RX400h replacement 12v battery

[elche286 2]

Hi Guys,

Done so much 'googling' on this one.

I know this Battery fits:

Optima battery FITS Lexus RX 400H 3.3 Petrol 2006 | eBay

Does anyone know for sure a cheaper option that works / fits?

Thanks in advance

Che

[ColinBarber 2,087]

I used a Bosch S4 model 158 when I replaced the Battery on my old 400h.

This was 6+ years ago so I'm sure the price has gone up but the 400h just uses a standard wet Battery - nothing expensive, although you could go for something like an Optima which will cope with deep cycling if you aren't using your vehicle much during lockdown.

[Barry14UK 504]

Only 38Ah on that Optima.    People with the 51Ah Battery as originally fitted in the RX450h complain  that depletes too quickly if car left at airport or not regularly charged by Lexus procedure,  trickle charger or solar panel.  I am pretty sure that even the Prius has a 45Ah battery.   The Optima would serve but I am sure you could do better given the available space in the RX400h and the stated fact that a standard flooded lead acid would be suitable and might also be cheaper.

[ColinBarber 2,087]

1 hour ago, Barry14UK said:

Only 38Ah on that Optima.    People with the 51Ah battery as originally fitted in the RX450h complain  that depletes too quickly if car left at airport or not regularly charged by Lexus procedure,  trickle charger or solar panel.  I am pretty sure that even the Prius has a 45Ah battery.   The Optima would serve but I am sure you could do better given the available space in the RX400h and the stated fact that a standard flooded lead acid would be suitable and might also be cheaper.

The standard Battery for the 400h is rated as 38 Ah for 5HR. The Prius III is 36 Ah and the Prius IV is 30 Ah (but 45 @ 20HR).

The RX450h series III is 43 Ah for 5HR - which may be around 51 Ah for 20HR.

The RX450h series IV is 60 Ah for 20HR. Seems Toyota are starting to use 20HR rating on newer models, which makes sense, especially for a hybrid that doesn't/shouldn't need a fast discharge rate for the aux Battery.

 

The problem is that capacities are often quoted at different discharge rates and therefore difficult to compare. Typically the capacity is directly linked to the size of the Battery, so will always be similar if you get one of the same dimensions.

The 400h doesn't have smart lock/unlock so there isn't as much Battery drain compared to the 450h.

[Djwbiker 13]

I have recently changed the 12v Battery for a Toyota one from lexuspartsdirect, £57 with 3 days delivery so pretty good. The previous one was 3 years old and was not at fully recharging hence the change. Like a lot of members at the moment I only do a couple short journeys a week so try to do a longer one once a week. Would it be beneficial to help discharge it a bit before the longer journey or connecting my battery charger by leaving the lights/radio ???on for 10-15 mins?

Any advice from you technical chaps appreciated.

thanks

 

 

 

[ColinBarber 2,087]

48 minutes ago, Djwbiker said:

Would it be beneficial to help discharge it a bit before the longer journey or connecting my battery charger by leaving the lights/radio ???on for 10-15 mins?

No, there is no benefit it doing that. You would be better off charging your Battery on a smart charger for several hours every few weeks to get it to 100% charge, something the vehicle is unlikely to do by just running it on a long journey once a week - the final 10% charge is done slowly so it is unlikely you will ever achieve it that way.

[Barry14UK 504]

 

9 hours ago, ColinBarber said:

The standard battery for the 400h is rated as 38 Ah for 5HR. The Prius III is 36 Ah and the Prius IV is 30 Ah (but 45 @ 20HR).

The RX450h series III is 43 Ah for 5HR - which may be around 51 Ah for 20HR.

The RX450h series IV is 60 Ah for 20HR. Seems Toyota are starting to use 20HR rating on newer models, which makes sense, especially for a hybrid that doesn't/shouldn't need a fast discharge rate for the aux battery.

 

The problem is that capacities are often quoted at different discharge rates and therefore difficult to compare. Typically the capacity is directly linked to the size of the battery, so will always be similar if you get one of the same dimensions.

The 400h doesn't have smart lock/unlock so there isn't as much battery drain compared to the 450h.

 

Yes very few battery manufacturers quote just 5HR, some both 5HR and 20HR but vast majority now just the capacity at 20HR rate which seems to be becoming the accepted reference.

The original Pan Battery on my 3 series RX450h just shows 51Ah.

Interesting the 4 series RX450h has gone to 60Ah.  I have worked out how I can fit a 60Ah 027  AMG Battery into my car but before doing so I want to check whether I can fit a 75Ah AGM one.  This would need the Battery compartment being extended but I will have to remove the undertray to check this is possible.  It would  also be necessary to move the spare wheel fixing over so the wheel avoids fouling the Battery.  The Battery I would be looking at would be the Hankook AXS65D26L which is designated for Hybrid Electric Vehicles and is 260mm long.  For those that are happy with a flooded lead acid there is more choice. 

 

 

 

 

 

[elche286 2]

6 hours ago, Djwbiker said:

I have recently changed the 12v battery for a Toyota one from lexuspartsdirect, £57 with 3 days delivery so pretty good. The previous one was 3 years old and was not at fully recharging hence the change. Like a lot of members at the moment I only do a couple short journeys a week so try to do a longer one once a week. Would it be beneficial to help discharge it a bit before the longer journey or connecting my battery charger by leaving the lights/radio ???on for 10-15 mins?

Any advice from you technical chaps appreciated.

thanks

 

 

 

Hi,

Thanks for he reply.

Have you fitted the Battery now and is working ok?

If so would you have the link as on LPD website for Rx400h (phase2) is

Lexus RX Electrical Parts & Accessories | Lexus Parts Direct

No 12v Battery..?

Thanks in advance

Che

 

[Herbie 1,818]

2 minutes ago, elche286 said:

If so would you have the link as on LPD website for Rx400h (phase2) is

Lexus RX Electrical Parts & Accessories | Lexus Parts Direct

No 12v battery..?

That's because they seem to have placed the batteries in the 'Engine' section instead of 'Electrical' so just go back there and look in the engine section.

[elche286 2]

2 hours ago, Herbie said:

That's because they seem to have placed the batteries in the 'Engine' section instead of 'Electrical' so just go back there and look in the engine section.

well that makes sense.....

\Thanks

[elche286 2]

On 2/7/2021 at 6:09 PM, Djwbiker said:

I have recently changed the 12v battery for a Toyota one from lexuspartsdirect, £57 with 3 days delivery so pretty good. The previous one was 3 years old and was not at fully recharging hence the change. Like a lot of members at the moment I only do a couple short journeys a week so try to do a longer one once a week. Would it be beneficial to help discharge it a bit before the longer journey or connecting my battery charger by leaving the lights/radio ???on for 10-15 mins?

Any advice from you technical chaps appreciated.

thanks

 

 

 

Hi DJ,

Can I ask if you went for this one then

Lexus RX Phase 2 12v Battery | 28800-YZZJU | Lexus Parts Direct

I think our RX's use identical 12V batteries. That is currently £54.

Do any mbr's know how this compares in the long-term to their other (more expensive option)

Lexus RX Phase 2 12V Battery | 28800-YZZZL | Lexus Parts Direct

Many thanks in advance.

Che

 

[Djwbiker 13]

Hi Che

The cheaper one is for 2005-2008 models which I have, the more expensive is for 2003-2005 I don't know why there is a difference.

If you see the post reply from Colin Barber his advice to my question was to put the Battery on a smart charger rather than a longer run. I have now done this twice this week and unfortunately the recharge leaves the Battery at as 'weak' status on my charger showing only at  12.15 v also confirmed with the reading on my multimeter.

This was a new Battery only installed for 6 weeks so not impressed. I am in discussion with LPD about the situation so will keep you posted.

cheers

Dave

[elche286 2]

Hi Dave,

Thanks for your quick reply - and clarification of the slight difference between our issues.

I've had my 03-08 RX400h (which was actually registered on an 09 Plate), for 4 years, and luckily have not had ay 12v Battery discharge issues, which if |I understand your post is your problem i.e. bat going flat every few week. 

I just wanted to get a reliable replacement Battery w/o paying over £100 for the 'yellow one Optima?)', as I know mine will have to be replaced soon.

It came with the car so:

a) Seems to work w/o issue, and 

b) In my Rx400h (at least) must have lasted at least 4 years.

I did know about the issue of Rx400h 12 bats going flat (some users said in a week), if the car was not used.

So for holiday's etc I decided to get a small solar bat charger - some examples here:

Amazon.co.uk : Solar Panel Battery Charger

It just plugs into the RX's OBD(?) port. This is located in the car (drivers side corner half way down).

I wonder doing this would at least give you a temp solution to the problem?

However, I must stress that lockdown has significantly reduced my mileage / frequency of using my 400h and it never goes flat.

As such,  I don't think your Battery should be going flat if you don't use ur Rx it much - could there me another issue causing this?

For example I believe that some dashcams can cause this.

As an aside, what's the £57 Battery like?

Dunno if I'll just get the same spec as the Bosch that's in as that seems to have lasted w/o any issues.

thanks 

Jon

 

[elche286 2]

2 hours ago, Djwbiker said:

Hi Che

The cheaper one is for 2005-2008 models which I have, the more expensive is for 2003-2005 I don't know why there is a difference.

If you see the post reply from Colin Barber his advice to my question was to put the battery on a smart charger rather than a longer run. I have now done this twice this week and unfortunately the recharge leaves the battery at as 'weak' status on my charger showing only at  12.15 v also confirmed with the reading on my multimeter.

This was a new battery only installed for 6 weeks so not impressed. I am in discussion with LPD about the situation so will keep you posted.

cheers

Dave

Sorry Dave - late and lazy; hence didn't read the whole thing.

I think that Bosch is still in production, but agree that you should run some tests to  try any obv faults.

Doesn't inspire confidence in the LPD product then....

I note CB's adv to smart charge  twice a week - but after this you are still getting a low voltage reading on the bat with you're MM.

Could this be a faulty Battery or charger then?

I'm not sure how 'smart' chargers work vis-à-vis 'traditional' overnight trickle chargers)

If when charging the bat is disconnected from the car (which surely a lexus owner should not have to do twice a week), surely it can only be faulty bat, charger or meter.

If smart meters charge the bat 'in situ' then I suppose this does not rule out a 'in-car' charge or discharge issue.......

Kind regards

Jon

 

[Barry14UK 504]

Perhaps the main advantage of a smart charger is that it senses the state of the Battery.  When connected to a Battery with low charge it will charge it at a rate up to the maximum of the charger until the Battery is almost fully charged when it will reduce the rate of charge until the Battery is fully charged.  Also, a smart charger can be left connected to a Battery via a 240v supply long term where it will just keep it topped up as necessary.  A decent smart charger will have a mode for checking AGM and free flow lead acid batteries as well one for reconditioning.  A smart charger also prevents overcharging and 'gassing' which is particularly important in an AMG or maintenance free. Battery.

[elche286 2]

On 2/11/2021 at 12:03 AM, Djwbiker said:

Hi Che

The cheaper one is for 2005-2008 models which I have, the more expensive is for 2003-2005 I don't know why there is a difference.

If you see the post reply from Colin Barber his advice to my question was to put the battery on a smart charger rather than a longer run. I have now done this twice this week and unfortunately the recharge leaves the battery at as 'weak' status on my charger showing only at  12.15 v also confirmed with the reading on my multimeter.

This was a new battery only installed for 6 weeks so not impressed. I am in discussion with LPD about the situation so will keep you posted.

cheers

Dave

Hi Dave,

Thanks for clarifying that - weird as I would have thought same 12v bat went in all the Rx400h's from 03-08...?

I know I'm going to have to replace mine soon. I have seen the bosch one on ebay for about £60 so might go with that.

I hope you manage to sort your problem out - surely if you didn't have this problem with your old 12v bat then it's got to be that, that is the issue......?

Best wishes

Jon

[ColinBarber 2,087]

On 2/11/2021 at 12:03 AM, Djwbiker said:

The cheaper one is for 2005-2008 models which I have, the more expensive is for 2003-2005 I don't know why there is a difference

The cheaper one is the 38/45 Ah (5HR/20HR) one for the 400h. 28800-YZZZV

The other is higher capacity and for the RX300. It probably won't physically fit in the 400h.

[elche286 2]

7 minutes ago, ColinBarber said:

The cheaper one is the 38/45 Ah (5HR/20HR) one for the 400h. 28800-YZZZV

The other is higher capacity and for the RX300. It probably won't physically fit in the 400h.

Thanks Colin.

Who would have thought a simple 12v bat change could be so confusing - unbelievable

So I'm thinking this should fit an 08 rx400h?

S4 021 Bosch Car Battery 12V 45Ah Type 048 S4021 (tayna.co.uk)

Do u agree?

Thanks

Jon  

[ColinBarber 2,087]

45 minutes ago, elche286 said:

S4 021 Bosch Car Battery 12V 45Ah Type 048 S4021 (tayna.co.uk)

Do u agree?

Yes, that is I believe the correct one. The correct size and no sill at the bottom. Worth double checking your existing Battery has the +ve terminal on the right hand just to make double sure.

[elche286 2]

21 minutes ago, ColinBarber said:

Yes, that is I believe the correct one. The correct size and no sill at the bottom. Worth double checking your existing battery has the +ve terminal on the right hand just to make double sure.

Cheers Colin,

A huge help

Stay safe

Jon