When Parked Up How Long Should The Battery Stay Charged ?

[troy45]

£40 for a halfords battery charger. A must for any car owner

£40 minus 15% in some cases ;)

[Justin Smith]

I have battery chargers both at home and at work, that`s not the issue. The problem is the battery going flat when the car is just parked. Are we really is the ridiculous situation that I have to use the car (when it`s more convenient not to* ) just so the bleedin` battery doesn`t go flat ! I never had this problem with my previous car, a Ford Escort.

* The car is sometimes needed at work and I can walk to from home in little longer than it takes to drive (apart from on Saturday mornings.....). To be frank I no longer actually like driving, particularly through peak hour traffic. My wife has a Yaris at home which is more economical and easier to park than the Focus. Thus most of the time we just use that, apart from long trips where we need more room for our toddlers stuff.

[madmole]

But if your battery has gone flat in the past its no longer viable or holding a full charge. so it will last far less than normal now. Lead acid batteries are damaged by going under 40% charge. its hard to get that capacity back

Mine goes a week no problem, not had it long enough to know what happens if left longer. maybe you just need a new battery

[artscot79]

Focus doesnt use lead acid batteries due to the smart charge it uses double or silver calcium which are more resistant taking a higher charge 14.4 volts when the electrolytes cold

[madmole]

In UK they are Flood Fill Lead Acid 75 ah fitted as standard in MK3 due to the stop start. That's what in mine from Sept 2013

[artscot79]

a 2006 climate ti vct which is what he has wont it has a silver calcium battery and as such Most
ordinary

Lead
Acid batteries degrade quickly in performance if not kept
fully charged. This can happen if your vehicle is used
infrequently / less than once a week. A battery charger /
maintenance unit will keep your battery healthy for a lot longer!
Many manufacturers refuse to honor the guarantee if a lead acid
battery hasn't been used / kept topped up frequently enough!

Ordinary Lead Acid batteries which the focus doesnt have ........
such as car batteries need to be regularly charged and kept topped up
by the
vehicle alternator to keep them working properly. If, for any
reason
the battery's energy levels fall below a certain amount and stay there
for prolonged periods of time - it will become unreliable. in a silver calcium battery this happening too often will prevent the battery from holding a full charge

[Guest]

It is what it is and if I'm you I would invest in a battery charger, jump pack & jump leads.

[Justin Smith]

I fitted a new battery after this problem first emerged, it`s a "Calcium" (whatever that means) Halfords HCB063 (46AH) with a 4 year warranty. It`s the one recommended by Halfords, so if it`s unsuitable and keeps knackering itself up I shall just keep having it swapped ! Having said that when it last went flat I fully charged it then drop tested it and it seemed fine.

I like the idea of using a solar charger to keep the battery charged up but the fact that it may not work if connected to the "cigarette lighter" rather complicates matters. Are we sure it won`t work doing that ?

I am tempted to suggest that if Ford know that batteries will go flat on their cars if left for just 2 weeks they should install a solar trickle charger as standard (or a separate starter battery).....

I always keep a set of jump leads in my cars !

[madmole]

Test your ciggy lighter, is it still live after the ignition is off?

Does it stay live after a time

Older cars normally had a ciggy socket that was permanently live or ignition fed. All my fords up until his one had ignition fed ciggy lighters, but when they stopped calling them that and calling them power sockets many cars moved to permanently on. I know the MK3's is under can bus control and doesnt turn off with the igition but at some time later when the battery management decides to minimise draw

leave you car for a couple of hours then just go and plug something in or test with a voltmeter

[Justin Smith]

So we`re saying that if I plug something into the cigarette lighter and it works with the ignition off then that means that putting a charger onto it (i.e. current going in the opposite direction) would work ?

I`ve just gone and checked it. It`s been parked up about 6 hours. I plugged in a meter charging lead and the charge light came on the meter. But it hasn`t got some kind of fancy system where it turns on the power to the CL when the central locking is opened has it ? ! ?

[madmole]

Yes, I think its only the MK3 that is clever enough to turn it off at some later time

Mk1 and 2 its either on all the time, or only on when the ignition is on

So if its live after the ignition is off you are safe to assume its permanently live (unless its a mk3) and can plug a charger in

[Justin Smith]

I take it my Focus is a Mk2 ? The original Focus being the Mk1, mine being a Mk2, and the current model a Mk3 ?

There was once a time when Ford only called the next model a new Mark if it was a completely new model, but that went out of the window with the so called Mk5 Cortina which was really just an updated Mk4 ! After that I just got confused with all this MkX business, not that it`s any where near as bad as the "Football League Championship" (which is actually the Second division....)

[Justin Smith]

I`ve been using an Oxford Solariser (solar charger) and my Focus started fine after being left for 17 days, it might even have been 3 weeks but I can`t remember for sure when I parked it up at work ? ! ?

I messed about a bit with a couple of voltmeters and the "Solariser" and was a bit concerned to see that in overcast conditions (but at midday, not dusk ! ) it was only giving out about 6V ! That is to say it wouldn`t actually be charging the battery at all, to do so would require it to produce at least 12.5V. My conclusion is that particularly in the winter it can`t be putting that much charge into the battery, possibly 4 or 5 hours a day on average ? And that`s at a maximum quoted current of 80 to 100mA !

Has anyone else had experience with solar battery chargers ?

[madmole]

Yes, Had my landrover with solar cells on the roof rack for several years

You need around 4m2 of cells (around 160W) to guarantee you'll be putting a useful charge in in overcast or winter conditions.

So those little 8W chargers on the dash are totally useless unless its a bright sunny day

Unfortunately its mid winter when the battery needs the help

[jeebowhite]

To be honest when the car is switched off its running so little that unless you have a parasitic drain, any help is beneficial, even if your only trickling 6v in that is still boosting the battery enough that the voltage used for immobiliser and sensors is being topped up. It might not be putting out alternator strength but it will still be doing you a favour.

[Justin Smith]

To be honest when the car is switched off its running so little that unless you have a parasitic drain, any help is beneficial, even if your only trickling 6v in that is still boosting the battery enough that the voltage used for immobiliser and sensors is being topped up. It might not be putting out alternator strength but it will still be doing you a favour.

How can putting 6V into a 12V (actually 12.5V) battery charge it up ? ! ? I didn`t think that was possible, in fact if the charging device didn`t have a diode in its output wouldn`t the battery discharge through the charger ?

[Justin Smith]

Yes, Had my landrover with solar cells on the roof rack for several years

You need around 4m2 of cells (around 160W) to guarantee you'll be putting a useful charge in in overcast or winter conditions.

So those little 8W chargers on the dash are totally useless unless its a bright sunny day

Unfortunately its mid winter when the battery needs the help

To be frank I did a few calculations based on 80mA output for all daylight hours (now found to be overly optimistic....) and even then I reckoned the battery would still discharge over time, it`d just take longer. I estimated 3 weeks rather than the 2 weeks it seemed to be taking !

[madmole]

Yes, has to be over the battery voltage to open up the diode, so 6v wont do a thing

Also if your car is parked near a radio site it cant always fully shut to power saving mode. I live near Heathrow airport and often see flat batteries. The Radar keeps cars remote door sensors from shutting down fully.

Also any dirt etc around the terminals can also allow a parasitic drain

[jeebowhite]

I may be mistaken but I thought that was the point of a trickle charger? To keep trickling a small charge into the battery, rather than honking alternator voltage through it all the time? Happy to admit I'm wrong if I am, but 6v might not stop the battery draining over the course of months on end, but it should slow down the loss to elongate it's chances.

For any car left standing for periods of time the battery ideally should be disconnected to prevent parasitic drain from killing it and a charger to keep something going on to keep it good.

[madmole]

Trickle charger is still 13.5+v, its just a very low current

Modern maintenance chargers can be left connected to a battery still in the car for long periods, they will not overcharge it

Disconnecting the battery on modern vehicles is a no no unless absolutely necessary (ie replacement). The electrics monitors charge in and out and many systems need keep alive voltage. If you disconnect and replace, you loose the history on the charging cycle on the battery and the ECU's ability to calculate age and efficiency etc

[Dales]

My ST has actually lay up in the garage for up to a month at a time without being used. Can go out press the start button and boom. burst into life without a problem.

I think its still the original Ford battery in the car too. Infact last winter it lay in the garage about 5 possibly 6 weeks and it didn't have a problem starting.

[Justin Smith]

My ST has actually lay up in the garage for up to a month at a time without being used. Can go out press the start button and boom. burst into life without a problem.

I think its still the original Ford battery in the car too. In fact last winter it lay in the garage about 5 possibly 6 weeks and it didn't have a problem starting.

Interesting........ I can only say I originally thought it unlikely that anyone could be stupid enough to design a car which flattened the battery after 2 or 3 weeks just being left stood, but I was told from so many different sources that was in fact "normal" that I took it as correct ! So I`d be interested to know how you get 5 or 6 weeks out of your car`s battery!

My wife`s old Fiesta had a Motorcraft (that`s Ford isn`t it ? ) and that lasted forever. I use to buy my batteries from Halfords with a four year warranty and they`d nearly always fail at four and half to five years old ! Can we assume that Motorcraft batteries are better than Halfords ones ? ! ?

[jeebowhite]

Batteries are not the issue, even on a proper sleep cycle the battery should use no more than 0.1 amps at any time, it's only if you have an issue and a system doesn't shut down properly. For example my cmax before me had problems where the trip computer wouldn't shut off that meant the battery never lasted 8 days without use it would flatten the battery, yet the mondeo had stood for 2 weeks earlier this year with no issue, having said that I have never left a car unused beyond 2 weeks, though I suspect in summer if I did leave the car for 6 unaided it would be easily startes

[jeebowhite]

Any battery is better than Halfords lol, I believe Bosch have a five year guarantee

[Justin Smith]

Batteries are not the issue, even on a proper sleep cycle the battery should use no more than 0.1 amps at any time, it's only if you have an issue and a system doesn't shut down properly. For example my cmax before me had problems where the trip computer wouldn't shut off that meant the battery never lasted 8 days without use it would flatten the battery, yet the mondeo had stood for 2 weeks earlier this year with no issue, having said that I have never left a car unused beyond 2 weeks, though I suspect in summer if I did leave the car for 6 unaided it would be easily startes

Can we just confirm something J. Are you saying any car where the battery flattens in 2 to 3 weeks has a fault ? Because that`s what I thought but am being told it`s normal from many different sources. The latest was when we picked up the car at APH airport parking in Manchester, I laughingly warned the chap we might need to jump start the car because the battery goes flat after two weeks or so, and he said that was very common for modern cars. As it happens the Focus started straight away because it`d only been stood for 11 days and the solar charger probably helped a bit, but the point is yet another person who should know was telling me modern cars batteries go flat relatively quickly.