Motoring Discussion > A very flat battery	Miscellaneous
Thread Author: Iffy	Replies: 47

New Sun 27 Feb 11 09:31   A very flat battery - Iffy

I somehow managed to leave the keys in the CC3 for a few days which flattened the battery. The car was securely parked, but getting it started again proved less than straightforward. My first plan was to use my recently purchased Lidl charger, but the damn thing wouldn't work, despite the standby light coming on. Plan B: call the AA. "No problem, sir, all our patrols are busy, but we will send a local garage within the hour." Local garage turns up in the longest flatbed recovery truck I've ever seen. My car is in the back yard, but the truck is too long to get around the bend into the back lane. The bin wagon and a fire engine can get round, but the recovery truck could not. Another hour passes as I wait for the garage to send a smaller wagon. This turns up, and the guy tries to jump the CC3 with a booster pack. Waste of time, not enough grunt. So he puts on jump leads from his wagon, via a plug in the bumper. Again, it wouldn't start. The engine turned over, but the dashboard lights flashed rapidly, which I think was the car telling us there was not enough power. The man tried using the booster pack and the jump leads, but again it was no go. At my suggestion, we left if for a few minutes in an attempt to put some charge in the battery. After doing that, the car fired up first time. Seems to me a diesel with an absolutely dead flat battery takes some starting. And the battery really was flat - the radio demanded its code as if it had been disconnected. I took the car for 30 mile run in daylight yesterday and the car is now starting normally. Out of an abundance of caution, I'll go for another lights off drive today. Reply to this message | Report message

New Sun 27 Feb 11 09:37   A very flat battery - Old Navy

Your LIDL charger will probably work now that there is some life in the battery, I think they need about 7V in the battery to work. Better than burning diesel just to charge it. Last edited by: Old Navy on Sun 27 Feb 11 at 09:38 Reply to this message | Report message

New Sun 27 Feb 11 09:39   A very flat battery - Clk Sec

Yes. I'd charge the battery now, rather than taking the car for a spin. Reply to this message | Report message

New Sun 27 Feb 11 09:42   A very flat battery - Iffy

...Your LIDL charger will probably work now that there is some life in the battery... I wondered about that. Might give it a try, although I'm not sure if the thing is of much longterm use to me if it won't charge a flat battery. I think the electronics in the charger might be too clever for their own good. Might be better off with a simple one that just gives out a trickle irrespective of anything else. Reply to this message | Report message

New Sun 27 Feb 11 10:06   A very flat battery - -

Some Diesels can be difficult to jump start through leads whatever the back up source. It's not the power of the jump pack necessarily but the amount of current that the leads can carry. I always carried high quality leads and a jump pack in times gone by, but find something like a Transit or especially a Japanese 4x4 Diesel absolutely flat and they would sometimes need three sets of leads to get them to turn over, yet my jump leads alone would start a completely flat 12 litre lorry engine no bother , work that one out. Surprised the jump pack didn't start your car to be honest though, was it a proper jobbie or one of those toys sold at accessory shops with built in compressors etc. Reply to this message | Report message

New Sun 27 Feb 11 10:09   A very flat battery - Zero

Agree with GB, its all down to the leads. I have a heavy duty pair, thick copper cored (not aluminium) crimped and soldered into heavy duty clamps that would cut your finger off. Heavy things and a real beech to try and coil up. Reply to this message | Report message

New Sun 27 Feb 11 10:20   A very flat battery - Iffy

...Surprised the jump pack didn't start your car to be honest though, was it a proper jobbie or one of those toys sold at accessory shops with built in compressors etc.... Looked like a proper one, although it wasn't very big. I agree leads are crucial, and I think the problem with the bumper plug-in power source is the leads have to be about three metres long. Having said that, it was 59-reg proper recovery truck, designed for the job. We used to use arc welder cable to make up a set of leads and jump from a commercial vehicle battery. I'm still surprised the car wouldn't start, the power we had turned the engine over fairly quickly, and I thought diesels were compression ignition. But there's no doubt charging my battery for a few minutes did the trick, so it was lack of power. Reply to this message | Report message

New Sun 27 Feb 11 10:27   A very flat battery - Zero

> >> I'm still surprised the car wouldn't start, the power we had turned the engine over >> fairly quickly, and I thought diesels were compression ignition. They are , but electronic injection. NO electrons, no injection, nothing to ignite. You had classic symptoms, all the power was going to turning the car over, pulling the voltage down, and modern cars do not like low voltage one teeny bit. The VW I had used to throw a complete fit, bringing on every warning light and buzzer in its armoury in protest, and it would bing and wink at you for up to 100 miles before it decided all was well again. Reply to this message | Report message

New Sun 27 Feb 11 10:44   A very flat battery - Iffy

...They are , but electronic injection. NO electrons, no injection, nothing to ignite... Makes sense. So could you tow start the car when it has a dead flat battery? No power used to spin the engine over, but some power produced by the spinning alternator. Reply to this message | Report message

New Sun 27 Feb 11 10:48   A very flat battery - -

>> No power used to spin the engine over, but some power produced by the spinning >> alternator. >> It's been tried in compounds and never works with a completely flat battery. Reply to this message | Report message

New Sun 27 Feb 11 11:27   A very flat battery - jc2

Not just Lidl chargers-our firm had a heavy duty charger/starter but it still needed an assist from another battery/charger if put on an absolutely flat battery-then no problem. Reply to this message | Report message

New Sun 27 Feb 11 11:51   A very flat battery - Iffy

...but it still needed an assist from another battery/charger if put on an absolutely flat battery... This is getting complicated. So how do I plan for this if it happens again? Buy a small battery and some cheap jump leads, keep that battery charged. When the car battery is dead flat, connect small battery to car battery with jump leads, and connect charger to one or the other in the hope some charge will reach the car battery. Alternatively, make sure breakdown cover includes home start. Or even better, don't leave the keys in the car. Reply to this message | Report message

New Sun 27 Feb 11 12:05   A very flat battery - Bellboy

recovery man wants a smack round the head for trying to start a fully flat modern ford with anything --------------other than getting some power into the flat battery first-- you have power control modules all over your car and they can easily fry first one to go is usually the immobilisor one built into the speedo you was very lucky Reply to this message | Report message

New Sun 27 Feb 11 12:24   A very flat battery - Iffy

...you was very lucky... Yes, I did wonder about that. I don't like jump starting any modern car, which was one of reasons I bought a battery charger. Having said that, there are jump start instructions in the handbook. Reply to this message | Report message

New Sun 27 Feb 11 12:41   A very flat battery - jc2

No problem for us-we had a large truck battery on a trolley complete with leads. Reply to this message | Report message

New Sun 27 Feb 11 12:47   A very flat battery - Iffy

...No problem for us-we had a large truck battery on a trolley complete with leads... Seem something similar used at car auctions. Reply to this message | Report message

New Sun 27 Feb 11 12:52   A very flat battery - Old Navy

I knew there was a reason that I give my battery a charge most weekends. The car is in the garage, no hassle to charge it while the car is not being used. Reply to this message | Report message

New Sun 27 Feb 11 13:15   A very flat battery - Iffy

ON, Looks like your were spot-on about the Lidl charger needing some volts in the battery. I've just connected it and the indicator lights now come on as they are supposed to. I'm still not overjoyed about having a battery charger that will not charge a dead flat battery, but I suppose it's better than not having a charger at all. Reply to this message | Report message

New Sun 27 Feb 11 13:40   A very flat battery - Old Navy

Most modern chargers are like this, I think it is a safety thing so that you can't short the leads. Reply to this message | Report message

New Sun 27 Feb 11 13:43   A very flat battery - Iffy

...I think it is a safety thing so that you can't short the leads... That's how we used to check if the charger was turned on. Kiss the the croc clips off each other to see if there is a spark. Reply to this message | Report message

New Sun 27 Feb 11 13:48   A very flat battery - Old Navy

>> That's how we used to check if the charger was turned on. >> >> Kiss the the croc clips off each other to see if there is a spark. >> >> Things have moved on from steam chargers, they now have electronicery and pretty lights for that. :-) These days chargers have to "know" that they are attached to a battery before they will work. Last edited by: Old Navy on Sun 27 Feb 11 at 13:50 Reply to this message | Report message

New Sun 27 Feb 11 13:49   A very flat battery - Tooslow

Well I bought one of these as I understand it will charge a completely flat battery. It's mostly used for charging the mower battery so I've had no need to test that capability, nor do I expect to. But I agree with Iffy's sentiment that I'd prefer to have a charger that can and I bought this in prererence to a cheaper CTEK model for that reason. www.amazon.co.uk/gp/product/B000RHWCNY/ref=oss_product John Reply to this message | Report message

New Sun 27 Feb 11 13:52   A very flat battery - Old Navy

That is an ALDI / LIDL charger with an expensive badge. Reply to this message | Report message

New Sun 27 Feb 11 13:54   A very flat battery - Tooslow

That's what you think :-) Mine is said to charge a COMPLETELY flat battery. Yours won't. And it was a Christmas present so it cost me nowt. John Last edited by: Tooslow on Sun 27 Feb 11 at 13:55 Reply to this message | Report message

New Sun 27 Feb 11 13:56   A very flat battery - -

Agreed Navy, i've got that CTEk and a Lidl's and whilst slightly different casings, the operation, switching and light sequencing is identical. Reply to this message | Report message

New Sun 27 Feb 11 14:00   A very flat battery - Bromptonaut

I've got a charger in the garage. Distress purchase from a spares shop in Golders Green c1982 after my recently acquired Mini went flat. Am we saying it will do stuff a fancy nre one won't Reply to this message | Report message

New Sun 27 Feb 11 14:03   A very flat battery - Tooslow

Depends whether you're comparing against the better CTEK models or cheapo LIDL models that they never have in stock anyway. :-) John Reply to this message | Report message

New Sun 27 Feb 11 14:12   A very flat battery - Injection Doc

Bell boys comments are spot on ! The recovery chap needs a slap. When a battery is dead flat no attempt should be made to start a vehicle with power pack or jump leads untill the battery has had suffiecent time to obtain some sort of recovery to stablise and balance the supply voltage. I think most vehicle handbooks tell you to connect leads and allow from a few mins to 1/4 hrs for the battery to recover. The possibility of frying electrics these days is huge. Avoid flat batterys at all costs. Most vehicle now have a relay that shuts the whole car down when battery voltage drops below 11.99 volts. My own landrover went to sleep the other day and had to call out landrover assist because the car was dead, but only because I had left it parked for 3 months in the garage without using it, battery voltage was ok but system had shut down to protect battery! Reply to this message | Report message

New Sun 27 Feb 11 14:08   A very flat battery - -

>> I've got a charger in the garage. The lads here put me right Brompton some years back (though in another place), i had a stone age jobbie too which would probably have lasted forever. However the old school charger like yours isn't regulated like these new smart chargers, and on a modern car with all it's sensitive electronics you should disconnect the battery before charging..which has it's own problems on modern cars. Picking up on something TS mentioned, that the CTEK will charge from flat..i think the Lidl's jobbie will do the same...i'm pretty sure both chargers have to be switched to the 'freezing' setting to enable from flat charging, though happy as ever to be put right. Reply to this message | Report message

New Sun 27 Feb 11 14:13   A very flat battery - Iffy

...i think the Lidl's jobbie will do the same... Mine won't charge from dead flat. I connected it, but the mode button did nothing. I connected the same charger to the charged battery, and the various mode lights lit up. The instruction manual is not very clear, but it says something about the charger detecting a voltage of plus or minus seven volts. In effect, if the battery is much under seven volts, it's no-go. Reply to this message | Report message

New Sun 27 Feb 11 16:41   A very flat battery - hawkeye

>> ...i think the Lidl's jobbie will do the same... >> >> Mine won't charge from dead flat. >> >> I connected it, but the mode button did nothing. >> >> I connected the same charger to the charged battery, and the various mode lights lit >> up. >> >> The instruction manual is not very clear, but it says something about the charger detecting >> a voltage of plus or minus seven volts. >> >> In effect, if the battery is much under seven volts, it's no-go. >> >> >> If it's the same as mine, it does 6v batteries as well. That means the software needs some means of categorising batteries so it knows which map to use as a charging regime. If the detected voltage is approx. 3.8 to 7.3v it thinks the battery is 6v, and below 3.8v it thinks the battery is unusable. It may then start pulse charging the battery to see if it will come back to life. All this takes a while and the LED display tells you nowt. The Aldi charger is similar but it tells you what it's doing via an LCD display. When all's said and done these little beasts only push out 4 amps or less so they aren't suitable for an immediate rescue. Depending on your budget, I'd get a cheap battery, leave the Lidl charger on it all the time and use some decent jump leads if you MUST leave your keys in the hole. Or just leave the charger connected if you are away. I swap (one of) my Aldi chargers between the 12v motorbike and the 6v bicycle and it's fine. The other one nurses the caravan battery. Reply to this message | Report message

New Sun 27 Feb 11 14:05   A very flat battery - Old Navy

My CTEK failed after about 18 months, I replaced it with an ALDI one, I also have a LIDL one permanently attached to a spare battery I use as a 12V supply in the garage. I could get two more for the price of a CTEK. Reply to this message | Report message

New Sun 27 Feb 11 14:08   A very flat battery - Tooslow

"My CTEK failed after about 18 months" You wore it out :-) John Reply to this message | Report message

New Sun 27 Feb 11 14:11   A very flat battery - Old Navy

Probably did, the mode button didn't mode any more. Its a cheapo charger in a fancy box. :-) Reply to this message | Report message

New Sun 27 Feb 11 14:13   A very flat battery - Tooslow

I did say "I bought this in preference to a cheaper CTEK model for that reason" :-) John Reply to this message | Report message

New Sun 27 Feb 11 14:18   A very flat battery - R.P.

but I suppose it's better than not having a charger at all. Should have splashed out a bit more on the Optimate - sort of an Mac version of everything else ! Wouldn't be without mine for the bikes. Reply to this message | Report message

New Sun 27 Feb 11 14:11   A very flat battery - Manatee

>> modern cars do not like low voltage one teeny bit. True. The alternator failed on the CRV last August. First I think the ABS light came on, followed at intervals by the airbag light, the VSA light, and the picture of an engine. The 'smart' chargers can be fooled by flat batteries. They check for polarity and if there isn't any sometimes they don't seem to do anything. There's probably nothing wrong with it. Reply to this message | Report message

New Sun 27 Feb 11 14:30   A very flat battery - -

Whilst on the subject. In compounds there's obviously a few flat batteries, and no one ever connects a jump pack for more than 20 seconds before trying to start the car, usually works too. There was a time when you jump started a car (Fords most memorable) that you could leave the flat batteried car ticking over (incl fast tickover by brick.;) all day and the battery wouldn't charge, however turn something on eg flashers (now standard practice so everyone knows it's runnng) and the alternator will charge fine. Obviously the alternator needs something to work on to tell it the batt's flat, but why isn't the normal electricals used with engine running enough? Reply to this message | Report message

New Sun 27 Feb 11 14:47   A very flat battery - AnotherJohnH

>> yet my jump leads alone would start a completely flat 12 litre lorry engine no bother , >> work that one out. Easy. 24 volt electrics on your lorry, 12 volt on vans and the like. Watts=(V squared)/r twice the voltage gives four times the power (Watts) for the same lead resistance (r). Reply to this message | Report message

New Sun 27 Feb 11 15:13   A very flat battery - Iffy

I've just had a look at the instructions for an Optimate charger. It says it is essential to disconnect a deeply discharged battery before charging. I wonder if all of the smart chargers - including mine - will charge a dead flat battery provided it's disconnected. Worth a try next time, which I hope there won't be. www.accumate.co.uk/OptiMate%203%20instructions.pdf Reply to this message | Report message

New Sun 27 Feb 11 15:33   A very flat battery - jc2

My best charger is a "Marble Arch Motor Supplies" one going back to the 50's-NO electronics at all. Reply to this message | Report message

New Sun 27 Feb 11 15:42   A very flat battery - Zero

>> My best charger is a "Marble Arch Motor Supplies" one going back to the 50's-NO >> electronics at all. Unless you count the rectifier. Reply to this message | Report message

New Sun 27 Feb 11 16:34   A very flat battery - Ted

I have both a Lidl and Aldi ' intelligent ' chargers. I knew, when I bought them, that they needed some power in the battery to kick them into life. They are specifically to keep the bike and the Jowett up to speed and they do the job fine. Jump leads are really the key to making a car spin over like it's got a pair ! £1.99 from the garage..no good. Cheap power packs, look impressive...mine went in the bin ! I have a set of 18 ft ones made out of MIG welding cable. They cost a bomb when I bought them about 30 yrs ago....and I bought 2 sets, for the truck and the van. I have a set I made myself out of Rover P5/6 battery cables. vicious clamps but don't half whap an engine over. Hard to coil so they hang in the garage. I did make a pair about 25 ft long to jump start cars on the hard shoulder and in awkward positions by going over the top.. My' proper ' battery chargers are a 40 yr old one, held together with tie-wraps but has a gauge and works fine. A plug in that has a 6 volt option for the Velocette and a small modern one which has been borrowed by persons unknown...or unremembered ! Grrrrr. A good bet is to get a normal charger as well as the Lidl type. Not very expensive and you can be confident that it's putting you some volts in. Ted Reply to this message | Report message

New Sun 27 Feb 11 16:49   A very flat battery - Zero

the secret of course is to take the keys out of the car. Reply to this message | Report message

New Sun 27 Feb 11 17:39   A very flat battery - hawkeye

>> the secret of course is to take the keys out of the car. >> then there would be no thread at all. Reply to this message | Report message

New Sun 3 Apr 11 22:31   A very flat battery - henry k

>>I have both a Lidl and Aldi ' intelligent ' chargers. I knew, when I bought them, that they needed some power in the battery to kick them into life." www.lidl.co.uk/cps/rde/xchg/lidl_uk/hs.xsl/19226.htm This video clip with its comprehensive demo says that it will charge a battery that has been full discharged for a long time with the reactivation mode. Reply to this message | Report message

New Sun 3 Apr 11 22:45   A very flat battery - henry k

I bought an Aldi version a while back but have yet to RTFM or use it. I have just looked at the info and it says that you can charge deep-discharged 12V batteries. It appears that it will need 3.8V to start working then some thinking time etc. Glad I have the details in the box. Reply to this message | Report message

New Sun 3 Apr 11 23:27   A very flat battery - Ted

I have both stores offerings. The Lidl one is hooked up to the bike all the time. The other is on the Jowett.. I needed to start the car yesterday to move it out of the garage. It started almost before I'd pressed the button ! Both good purchases imo. I'm going to fit remote charging points to the car, it's a bit of a fag removing the back seat and floor boards to get at the battery. I use my two other chargers for ' dead flats '. Ted Reply to this message | Report message