Hybrid NX(made in Canada) so I just went and checked. It's a 563A and yes a lead(Pb) acid battery on mine as you can tell by the recycle info.

Not sure why they would go with a smaller 12V battery in the 450h's as the same engine. Maybe mine is bigger due to options like ML and PANO. Battery Date of man 12/27/22- M45 and is made by the "Clarios" battery manufacturer. Googling them they say they make 1/3 of all oem batteries worldwide and making batteries for 130 years. They list that they are the manufacturer of Optima batteries too.
Never heard of them but they have a manufacturing plant in Holland Michigan which might be the M45 after man date. lol
They apparently bought out or changed their name from Johnson Controls, which I have heard of..
No problems so far.

Curious to see what other batteries they used?
With hold down on first pic and taken off in second pic.