Toyota RAV4 Battery Keeps Going Flat :(
Patrick James
My Mum has had a Toyota RAV4 for over ten years. Some time ago the
original battery was replaced with another which would go flat very
frequently, so she replaced that one with another and that one goes
flat just as often.
The batteries seem to go flat if the car is not being used even for
quite short periods. She has to take her RAV4 out every day just to
make sure the battery is kept charged.
She has tried to get the original battery as supplied with the Toyota
in the first place but for some reason that does not seem to be
possible.
I had thought that maybe there is a problem with the alternator but
then, it seems that the battery does charge up when she is out driving.
She does use the car frequently but always short journeys.
It seems that the batteries go flat very easily on this car.
I wonder if anyone here might have some suggestions for a solution to
the problem?
Thank you.
--
Patrick
<http://www.patrickjames.co.uk>
Harry Bloomfield
> I wonder if anyone here might have some suggestions for a solution to the
> problem?
>
> Thank you.
You need to check the level of discharge when the car is parked up. It
should be less than around 60mA, after being stood for an hour - once
all of the electronics have fallen into sleep mode. A short term fix,
might be to disconnect the battery everytime it is to be parked for a
period unused.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
Dave Plowman (News)
Patrick James <email.no...@gmail.com> wrote:
> The batteries seem to go flat if the car is not being used even for
> quite short periods. She has to take her RAV4 out every day just to
> make sure the battery is kept charged.
If the battery is going flat that quickly, something is very wrong. Modern
cars have electronics that draw current even when everything is switched
off - but should be able to cope with at least 3 weeks of not being
started.
As Harry says, you need to get the quiescent current measured. It's likely
several amps in your case. It should be perhaps 0.05 amps
--
*He who laughs last has just realised the joke.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Graham.
"Patrick James" <email.no...@gmail.com> wrote in message news:8msu9h...@mid.individual.net...
Conceder any after-market devices that you might have had fitted as possible
suspects. I'm thinking of alarms and hands free kits.
Also make sure you haven't simply got a "fridge paradox" going on with
a festoon bulb in the boot, or under the bonnet.
--
Graham.
%Profound_observation%
Chris Whelan
As others have said, the most likely problem is something draining
current when parked, but it is also possible for an alternator to fail in
a way that it produces enough current to extinguish the no-charge light,
but insufficient to keep the battery fully charged. Another possibility
is a slipping auxiliary drive belt, but you can usually hear that. (The
belt is actually a service replacement item on the RAV, rather than just
something to be checked.)
Both problems are easy to check if you have a multi-meter, and the skills
to use one. Otherwise, perhaps it might be worth trying to find a mobile
auto electrician to check it out. The cost can be offset against having
to drive the car every day!
Chris
--
Remove prejudice to reply.
Patrick James
> You need to check the level of discharge when the car is parked up. It
> should be less than around 60mA, after being stood for an hour - once
> all of the electronics have fallen into sleep mode. A short term fix,
> might be to disconnect the battery everytime it is to be parked for a
> period unused.
Thank you Harry and also the other replies from Dave, Graham and Chris.
I get the picture I think and I am going to ask my Mum to contact a car
electrician with these suggestions, the main one being to see if
something is draining the battery when the car is parked.
My Mum is in Northern Ireland whereas I am in England so I can't easily
do this myself but she is well up to it she just needs a general idea
of what might be wrong and I now have this.
--
Patrick
<http://www.patrickjames.co.uk>
Dave Plowman (News)
Get her to ask the auto electrician for a 'quiescent current check' on the
battery. If he doesn't know what you mean, find one who does.
--
*Vegetarians taste great*
Patrick James
> Get her to ask the auto electrician for a 'quiescent current check' on the
> battery. If he doesn't know what you mean, find one who does.
Will do :)
--
Patrick
<http://www.patrickjames.co.uk>
Grimly Curmudgeon
drugs began to take hold. I remember Patrick James
<email.no...@gmail.com> saying something like:
>I had thought that maybe there is a problem with the alternator but
>then, it seems that the battery does charge up when she is out driving.
>
>She does use the car frequently but always short journeys.
>
>It seems that the batteries go flat very easily on this car.
>
>I wonder if anyone here might have some suggestions for a solution to
>the problem?
Two main causes that I see as possible...
1. Chances are the batteries she's getting are calcium ones, which have
a charging spec of 14.8Volts. An old alternator/regulator doesn't put
that much into them, more like 14.3Volts and this is compounded by the
short journeys, so the battery is never fully charged and is further
drained by the stop/start nature of the trips.
It's possible to get a replacement regulator to match the calcium
battery, but you have to piss around a bit trying to find one. Otoh, a
decent auto-electrician should know about it and be able to sort one
out.
2. There might be a fault in the existing regulator or a duff diode
which is allowing battery discharge through the alternator when the
vehicle is parked up.
Dave Plowman (News)
Grimly Curmudgeon <grimly...@REMOVEgmail.com> wrote:
> 1. Chances are the batteries she's getting are calcium ones, which have
> a charging spec of 14.8Volts. An old alternator/regulator doesn't put
> that much into them, more like 14.3Volts and this is compounded by the
> short journeys, so the battery is never fully charged and is further
> drained by the stop/start nature of the trips.
> It's possible to get a replacement regulator to match the calcium
> battery, but you have to piss around a bit trying to find one. Otoh, a
> decent auto-electrician should know about it and be able to sort one
> out.
IMHO, an urban myth. Very few car batteries are ever at 100% charge -
except after a long run. So the few percent difference between a so called
calcium type and normal isn't going to make any difference. If it did,
companies like Halfords wouldn't sell them due to excessive warranty
claims.
--
*I have plenty of talent and vision. I just don't care.
Grimly Curmudgeon
<da...@davenoise.co.uk> saying something like:
>IMHO, an urban myth. Very few car batteries are ever at 100% charge -
>except after a long run. So the few percent difference between a so called
>calcium type and normal isn't going to make any difference. If it did,
>companies like Halfords wouldn't sell them due to excessive warranty
>claims.
Nonetheless, it is true, and allied with stop/start behaviour, simply
compounds the problem.
It seems that calcium/calcium batteries don't take kindly to slight
undercharging and sulphation becomes a problem sooner than it should. A
decent calcium-matched charging system should keep the battery going for
well after the warranty period. In my case, a calcium battery in my
Tranny is now nine years old and still cranking away like a good'un.
Happily for Halfords and the like, the owner just buys another one from
them. Even if the battery fails within the warranty period, the
no-quibble replacement policy of many battery chains just hoovers them
up. I would suppose by now the majority of Halfords customers are
actually driving calcium-compatible cars, so the odd older car with
lower voltage charging system doesn't impact the the returns all that
much.
As for the rest of us with older alternators on our ShiteOldClassics, we
need to replace the regulator or occasionally give a proper 14.8V top-up
charge to keep the battery happy. As you know, the Aldidl charger does
just that.
Dave Plowman (News)
Grimly Curmudgeon <grimly...@REMOVEgmail.com> wrote:
> >IMHO, an urban myth. Very few car batteries are ever at 100% charge -
> >except after a long run. So the few percent difference between a so
> >called calcium type and normal isn't going to make any difference. If
> >it did, companies like Halfords wouldn't sell them due to excessive
> >warranty claims.
> Nonetheless, it is true, and allied with stop/start behaviour, simply
> compounds the problem.
> It seems that calcium/calcium batteries don't take kindly to slight
> undercharging and sulphation becomes a problem sooner than it should. A
> decent calcium-matched charging system should keep the battery going for
> well after the warranty period. In my case, a calcium battery in my
> Tranny is now nine years old and still cranking away like a good'un.
> Happily for Halfords and the like, the owner just buys another one from
> them. Even if the battery fails within the warranty period, the
> no-quibble replacement policy of many battery chains just hoovers them
> up. I would suppose by now the majority of Halfords customers are
> actually driving calcium-compatible cars, so the odd older car with
> lower voltage charging system doesn't impact the the returns all that
> much.
The calcium battery in my 25 year old SD1 is 7 years old and still ok.
Despite having been run pretty flat on a number of occasions. ;-)
FWIW, any time I look at the actual charging voltage on my BMW which has a
pretty massive alternator, it's 13.8. Just what I'd expect with a fully
charged battery.
--
*How come you never hear about gruntled employees? *
4square
wrote:
> In article <n2cpg6ls4t3qlqptsh1hfv82s3k6k4r...@4ax.com>,
> To e-mail, change noise into sound.- Hide quoted text -
>
> - Show quoted text -
I had a Cavalier on which battery kept going flat, turned out to be
the heated rear window relay was sticking 'on' and not releasing when
ignition or its own switch were turned to off position.