Jump to content

  •  

Show
Photo
- - - - -

How Long Should A Battery Hold Its Charge For?


  • Please log in to reply
23 replies to this topic

#1 Hoovie

Hoovie

    I Like Cat Trees!

  • Banned
  • PipPipPipPipPipPipPipPip
  • 4,277 posts
  • First Name:David
  • Gender*:Male
  • Year: 2013
  • Location: Berwickshire

Posted 26 March 2008 - 07:58 AM

Got a May 2005 2.0 VVTi RAV4 and in Feb 2007, it had a new battery fitted (Battery was dead trying to start car, RAC came out to jump it, tested battery and pronounced faulty, Mr T replaced)

Now my driving habits haven't really changed that much in the last couple of years - car is usually sitting in driveway for a few days unused or I am doing 300 miles in a day, but Jan this year, Battery failed to start car, RAC came out to jump, tested battery, pronounced the replacement battery (1 year old now) faulty - This time Mr T say Computer Says No, Toyota test says battery not faulty, just drained through lack of use.

I accept this and car is ok, but on Sunday, cleaning out car and listening to radio in it - after just 10 minutes, radio goes off and battery is dead :o
Monday, RAC came out to jump it, tested battery and pronounced faulty - and when push him, is adament that battery is faulty.
So I drive to dealer (shut) then drive around a bit to recharge battery - maybe do about 40-50 miles altogether?
Tuesday, go to dealer and he looks at battery - again Computer Says No, Toyota test says battery not faulty, but must have been drained through lack of use - and on the Tuesday test was 85% charged.

So..... if I have a very drained battery that won't even let the radio work, would a 50 mile journey (jn daylight, no lights, no a/c) recharge battery back to 100% (I would have thought so ?)
Dealer reckons that the alarm draws 0.25A/Hr when set, so on a 45A battery as fitted to RAV4 VVTi, it takes 6A a day so if the car is not used for a number of days, the drain will be sufficient to stop it starting the car. He reckons maybe I should not set the alarm but use the key to lock it instead of remote.
Dealer is not being unhelpful, but says there is nothing he can do re replacement while the official Toyota tests report battery is not faulty.

What do you guys reckon? is the Battery faulty (and the RAC tests are right)? Is it just the way the car sits unused for maybe 3-4 days at a time with the alarm not draining the battery and that is just the way it is?
I would have thought I could leave a car for a week, maybe 2 weeks and just jump in and start it up! is that so unreasonable :huh:

Have something to contribute?

Sign in or register to start a topic...

Sign up to TOC Premium Membership To Remove These Ads

#2 T600

T600

    Top Rank Poster!

  • Advanced Members
  • PipPipPipPipPipPipPipPip
  • 2,965 posts
  • Gender*:Male
  • Toyota Model: Auris T180, MR2 GT T-Bar
  • Location: Nottinghamshire

Posted 26 March 2008 - 08:58 AM

You would think so wouldn't you. I've left plenty of cars at airports for two or three weeks or more and had not problems starting them on my return. And they all had alarms.

Alarm drawing .25 amps sounds very high to me; it might draw that or more when it's sounding, but should be nothing like that when it's just turned on and protecting the car.

Did they demonstrate this current draw to you? Look for other possible causes such as boot lights staying on.


But, if you don't use your car for a few days at a time, consider a battery charger; it's cheaper than driving the car just to charge it. Get a good make e.g. C-TEK and get a model that you can leave on all the time. These will top up a battery then let it discharge a bit, then top up again. You wouldn't have to use it all the time - just put it on for a few hours on one of the days that you're not using the car.

#3 daveh_rav4

daveh_rav4

    Advanced Club Member

  • Registered Member
  • PipPipPipPip
  • 122 posts
  • Gender*:Male
  • Toyota Model: Rav4 3dr 4.1 Freesport

Posted 26 March 2008 - 09:21 AM

Hi...
45a/hr battery..! Not enough capacity IMHO on a vehicle like a Rav. Talk to Mr T, advise him that you don't think the battery is 'fit for purpose' (under sale of goods act) as it keeps going flat. It is not unreasonable to leave the the car parked for a few days! Get a 75A/hr heavy duty battery... see if Mr. T will contribute towards the cost; or else your next car may be a Honda (with a big battery :) )

DaveH

Got a May 2005 2.0 VVTi RAV4 and in Feb 2007, it had a new battery fitted (Battery was dead trying to start car, RAC came out to jump it, tested battery and pronounced faulty, Mr T replaced)

Now my driving habits haven't really changed that much in the last couple of years - car is usually sitting in driveway for a few days unused or I am doing 300 miles in a day, but Jan this year, Battery failed to start car, RAC came out to jump, tested battery, pronounced the replacement battery (1 year old now) faulty - This time Mr T say Computer Says No, Toyota test says battery not faulty, just drained through lack of use.

I accept this and car is ok, but on Sunday, cleaning out car and listening to radio in it - after just 10 minutes, radio goes off and battery is dead :o
Monday, RAC came out to jump it, tested battery and pronounced faulty - and when push him, is adament that battery is faulty.
So I drive to dealer (shut) then drive around a bit to recharge battery - maybe do about 40-50 miles altogether?
Tuesday, go to dealer and he looks at battery - again Computer Says No, Toyota test says battery not faulty, but must have been drained through lack of use - and on the Tuesday test was 85% charged.

So..... if I have a very drained battery that won't even let the radio work, would a 50 mile journey (jn daylight, no lights, no a/c) recharge battery back to 100% (I would have thought so ?)
Dealer reckons that the alarm draws 0.25A/Hr when set, so on a 45A battery as fitted to RAV4 VVTi, it takes 6A a day so if the car is not used for a number of days, the drain will be sufficient to stop it starting the car. He reckons maybe I should not set the alarm but use the key to lock it instead of remote.
Dealer is not being unhelpful, but says there is nothing he can do re replacement while the official Toyota tests report battery is not faulty.

What do you guys reckon? is the Battery faulty (and the RAC tests are right)? Is it just the way the car sits unused for maybe 3-4 days at a time with the alarm not draining the battery and that is just the way it is?
I would have thought I could leave a car for a week, maybe 2 weeks and just jump in and start it up! is that so unreasonable :huh:



#4 shcm

shcm

    Top Rank Poster!

  • TOC Supporter Plus
  • 2,062 posts
  • First Name:shcm
  • Gender*:Not Telling
  • Toyota Model: The future is bright
  • Year: Non
  • Location: Other/NonUK

Posted 26 March 2008 - 01:04 PM

I agree with T600, 250mA (0.25A) is IMHO too high.

With the car locked up, most vehicle manufacturers are looking for a quiescent current (as we call it) in the 10's of mA region (say 10mA to 50mA i.e. 0.01A to 0.05A), but also as low as they can get and they have a nasty habit of making the specs lower as time goes by.

Having said that, with the car unlocked you'll probably see more current, as quite a lot of body controllers have a low power "sleep" state when the car is locked and will draw more current when they are "awake" - when the car is open. They obviously still monitor all the alarm inputs in the low power state, but, for example, these inputs will only get monitored (strobed) every so often, which, cutting a long story short, saves power. The strobe would be typically every 10 to 100 milliseconds or so.

Also, car batteries don't particularly like being fully discharged, I believe. They are more optimised to deliver the 200A or so for a couple of seconds, required to get the car started. Other lead acid batteries are more suited to a slow full discharge. I think is is all down to the plate design/thickness, but I'm by no means an expert on battery design. So, if the battery is being regularly deep discharged, due to a high vehicle quiescent current, it may be shortening its life too.

Cheers

#5 Hoovie

Hoovie

    I Like Cat Trees!

  • Banned
  • PipPipPipPipPipPipPipPip
  • 4,277 posts
  • First Name:David
  • Gender*:Male
  • Year: 2013
  • Location: Berwickshire

Posted 26 March 2008 - 01:59 PM

Thanks for replies - much appreciated :thumbsup:

I am not convinced about a 0.25A draw being normal I have to say.
I have turned off both interior lights now so they don't come on at all. Car is very standard electrics-wise except for towbar wiring and an iPod interface jobby, but on the current drain tests carried out, there is nothing out the ordinary happening according to the tests.

I have asked the dealer to make sure that my battery probs are recorded on the system as the car is 3 years old in May and I don't want them to turn round in June and say "yup, it is faulty - but not in warranty anymore - give us money to fix".
I cannot get over the fact that car doesn't like to left for a few days now, but before the new year, had no probs with this battery - and in fact I did leave my car in a Heathrow T4 carpark (renowned for setting alarms off by that terminal) for 10 days just before Xmas 2007 and it started fine when I got back to it, so if ok then, why not now :dontgetit:

Been looking on eBay at those Solar Panel trickle chargers that you plug into the cigar lighter - cost about £12.50 inc postage

" This is a brand-new Solar Powered Battery Charger with Power Cable. It can keep your battery topped up with solar power, compatible with cars, van, boats, caravans, etc. With the cigarette lighter plug, you simply connect the unit to your vehicle cigarette lighter socket and the solar panel will convert the solar energy to trickle charge your vehicle’s 12V lead acid batteries with no additional running costs. You just expose the charger unit to the daylight and it will charge the battery automatically, even if the weather is overcast or dull. It includes built-in red flashing LED charge indicator. And it is easy plug-and-play. Grab it now!! "

Might be handy for cars left for a few days unused at a time. Anyone tried these?

#6 T600

T600

    Top Rank Poster!

  • Advanced Members
  • PipPipPipPipPipPipPipPip
  • 2,965 posts
  • Gender*:Male
  • Toyota Model: Auris T180, MR2 GT T-Bar
  • Location: Nottinghamshire

Posted 26 March 2008 - 02:07 PM

No keep meaning to try one; Maplin do one for £14.99 too.

I don't think it'll work on the cig lighter on a Toyota though as they're usually accessory circuit controlled; i.e. key needs to be in. You'll have to wire it in, or clip it to the battery terminals.

#7 Hoovie

Hoovie

    I Like Cat Trees!

  • Banned
  • PipPipPipPipPipPipPipPip
  • 4,277 posts
  • First Name:David
  • Gender*:Male
  • Year: 2013
  • Location: Berwickshire

Posted 26 March 2008 - 02:19 PM

No keep meaning to try one; Maplin do one for £14.99 too.

I don't think it'll work on the cig lighter on a Toyota though as they're usually accessory circuit controlled; i.e. key needs to be in. You'll have to wire it in, or clip it to the battery terminals.

I was wondering about that actually - As the cigar lighter is off when ignition off, then I can't see it working "as it" - simple enough job to add in a little circuit for one of these, though - and cheap enough to try out. :D

#8 bothwell_buyer

bothwell_buyer

    Top Rank Poster!

  • TOC Supporter
  • 7,895 posts
  • First Name:Ian
  • Gender*:Male
  • Toyota Model: RAV4s, MR2s
  • Year: 1994
  • Location: Lanarkshire

Posted 26 March 2008 - 02:58 PM

Oh dearie me (or words to that effect).

Car batteries come in all shapes and sizes - and in 3 or 4 different capacities. Just after buying a hefty battery for my landrover although the previous one was just struggling - not knackered.

The standard RAV battery as fitted by Mr T to the 1994 RAV4 petrol was wholly inadequate for purpose and it was lucky if it lasted 3 years. Aside of this, it is one of the smallest batteries - I've got a larger battery fitted to my 10hp diesel generator!

Lesson 1 - Current useage will be on alarm; clock, and other residual monotoring currents - whether or not you lock with key or with alarm on. Anchorman has described in the past (I think it was him cos he knows about battery powered trainsets) about drop testing batteries. Any garage can do it, or AA or RAC. The AA have a contract with the same co I use for replacing batteries....its not unusual to replace a battery - but I'd say 2-3 years use minimum unless as has been said its been left to go completely flat in which case save up.

Lesson 2 - the alternator should provide enough to recharge the battery quite quickly unless you have an array of mega watt lights like mine. (You don't).

Lesson 3 - has alternator output been checked? An auto-electrician can do that or use a multimeter.

And 4 - sometimes a faulty starter motor will flatten the battery on start up...unusual for such a young car - do you let go of the iginition key once engine has started?

After that, its checking current drain whilst car is running - doesn't take much if a wire is grounding with a resistance within the fuse rating.

Plugging into cigar lighter - sorry - might work on a landrover

As has been said, you can get battery chargers. Classic car enthusiasts (like wot I try to be) use a trickle charger as their cars are often garaged over winter. These keep the battery in good condition.

It looks as if the battery fitted last year was a 1 year guarantee jobbie and thats what you got - 1 year. The dieselly RAVs need a heavier battery but you should be getting 3 years out of your battery.


Me and the landrover - well apart from a faulty earth lead connection to the engine, I reckon the starter is knackered - but I can't start the beast to take it up to the local guys who renovate and fit starters and alternators and now its snowing/raining and I spent all morning trying to return a lighting genny set which had its brakes locked on so we have a long black line up the street and my hands are filthy, sore and no wonder I drink....went up to my favourite local chippy van for curry and chips and there's cameras everywhere - so i ask whats going on and got told that Mel Gibson is making a film about a donkey so I take 6 valium and return home!

#9 Hoovie

Hoovie

    I Like Cat Trees!

  • Banned
  • PipPipPipPipPipPipPipPip
  • 4,277 posts
  • First Name:David
  • Gender*:Male
  • Year: 2013
  • Location: Berwickshire

Posted 26 March 2008 - 04:09 PM

Car is a "starts on a key turn" one - no churning needed (so yes, I do let go of the key :huh: ). Car is parked outside so don't really want to (and should not need to) have a trickle charger plugged in with a lead trailing around outside.

I haven't done any specific testing myself as as far as I am concerned, car is still under a full warranty and they should sort it out. I could put my fluke DMM to check the drain, but would mean arsing around with disconnecting and connecting batterie, etc - and is something the garage should be doing, not the customer (as they should be sorting under warranty)
The service manager is in full agreement with you re battery - undersized for car. Replacement is a Toyota badged one - I don't know why they have to skimp and don;t just fit the same - diesel style - battery to all the RAVs

#10 anchorman

anchorman

    Top Rank Poster!

  • Registered Member
  • PipPipPipPipPipPipPipPip
  • 10,794 posts
  • First Name:Don
  • Gender*:Male
  • Toyota Model: RAV 4 SR 2.2 D4D 150 in Decuma Grey and Daihatsu Sirion 2008 with Yaris mechanics.
  • Year: 2012
  • Location: Derbyshire

Posted 26 March 2008 - 05:03 PM

Toyota spec for acceptable or typical drain is 0.020 amps and they reckon anything above 0.035 amps is unacceptable (ties in nicely with shcm's comments).

I think bothy makes a lot of sense (its a pity the chippy van was busy as he'll hit the drink again now!) in saying that you could do something far more productive with your money than buy a trickle charger - that takes care of the effect but not the cause. I think a cheap multi-meter would be a better investment. If you set it to DC volts and measure the voltage when the engine is running it should rise up from 11 - 12 volts to about 15 volts. That is a very basic but nontheless effective way of summarising that the charging is OK. If you then disconnect the earth lead and set the meter to amps you can check the above values by connecting the meter between the battery and the disconnected lead. If they are high then you have to start testing all the circuits to see which one the draw is going to but unless you are fairly competent you should leave that to an auto electrician.

Toyota also recommend that you check for a discharge accross the battery casing. For this you connect the voltmeter to the connected earth lead and the other test lead to the battery lid. It sounds strange but you can get a significant drain if the top of the battery is damp or dirty. The reading should be less than 0.5v and if it is higher use baking soda and warm water to clean the battery lid.

Now having said all this a fully qualified electrician will not do anything until he has drop tested the battery. This probably what the AA man is doing but the trouble is that you cannot drop test a battery until it has been fully trickle charged or it will give you duff results (it will tell you it is knackered even if it isn't). There are far more sophisticated testers that can test a battery when it is discharged but these are very expensive and normally not justified to a DIYer. If this is what Toyota are using to test your battery then they will have more representative results.

I know it is in the hands of the dealer but I would still do a bit of testing as each time it fails to start it is you that has to put up with it.

Bothy - you know if that LR starts it will frighten you and it will also fog out the south west of scotland so its probably better left as it is. Are you sure the paps weren't after pics of you for OK mag? "Bothy hits the petro chemicals after chippy van tantrum". Money is good according to Kerry!

Have something to contribute?

Sign in or register to start a topic...


Not what you're looking for?

Register now, we have a huge community of enthusiasts to answer any questions you might have



0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users