12v battery maintenance

[IanML]

Probably the OBD2 socket which is usually at the lower edge of the dash close to the driver's knee.

[ColinB]

23 hours ago, Wrighty69 said:

I have been in contact with Toyota and they said "get a solar charger that plugs into the DL3 diagnostic socket and that will charge the battery with the ignition off".

Now I just need to locate the DL3 Diagnostic Socket and a suitable solar charger.

 

I bought a standard solar panel from Amazon and an adaptor from Halfords (also available elsewhere) : https://www.halfords.com/motoring/battery-maintenance/battery-accessories/ring-obd-power-cable-for-solar-battery-maintainers-983932.html

There is an Obd port on the bottom of the RH day on my '21 model, but to date I haven't tried using it as I've been using my car enough to not have any trouble yet 🤞

Colin

[Griff_4988]

22 hours ago, ColinB said:

I bought a standard solar panel from Amazon and an adaptor from Halfords (also available elsewhere) : https://www.halfords.com/motoring/battery-maintenance/battery-accessories/ring-obd-power-cable-for-solar-battery-maintainers-983932.html

There is an Obd port on the bottom of the RH day on my '21 model, but to date I haven't tried using it as I've been using my car enough to not have any trouble yet 🤞

Colin

Appreciate the info on this thanks, I didn’t know these charging connectors existed. We sometimes take long holidays away, when my car remains unused for 4 to 6 weeks at a time. With other makes of cars I had before getting the RAV4, I’ve lifted the bonnet and connected my solar charger directly across the Battery. I won’t have to now!

[Terry10]

Hello all. Just suffered my first flat 12 volt Battery failure in 3 years and 4 months last Saturday morning. Couldn't have happened at a worse time as we had friends down from up country for the weekend and we were going to take them out in the Rav for the day. Ended up going in their car.This has led me into a lot of research online on this problem.When we got back a neighbour had a jump start pack so problem solved.Left it in ready mode for an hour and all is now fine again.

I have now ordered a jump start pack that will live in the glovebox.

What I can't understand after reading this thread and others quite extensively is why are people buying Battery trickle chargers when you can just leave the car in ready mode for an hour.

When the Battery goes flat on you then surely you just want to get it started and be on your way rather than sit there waiting for it to charge up.The only reason that I left the car in ready mode was because we weren't going anywhere else for the rest of the day.

I am sure someone will correct me if I am wrong but from what I can see these batteries have a life of 3 to 5 years, so I suspect that I am going to get this issue a little more in the future. Don't think that they are that expensive anyway and I guess that they will be classed as consumables.

regards Terry.

 

 

 

[Roy124]

13 minutes ago, Terry10 said:

What I can't understand after reading this thread and others quite extensively is why are people buying battery trickle chargers when you can just leave the car in ready mode for an hour.

There are several reasons why a trickle charger is better than Ready Mode.  The first is the time factor.   Do you want to sit in or keep an eye on your car while it is switched on? With on-street parking it is not really an option.

If you have open air parking the trickle charger is a better solution  than Ready mode.

If you are away on holiday and have open air parking a trickle charger is your only option apart from a jump starter.

The jump starter is good but it does not prevent Battery damage should your Battery run flat.

In your case that flat Battery was a warning.

[philip42h]

11 minutes ago, Terry10 said:

What I can't understand ... is why are people buying battery trickle chargers when you can just leave the car in ready mode for an hour.

It all depends on what 'problem' you are needing to address:

• If I were planning to leave my car standing (in my garage) for an extended period I would use a mains powered smart charger to maintain the 12V auxiliary Battery.
• Folk leaving their cars in the open air - in a long stay car park at the airport, say - would be wise to use a solar powered trickle charger to maintain the 12V auxiliary Battery.
• If I were to get back to my car and find for some less explicable reason that the 12V auxiliary Battery is down low enough not to get the car into Ready mode I would use a jump start pack to get going again to save waiting for the breakdown service (and then, probably, use a mains powered smart charger to ensure that the 12V auxiliary battery was fully charged once more.

The only time that I would routinely leave the car in Ready mode for an hour is when I want to update the maps! And then, topping up the 12V auxiliary battery is a side product ... 😉

[Terry10]

Just to clarify, my Battery wasn't totally flat as the dash lights were coming on and I opened the car with no problem.

When I pressed start it would not go into ready mode and I got a clicking noise that sounded like a solenoid trying to switch.

totally understand peoples problems reference leaving the car in ready mode in car parks etc. but would point out that this appears to be the recommended method to charge this Battery by Toyota.

This issue does just happen out of the blue as I hadn't changed any of my driving/ distance/ journeys at all.

It will be interesting to see what happens in coming weeks but whatever I am now prepared and won't be stuck anywhere.

Terry

[Roy124]

1 hour ago, Terry10 said:

my battery wasn't totally flat as the dash lights were coming on and I opened the car with no problem.

When I pressed start it would not go into ready mode and I got a clicking noise that sounded like a solenoid trying to switch.

Not completely flat, true, but at a low voltage it is still damaged and giving you a message.   Using a charger might repair the Battery and stave off failure.

[Terry10]

Sorry but I really can't understand how a charger will repair a Battery that is partially discharged.Certainly didn't have any info come up saying my Battery is damaged, it didn't even say why it wasn't going into ready mode.

Bottom line is that it was the age old problem that many people on this forum get with this model and it is a case of put up with it or change your car.

If I have to purchase a new Battery in the coming months then so be it.Can't see Toyota replacing that sort of thing F.O.C.

Watch this space 😎

Terry

[ernieb]

Some of the modern charger can be set to perform a cycle of discharging and reconditioning the Battery before charging. Not sure of the physics but there are a few out there which also match the batteries chemistry - so standard/AGM etc.

[Hayzee]

1 hour ago, ernieb said:

Some of the modern charger can be set to perform a cycle of discharging and reconditioning the battery before charging. Not sure of the physics but there are a few out there which also match the batteries chemistry - so standard/AGM etc.

Ernie are the batteries are non AGM?

[Roy124]

49 minutes ago, Hayzee said:

Ernie are the batteries are non AGM?

I believe they are not AGM and did read  that they are Calcium batteries which are better

A calcium Battery is a lead acid Battery with a calcium component (around 1%) added to both the positive and negative plates. This works to reduce water loss through gassing in the Battery and allows the battery container to be fully sealed and maintenance-free.

[philip42h]

1 hour ago, Hayzee said:

Ernie are the batteries are non AGM?

The 12V auxiliary Battery in the back of a RAV is a bog standard sealed lead acid Battery ... 🙂

[IanML]

5 hours ago, ernieb said:

Some of the modern charger can be set to perform a cycle of discharging and reconditioning the Battery before charging. Not sure of the physics but there are a few out there which also match the batteries chemistry - so standard/AGM etc.

I don't know all the details, but the process is known as a "gassing charge".  It restores much of the battery's original capacity, as long as the plates have not been damaged by overheating or excessive discharge.

The thing to be aware of is that it does liberate a fair amount of hydrogen, so installations which are not well ventilated (such as under seating in the cabin) are unsuited.  I don't know where the RAV4's Battery is - in the hybrid Yaris it is beneath the rear seat.  That may explain the preference for recharging with the car's system, rather than a trickle charger, although I think the latter would be ok provided the reconditioning cycle was not used.

[ernieb]

10 hours ago, Hayzee said:

Ernie are the batteries are non AGM?

As others have said not AGM. When I bought my charger I looked at the car spec and found via lots of spec sheets it was AGM but it turned out this was not the case. I believe you can get an AGM version of the Battery but not sure the car's set up to charge it correctly. @philip42h had a link to data when I was going through this I seem to remember???

[robo1]

And the woolly response from Toyota in 2021 when I asked them what type of Battery was fitted 

 

[Roy124]

46 minutes ago, robo1 said:

And the woolly response from Toyota in 2021 when I asked them what type of battery was fitted 

 

I got a similar response from CTEK when I asked which option to use with a Calcium Battery - ask Toyota. 

It seems from my search yesterday that a PbCa Battery should probably use the lead acid setting

Lead-acid batteries suffer from relatively short cycle lifespan (usually less than 500 deep cycles) and overall lifespan (due to the "double sulfation" in the discharged state), as well as long charging times.

A 5 year life would equate to 100 deep cycles per year.  What, in this context, is a deep cycle?  In the ICE case might this cold starts,

In the Toyota case what does this mean?

[philip42h]

10 hours ago, philip42h said:

The 12V auxiliary battery in the back of a RAV is a bog standard sealed maintenance free lead acid battery ... 🙂

I mis-spoke - see correction above - and picture below. 😉

The really simple solution, for anyone who really cares, is to simply look in the car. The picture below is of the auxiliary Battery in the boot of my car:

You can read the instructions to 'add distilled water' and to 'keep the vent caps tight and level'.

That is what was fitted by Toyota in Japan. If we try to buy a replacement here in Europe we are most likely to be offered an AGM alternative. I don't know what a dealer would fit as a replacement ...

IIRC the PHEV has a slightly larger capacity Battery, and, not that it is relevant in the RAV4 forum, other models built elsewhere will have different batteries again ... 😉

[robo1]

1 hour ago, Roy124 said:

I got a similar response from CTEK when I asked which option to use with a Calcium battery - ask Toyota. 

This is the response from CTEK I received. If in doubt charge using the standard setting appears to be the advice 

[philip42h]

8 minutes ago, robo1 said:

This is the response from CTEK I received. If in doubt charge using the standard setting appears to be the advice 

That is correct.

The additional options allow us to charge specific Battery types at a higher voltage and thus slightly more quickly or completely. The 'standard' setting can be used safely and adequately on all 12V Battery types.

The converse is not true - using the AGM setting on a standard Battery might cause gassing which is not something that you'd want to do in the boot of your RAV4. But, honestly, even then the risk is small ...

[ToyotaFanDriver]

Does turning on remote climate help to maintain the Battery in anyway or is it just a drain? I mean they car will be on for 20 mins and I hear the engine on so I assume there is some charge going to the Battery?

[robo1]

The 12v Battery is charged from the traction Battery so it gets charged whenever the car is in ready mode irrespective of if the engine is running. No one seems to know at what rate the traction Battery charges the 12v battery but I suspect it’s a lot less than an alternator hence the flat batteries. 

[philip42h]

25 minutes ago, robo1 said:

No one seems to know at what rate the traction battery charges the 12v battery but I suspect it’s a lot less than an alternator hence the flat batteries.

One of our number posted measurements a while back. In effect, the DC-DC Converter acts as / includes the equivalent of a smart charger - i.e. it charges the auxiliary Battery rapidly when it is at a lower state of charge and at a lower rate as the Battery approaches 'full'. In addition, it supplies the full demand from the 12V systems while the car is running.

So, it's at least as good as an alternator would be ... 😉

[DRS300]

Modern chargers do seem to be able to get some decent life back into a seemingly defunct 12v Battery. The other car in the family is an EV which locked me out one day, all electrics dead. Recharged with a charger I had had a number of years and all OK for a month, then dead again. Bit the bullet and got a modern charger (NOCO) and recharged for a few hours, worked OK but dead again after a month or so. Put it on charge for a couple of days and no problems for the last two years. All recharges done on the bench using the default setting. 

With the current RAV4 the Battery in the boot means that you can hook up a charger to a portable power station (campers/country dwellers) so no trailing cables.

[nlee]

18 hours ago, ToyotaFanDriver said:

Does turning on remote climate help to maintain the battery in anyway or is it just a drain? I mean they car will be on for 20 mins and I hear the engine on so I assume there is some charge going to the battery?

Yes it does seem to. The voltage isn't as high as when in ready mode, maybe more like a trickle charge. Similar on the PHEV during charging, when the Battery cooling/heating is running.