Flat Battery

[blimeyme]

Hi Folks, been searching battery threads but cannot find one suitable so am looking to pull on your experiences.
My battery has been flat the last 2 times I have been out to start the car after approx. 1 week. Seems to charge up ok after jump starting where it fires up first time. Had car for 14 months and never a problem before even if left longer.
I wondered if my boot light was staying on but I cannot even locate my boot light ( think it might have been removed at some time perhaps due to this problem ) but if you could tell me the location I can double check just to make sure I haven't had 'a moment'!!!
Courtesy lights go off when doors closed and stereo is defo off......any thoughts on what it might be...any pointers gladly received.
Many Thanks, P

[Fredjohn]

The switch for the boot light is attached to the boot hinge on the (UK) driver's side. It can be operated by hand to see if the light is going off. But to check if it goes off when you close the boot lid, switch the video of your mobile phone to record, put it in the boot and close the lid. Open the lid then watch the video: you'll soon know if the light is staying on or not!!

You may have an old dying battery, so just buy a new one to the same size and spec: try Eurocarparts or any decent car accessory shop or even Halfords. Whether the battery is new or old, get a battery conditioner/charger and leave it plugged in whenever the car is not in use. The conditioners usually come with a fly lead arrangement. Attach it permanently to the battery and feed it to the side of the driver's seat where the seat belt is. You can then easily attach the conditioner when required. You can pay £50+ for a CTEK or £25 for a Halfords version : your choice.

Also check your alarm isn't draining the battery. Again a conditioner will solve this.

Hope this helps.

[lotusflasherman]

Boot light is on the top of that triangular bracket on the bulkhead directly forward of the boot lock - i.e. dead centre, up high pointing downwards. Mine doesn't come on as I've pulled the bullet connector just to make sure it never plays up.
If yours is not coming on so you can see where it is I would conclude it's not coming on so won't be the cause of the flat battery. You've considered most things apart from car alarm drain...

Next step I'd take is to disconnect a battery terminal and put a multimeter set to amps between the battery and the terminal connection to read what the current drain 'with everything switched off' is. Hopefully you'll have to switch to milliamps to get a reading. There is always some drain as the clock and radio feed to maintain the station presets are permanently live. Some radios and alarm systems can take a couple of hundred milliamps. 250 milliamps for a day is 6 amp.hours and the standard battery is 55AH. After a week that's taken 42AH so an old battery might struggle to get 250 amps of starting current out of what remains and after 2 weeks there's no chance. (Airport car park guys make a lot of money jump starting the '2 week stayers'.)

Though if you haven't replaced the battery for a few years it's probably that. Next option is take the battery to a Tyre & Battery dealer and get it tested. They'll put an ammeter with a low resistance, equivalent to the starter motor, across the terminals to check it can deliver the starting current required. Batteries left flat suffer from lead sulphate forming on the plates which prevents it delivering full starting current. Short journeys with starting current discharge followed by short recharge can also can sulfate. Nothing like regular extensive exercise for keeping fit ..

Lead acid starting batteries (as in cars) don't like being left on permanent trickle charge either. I've got a CTEK MXS 5.0 which is a battery monitoring charger which means it can be left permanently connected to electronically monitor the voltage but only starts charging when the volts drop to a particular limit. The MXS 5.0 also has a 'Reconditioning Programme' that does a deep discharge and recharge and it has made some batteries I was going to scrap suitable to keep using. I'd only use that as a last resort, not for routine maintenance of a battery.

[lotusflasherman]

You can pay £50+ for a CTEK or £25 for a Halfords version : your choice.

Comparing chalk and cheese ...

Technical spec' says it all:
CTEK will charge in amps whatever the type number is - e.g. my MXS 5.0 does 5 amps. Halfords sell the MXS 7.0 for £99.99 that does 7 amps at 13.6V. (All can be found cheaper on ebay)
www.ebay.co.uk/itm/CTEK-Multi-MXS-7-0-12V-Battery-Charger-replaces-XS7000-NEW-/302146593322?hash=item465957222a:g:wzgAAOSw4GVYNbvJ
Halfords 'Maintenance Charger' has output of 750mA, (3/4 of an amp) and no voltage monitoring circuitry so is permanent 'tickle' charge and, according to one review, seems to output at only 12V.

This is NOT a car battery charger.25 October 2016
Marius321
fromEdinburgh, UKAge Group: 35 - 44Gender: Male
I bought one 2 or 3 years ago, tried to use a few times on 2 different batteries.
It has same parameters. is. 6/12V and 750mA
Car battery at 12.2V is heavily discharged. Although they are called 12V batteries,
they are fully charged at 12.9V.
This charger seems to have output of 12V. For maintenance, it should have close to 12.9V
Car charger output should be at 14.4V and 3A.
This one at 12V and 750mA is not a car battery charger at all !!!
750mA might be so so for charging smartphones, not car batteries.
Halfords, you should know better! Very disappointed

www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/halfords-maintenance-charger

[Giniw]

Well I use a CTEK too but I have a question: do you all disconnect the battery to charge it?
I do, especially because of some of the steps (high tension pulses to do the desulfation, etc).
But I would be curious if anyone has interesting arguments ^^

[Fredjohn]

Can't argue with any of that Phil! Clearly 2 different bits of kit with more or less levels sophistication. Halfords do claim theirs switches from normal to maintenance charging automatically, but not sure if there's really any difference!

However I use 2 Halfords cheapos on my 2 cars and they successfully keep the batteries charged up, so I will continue to do so until they (the chargers) burn out. Then I may consider switching to a CTEK or equivalent.

PS I'd assumed blimeyme couldn't find the switch rather than the light, even though he said "light".

[dapinky]

My battery conditioner came from Lidls for not a lot of money, and has been on my car for a couple of years - never had a flat battery since then, and battery still good at last 'proper' test.

I also have a small solar panel which i keep connected during the Summer week of the year!

[lotusflasherman]

Can't argue with any of that Phil! Clearly 2 different bits of kit with more or less levels sophistication. Halfords do claim theirs switches from normal to maintenance charging automatically, but not sure if there's really any difference!

However I use 2 Halfords cheapos on my 2 cars and they successfully keep the batteries charged up, so I will continue to do so until they (the chargers) burn out. Then I may consider switching to a CTEK or equivalent.

PS I'd assumed blimeyme couldn't find the switch rather than the light, even though he said "light".

Constant trickle charge is not good for car batteries as once charged it starts to heat the electrolyte increasing sulfation but that Halfords charger's output is so low it just about compensates for drain from radio, clock and alarm etc and what's left is going to do 'not a lot' so no worries... But if you put that on a flat battery I think you'd die waiting for it to charge it to a usable condition - particularly with only 12V output! Start with a healthy battery & it might keep it that way so it's 'horses for courses'..

Dave, I bought a solar panel charger from a Club Lotus organised 'thing' at Donington a few decades ago. Paid quite a lot of money for the time (£25+) and found it did nothing. Found out why with a multimeter - on the sunniest day at 90°to the sun output was 10.2V. My first experience of 'the solar panel con trick' ! Think it may have been a duffer!

[Rambo]

Just out of interest, I recently replaced my original CTEK 0.8A battery conditioner (the old one appears to have given up after >10 years use) with a brand new CT-XS 0.8, CTEK 12v 0.8A battery charger. It appears to be a lot more sophisticated than my old one and has a 6 stage process including desulphation.

Multi-step fully automated charging cycle
1, Desulphation/recovery: To recover where possible weak or sulphated batteries.
2, Bulk charge: A constant current charge at 0.8A until the battery reaches 14.4v. When complete the battery will be approximately 80% charged.
3, Absorption charge: A constant voltage charge at 14.4v to complete the charging process.
4, Test: A series of tests to confirm the battery is fully charged and retaining the charge.
5, Float charge: A continuous float or trickle charge to maintain the full charge for a maximum of 10 days.
6, Pulse Maintanance Charge: An intermittent charge/test cycle to provide maximum battery life. Keep the battery at or close to full charge indefinitely without over-charging.

Cheapest I could find was £40 Inc p and p from MDS Battery Ltd (http://www.mdsbattery.co.uk)

[lotusflasherman]

Just out of interest, I recently replaced my original CTEK 0.8A battery conditioner (the old one appears to have given up after >10 years use) with a brand new CT-XS 0.8, CTEK 12v 0.8A battery charger. It appears to be a lot more sophisticated than my old one and has a 6 stage process including desulphation.

Multi-step fully automated charging cycle
1, Desulphation/recovery: To recover where possible weak or sulphated batteries.
2, Bulk charge: A constant current charge at 0.8A until the battery reaches 14.4v. When complete the battery will be approximately 80% charged.
3, Absorption charge: A constant voltage charge at 14.4v to complete the charging process.
4, Test: A series of tests to confirm the battery is fully charged and retaining the charge.
5, Float charge: A continuous float or trickle charge to maintain the full charge for a maximum of 10 days.
6, Pulse Maintanance Charge: An intermittent charge/test cycle to provide maximum battery life. Keep the battery at or close to full charge indefinitely without over-charging.

Cheapest I could find was £40 Inc p and p from MDS Battery Ltd (http://www.mdsbattery.co.uk)

The CTEK XS0.8 is for batteries up to 32AH so really a motorcycle battery charger. Might be a bit slow dealing with 55AH Elan battery that's gone down but see no reason why it won't keep a good un' charged.
MXS 3.8 is best for batteries up to 85AH and one of those lives in my lockup on the SE on SORN but it doesn't have the Reconditioning program.
MXS 5.0 has, so stays in my garage at home and does everything I need on all the batteries.

Also CTEK has great range of extension leads and sockets to permanently install. Both SE's have this socket with 'traffic light' LED to indicate battery volts installed where the switch blanks were. Useful to know if it needs a top up if not used for several days. (LED's only flash every couple of seconds so not caught one on when photo taken.)

ctek1.jpg

ctek2.jpg

By the way - good spot on MDS I get laptop and instrument batteries from them but never thought to look for CTEK there. Don't think they sell via ebay.

[Rambo]

You're right Phil. The XS 0.8A is struggling (phases 2 and 3 - bulk and absorption charges) a bit to get up to the 6th phase which makes me think that the battery on my black SE has seen better days. Must check my records to see when it was last changed

I will swap over the new battery from my NMY SE on to the black one and see how quickly it gets to the 6th stage

I had no problems with my old 0.8A CTEK conditioner, but maybe my batteries were in better nick ?

For anyone else wanting a battery conditioner/charger, I too would recommend getting the CTEK XS 3.8A or 5.0A

[epipete]

I had a solar panel charger thingy until last week, it worked great and kept the battery always ready. Sadly, I put it on the drivers seat and forgot when later I went to close the roof (my door lights don't work - something else to sort out!!!

[John_W]

Blimeyme,
There's a thread about batteries here.

Apparently the original was an AC Delco 842, which may still be available from an AC Delco agent. When mine died last year (after 14 years) I just replaced it with a Halfords HCB075 (with a 4 year guarantee) for the princely sum of £79. The key dimensions are: length 24.2cm, depth 17.5cm, height 17.5cm. Some people (M100TWO, Monty) say that they have fitted batteries that are 19cm high. Just find one with the correct dimensions and connection posts and choose the amp-hour rating and battery technology you want. Mine is 60ah.

To keep it charged, I (like everybody above) use a battery conditioner, My car spends the winter in the garage, permanently connected to the battery conditioner. I used to have a CTEK, which worked OK for a year or two before it went pop. On disassembling it, I found that a capacitor had exploded and spread goo and scorch marks over the interior. I then bought an Optimate (with the charge/float/test/top-up cycle, including desulphating which has recovered deeply discharged batteries for me on a few occasions - lawn mower batteries) that worked fine for 12 years until last week when it stopped working. I have replaced it with a CTEK MXS5, as Optimate have changed their range and I couldn't find one with features I wanted for a price I wanted to pay. Let's hope that the CTEK lasts longer than its predecessor.

Oh, and my battery won't last two weeks if not used or charged. Never has done.

John

[blimeyme]

Many thanks all for Sharing your knowledge and experience with this problem, very much appreciated. Gives me some good direction.
Cheers again, P

[tb10]

I use a Battery Brain in my cars which remotely isolates the battery and prevents any drain but also reduces any potential for theft as the battery is isolated when the unit is activated. The only risk I have seen previously is that the headlights pop up when the power is restored and I have previously blown the headlight module in one of the cars

If you don't activate it by remote control it also automatically isolates the battery if the voltage falls below 12v so you should never be stranded unless theres a clear discharge issue with the battery.

See here

regards

John

[simonbuk]

I think I now realise why I found my boot light wiring disconnected a month or so back..............this was just before I drove it down to my garage to be parked up for a little while..............now finding out that my battery is flat.

I wish I hadn't reconnected it.

B0ll0cks.

[Rusty Wishbone]

I think I now realise why I found my boot light wiring disconnected a month or so back..............this was just before I drove it down to my garage to be parked up for a little while..............now finding out that my battery is flat.

I wish I hadn't reconnected it.

I had exactly the same set of events in the last couple of weeks. It was just as well that I checked the state of the battery last Sunday so that I could recharge the battery and disconnect the boot light before my journey to work on Monday.

[MPx]

Slightly different tack on this. I've been suffering from an electrical drain for some time. Done the usual checks for boot light etc. Asked the guys at SWLC to look at it for me when in for MOT and fettle. They found the radio when "off" was still drawing 0.7amps - which is why my Optimate was failing to keep up! That seems a lot of electrikery to remember the code and a few presets! Current solution is to remove the permanent feed - so I can still use it if I want but just with a bit more ag, and at least I can use the car when I want as well!