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How Long Should A Battery Hold Its Charge For?


Hoovie
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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:

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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.

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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:

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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

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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?

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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.

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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

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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!

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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 !Removed! 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

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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!

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Ma fug is a mixture of oil and steam ah reckon. The LR willnae turn its starter altho theres a braw smell comes aff the Battery lead insulaion - so its oot wi the Fluke multimeter and check earth continuity then the current drain on the glo plugs n then starter.

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I guess I will do some testing then - I won't bother investing in a cheap multimeter - I'll use my expensive (at the time) Fluke DMM instead ;)

I did 300+ miles yesterday, so if the Battery is not fully charged now, there is definately something wrong!

Thanks for the step-by-step suggestions, Anchorman - much appreciated. I used to work in electronic and electrical engineering (hence the fluke) but not really done anything with cars, so I reckon I should be able to follow your suggestions.

I'll post back the findings :thumbsup:

One last thing - where did you get the Toyota Spec for current drain from? I may need to quote that back at them!

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Voltage Readings:

Initial Battery Voltage: 12.47V (Car unused today, driven 300+ miles yesterday)

Putting some load on (fan, HRW, radio, lights) WITHOUT starting engine: Battery Voltage dropped with each load as expected, going down to about 11.70V

Battery dropped to minimum of 9.96V while starting car, and raised to 14.36V when idling

Adding load while car was idling cause voltage to dip and then come back up to around 14.3V - presumably as alternator kicks in more.

Voltage differential between battery Earth teminal and battery lid - highest differential I could obtain was 1mV - so that looks very healthy.

I will do the current tests at the weekend :)

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That is OK for terminal voltage but the real test comes with some heavier discharge stuff. pm me with your email address hoovie and I will send you the pdf file.

Regards

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This was a common complaint and the answer for people leaving their cars in excess of 5 days at a time was to fit a diesel Rav Battery but Toyota CRC would not pay for the upgrade

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just for interest, I've had problems with the LR starting - fitted a new 80amphr Battery and still problems...went to starter motor engineering place who diagnosed Battery duff.

However, I wasn't convinced. Have returned Battery and will get new one delivered today - Lucas 80AH

After lots of voltage measuring etc, previously, I'd ordered a new set of quick release battery terminal clamps. Arrived yesterday so fitted them in afternoon. Put in a newly charged quite new 60AH battery and hey presto - the LR started!

The problem was corrosion on the earth terminal clamp - although it showed no resistance on no load/light load (0.00 ohms), on starting load (up to 350 amps approx) the high load wouldn't flow through the corroded connection and heat was produced with no starter turning.

Moral of this is to make sure you have the battery terminals nice and clean then grease them when fitted. I thought they were clean buy close inspection showed the brass (in this case) connector was corroded/oxidised.

Cost of repair = £3.00

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Hello Hoovie, sounds like your Battery problems are causing you upset :( , first off i have the same engine in my 3 door RAV4 and last year i only done around 1300 miles :o , it could be left for over a month without being used and always started on the button.

The Battery lasted the 3 year warranty almost to the day :angry: and in January 2006 i fitted a heavy duty aftermarket Battery, this has been as good as gold as I've used the RAV4 even less since then :rolleyes:

As an ex -mechanic can i offer a little help, my guess is you battery is f**ked but you need to be sure by checking the charge rate, this best covers how to do that.....

http://www.autoelectro.co.uk/bulletins/AE%...bulletin-08.pdf

It can be a bit of what comes first.... the egg or the chicken, as you need a good battery to get a good charge reading, this would be best done after a run out in you RAV4, with the engine running, turn on everything electrical and with a volt meter across the battery ( engine revs raise to around 2000 RPM ) you should be getting a reading of around 14.5 v.

If you are getting that reading may i suggest you give up with the dealer and go buy yourself an aftermarket battery with a 3 or 4 year warranty , that way you can start enjoying your RAV4 again and not worry if its going to start every morning.

Battery choices are Halfords or one from a motor factors, just make sure it has a long warranty , good luck :)

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This was a common complaint and the answer for people leaving their cars in excess of 5 days at a time was to fit a diesel Rav battery but Toyota CRC would not pay for the upgrade

I have a 2005 XT5 2.0D-4D Diesel and I have had starting problems after leaving it for two weeks several times during the three years from new! After one year they gave me a new Battery - no improvement. the RAV has been checked a few times by the dealer - everything ok!!

How can a large company like Toyota persist in not solving this problem?

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This was a common complaint and the answer for people leaving their cars in excess of 5 days at a time was to fit a diesel Rav battery but Toyota CRC would not pay for the upgrade

I have a 2005 XT5 2.0D-4D Diesel and I have had starting problems after leaving it for two weeks several times during the three years from new! After one year they gave me a new Battery - no improvement. the RAV has been checked a few times by the dealer - everything ok!!

How can a large company like Toyota persist in not solving this problem?

Sounds a bit unusual - dya know what amphours the Battery is? It might be on the top or side label. (AH)

Got my replacement Battery for the landrover today - a 90AH beast. Almost a 2 handed job to lift it!! The battery that came out the LR was for a HGV!!

I don't have a problem with the existing battery in the RAV 4.1 but am tempted to look at the feasibility of fitting it in the rear...it would be better up front as a heavier battery to keep the nose from lifting off on accelerating tho. The space is just a bit tight - maybe extend it into the glovebox??

And great news - the rear anti-roll bar arrived from the USA today. We'll try it on RAV number 2 first as that still has the custom exhaust to be manufactured/fitted. If it works, then will order another for RAV number 1.

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Hoovie's readings look plausible ones for a fully-charged Battery and I should go along with what others have been saying (like Anchorman, I suspect the figure for the residual drain at least has the decimal point out by one place).

The news about modern batteries is both good and bad: the good news is that they are more efficient and much lighter for the job in hand and you are not wasting fuel dragging round excessive quantities of lead. The bad news seems to be that these smaller batteries do not hold their charge for anywhere near as long and some modern ignition systems (I do not know if the RAV one is such a system, but I suspect it is) do not put up a struggle to start with lower voltages like one of my old cars — they just do not want to play and sulk.

Living as I do dividing my time between the two extremes of the nations and having far too many cars, I can report that all the old ones with 75+Amp-hour batteries start without problems when left for a month or so without being used, whereas, thus far, the experience of my RAV and another modern car of my wife is that a fortnight is pushing it. When fully charged, the batteries in each do their stuff, give a positive reading on a deep discharge test, and work just fine if the car is driven every couple of days, otherwise, out with the trickle charger.

George

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Looks like conclusion is basically "Everything is as it should be and as designed, but a bit of a borderline design to start with"

Think I will check the current drain just to complete the diagnosis and when/if I have to replace the Battery, get one with a decent rating

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Get yourself a C-Tek conditioner / charger.

They're about half the price of a decent Battery (£40) and will keep your car topped up and get the best life out of your Battery. I'm sure there are other savings too; a Battery that's low in charge is being recharged when you drive at the expense of mpg. Whereas charging the battery from the mains costs next to nothing.

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I'd thoroughly recommend some sort of long-use charger for keeping a Battery in tip-top condition. I use a Deltran Battery Tender for my bike batteries; you can leave it on all winter (the older bike doesn't go out when it's cold/wet/snowing/inclement, so it's basically laid up for the winter months) and it keeps the Battery completely fresh, and deals with the small but significant-over-time drain caused by the alarm. I've had the old bike for seven years and it's still on the same battery it had when I bought it, without any problems. In fact, I was cruising around on it earlier today :ph34r:

P3170352_01.jpg

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I have a Battery cut off on my supra......

e630_1.JPG

...but i guess thats not possible on a modern vehicles electrical system, i can leave the Supra for a few months, twist the cut off switch and she starts on the button.

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