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[Mr Skrunts]

If a battery is completely flat there are 2 major considerations :

1. How long has it been flat ? If a lead-acid is left in an uncharged state for more than a few days the lead start to sulphate, this wrecks a battery PDQ. A "smart" charger that gives higher voltage pulses over a very short time can sometimes fix this, but it is often time to replace the battery

2. A car electrical system has no current control, only voltage control, usualy at around 14 v. The battery "state of charge" forms the resistance that limits the amperage that flows into a battery, the higher the charge, the higher the resistance, so the current flow is reduced. A very discharged battery has a very low internal resistance. This can lead to extremely high current flow through the charging circuit, hopefully fuses will protect the alternator from damage, but there is a risk. The high current flow through the battery can lead to overheating (boiling) of the acid, and/or distortion of the plates. If they touch an internal short forms and the cell dies. This is not recoverable.

For the above reasons it is preferable that a discharged battery is charged "off car" by a dedicated charger. These have internal controls that limit the maximum current to prevent (2), and  "smart" chargers have a chance of fixing (1)

A 60 amp hour battery fully discharged will take about 20 hours at 3 amp rate to recharge. If you let the car charge it up in 2 hours .. you've stuck an average of 30 amps at it !!! The maths is quite simple. But what was the "starting" current flow ... probably much higher  ??

HTH

So even though the battery is not yet 6 months old it could be stuffed then.

How does that affect my warranty.

Also how do I know it was a 100% the day I bought it.

[hotel21]

If a battery is completely flat there are 2 major considerations :

1. How long has it been flat ? If a lead-acid is left in an uncharged state for more than a few days the lead start to sulphate, this wrecks a battery PDQ. A "smart" charger that gives higher voltage pulses over a very short time can sometimes fix this, but it is often time to replace the battery

2. A car electrical system has no current control, only voltage control, usualy at around 14 v. The battery "state of charge" forms the resistance that limits the amperage that flows into a battery, the higher the charge, the higher the resistance, so the current flow is reduced. A very discharged battery has a very low internal resistance. This can lead to extremely high current flow through the charging circuit, hopefully fuses will protect the alternator from damage, but there is a risk. The high current flow through the battery can lead to overheating (boiling) of the acid, and/or distortion of the plates. If they touch an internal short forms and the cell dies. This is not recoverable.

For the above reasons it is preferable that a discharged battery is charged "off car" by a dedicated charger. These have internal controls that limit the maximum current to prevent (2), and  "smart" chargers have a chance of fixing (1)

A 60 amp hour battery fully discharged will take about 20 hours at 3 amp rate to recharge. If you let the car charge it up in 2 hours .. you've stuck an average of 30 amps at it !!! The maths is quite simple. But what was the "starting" current flow ... probably much higher  ??

HTH

So even though the battery is not yet 6 months old it could be stuffed then.

How does that affect my warranty.

Also how do I know it was a 100% the day I bought it.

All good and relevant points...

The retailer will maintain it was 100% the day you took it away.

You thereafter used it as per the manufacturers recomendations (who's to check?)

Its now rubber ducked....

Take battery and receipt back to supplier and request/demand a replacement as its a duffer...

sorted....  

[Mr Skrunts]

If a battery is completely flat there are 2 major considerations :

1. How long has it been flat ? If a lead-acid is left in an uncharged state for more than a few days the lead start to sulphate, this wrecks a battery PDQ. A "smart" charger that gives higher voltage pulses over a very short time can sometimes fix this, but it is often time to replace the battery

2. A car electrical system has no current control, only voltage control, usualy at around 14 v. The battery "state of charge" forms the resistance that limits the amperage that flows into a battery, the higher the charge, the higher the resistance, so the current flow is reduced. A very discharged battery has a very low internal resistance. This can lead to extremely high current flow through the charging circuit, hopefully fuses will protect the alternator from damage, but there is a risk. The high current flow through the battery can lead to overheating (boiling) of the acid, and/or distortion of the plates. If they touch an internal short forms and the cell dies. This is not recoverable.

For the above reasons it is preferable that a discharged battery is charged "off car" by a dedicated charger. These have internal controls that limit the maximum current to prevent (2), and  "smart" chargers have a chance of fixing (1)

A 60 amp hour battery fully discharged will take about 20 hours at 3 amp rate to recharge. If you let the car charge it up in 2 hours .. you've stuck an average of 30 amps at it !!! The maths is quite simple. But what was the "starting" current flow ... probably much higher  ??

HTH

So even though the battery is not yet 6 months old it could be stuffed then.

How does that affect my warranty.

Also how do I know it was a 100% the day I bought it.

All good and relevant points...

The retailer will maintain it was 100% the day you took it away.

You thereafter used it as per the manufacturers recomendations (who's to check?)

Its now rubber ducked....

Take battery and receipt back to supplier and request/demand a replacement as its a duffer...

sorted....  

Dont you worry about that, I know how to be polite infront of an audiance full of customers .

Thing is it's Pentagon in Sheffield and I heard the group were having problems.  So hope they are still open.

[ngrainqey]

you should be ok to take it to another pentagon dealer/garage and they should sort it, aslong as you have the reciept

[willyboy]

How do you check that its total donald ducked mine is only few months old was flat as it can be after like 2mths of non use,but did open cent locking, so ye who knows abaht batteries whats the time limit now from being fully charged to see if it holds the charge with just alarm set but not using car at all ? 2 /3  mths ? or should it be more ?
I'm sure they will test it before replacing it & it maybe some what damaged but it will still probably show ok !
I have one of these chargers supposed to be pretty good
http://www.vertar.com/ctek/ctek-multi-xs-3600/
supposed to help recover slightly sulphated batteries

[Kevin Wood]

How do you check that its total donald ducked mine is only few months old was flat as it can be after like 2mths of non use,but did open cent locking, so ye who knows abaht batteries whats the time limit now from being fully charged to see if it holds the charge with just alarm set but not using car at all ? 2 /3  mths ? or should it be more ?

Nope. I would say that after a month or so, the battery would be pretty flat. The alarm, etc. will drain it slowly, but it will also naturally lose its' charge over time. Whether permanent damage is done depends on how long it has been left flat.

That charger looks good for permanent trickle charging for cars that are parked up for long periods.

Kevin

[Mr Skrunts]

Can the Alarm be disabledwithout causing running problems for the car?

[Ian_D]

Once its jump started, really needs a fair few miles to get it fully back, and thats without any electrical load such as headlights, heater fans, stero and the like.  No doubt someone will quote electrical sums somewhere along the line, but I would prefer to put it on an overnight trickle charge, if possible....

Sadly not.

I was allways of the understanding that the car electrical system would run the car on its own with out the battery connected (this may well have been on older cars , and of course once the car was running.) and in theory does if the battery is flat any way.

Therefore isnt the charging system capable of running the whole car and charging the battery at the same time even with the headlights on.

Just a thought as I know someone will know the proper logic to it all.

TIA.  

Yes indeed Skruntie, a battery is in the system to purely restart the engine when stopped, and the alternator is quite efficient enough to keep the engine going with even 'accessory' loads on, but of course the less load there is the greater the amount of power placed in storage within the battery! 8-) 8-) 8-).

I think you'll likely opps things up taking the battery off a modern running engine. My understanding is that the alternator needs to be loaded up, and as ECU's require a steady 12 volts rather than the 13.5/14 volts that the alternator kick out. The last car I took the battery off while it was running, was a Cortina.

Yes agree.. I bet you could unplug the battery off an omega, and it would keep running, but I doubt the electrics would last very long, esp if you switch heavy loads on and off while reving engine etc! The voltage spikes would be fairly high at a guess!

When I worked at a car garage we had a scrap alfa (was a 2.0 Tspark with a million miles on it), I remember starting that using jump leads. Anyway, once we got it running, I went to remove the jump leads, and pulled the terminal block off the battery! Car was running for a few seconds like that with no battery attached! Chucked leads on the floor, and then just reconnected the battery (while it was running still). Nothing intresting happened though (apart from a small spark as the connection was made), it just kept ticking over!    

[Mr Skrunts]

Well, My mate brought up his boost pack, got into the car via the key, then it took ages to get the bonnet up, latch needs adjusting. (put some WD40 on it for now)

Booster pack on, about 5 turns of starter and it fired up no probs.  So will try it tommorrow and go for annother run.  Engine was running/driven a total of 2 hours+

Not driven it for 3 months till today, got a faulty brake bulb connector through being parked up.  Only been started twice in 3 months and one of those my mate took the car on a dumpit site run for me so no complaints really.

Fuel gauge light has just come on tonight with 507 miles on trip.  Cant remember adding fuel since I last brimmed the tank,  Rarely go above 50 when I use it, (not like the other car,  )  Dont know what my ave mpg will be, but wishfull thinking if it has done 500 since brimmed.  Not been driven heavy so will never know.

Brakes had rusted over but working fine.  Tyres were down to 24,25,25,and 28.  So all been set on a auto cutout pump at 34 psi as per Marks DTM finding on MPG ecconomy.  Getting 36+ on 40 mph dual carriageway so will start doing spme monitoring.  Generally gets better as speeds rise.  (On the flat of course)



Nice to be back on the road as a New Year start though.

[Kevin Wood]

First thing to do is brim the fuel tank with decent fuel. Dilute any stale fuel in the tank.

Kevin

[blue_dream]

Hi
   just been reading your thread, am i right in saying that you need to drive the car for aleast 30 miles at a steady drive for both ecu's to relearn from totally flat battery.
  The battery must be good condition, to achive good output of engine and other parts.
  Have you thought of using a solar pack which plugs into the cig lighter, same as used to change battery to stop memory lost

[Entwood]

Hi
   just been reading your thread, am i right in saying that you need to drive the car for aleast 30 miles at a steady drive for both ecu's to relearn from totally flat battery.
  The battery must be good condition, to achive good output of engine and other parts.
  Have you thought of using a solar pack which plugs into the cig lighter, same as used to change battery to stop memory lost

Certainly on my Miggy a relay disconnects the ciggy lighter about 8 minutes afetr the key is removed and the doors shut ... so the solar plug-ins won't do a great deal unless connected directly to the battery

[Andy B]

Hi
   just been reading your thread, am i right in saying that you need to drive the car for aleast 30 miles at a steady drive for both ecu's to relearn from totally flat battery.
  The battery must be good condition, to achive good output of engine and other parts.
  Have you thought of using a solar pack which plugs into the cig lighter, same as used to change battery to stop memory lost

Certainly on my Miggy a relay disconnects the ciggy lighter about 8 minutes afetr the key is removed and the doors shut ... so the solar plug-ins won't do a great deal unless connected directly to the battery

I'm pretty sure both of mine are ignition fed and die as soon as the ignition is turned off --- mini face lift.

[Mr Skrunts]

If some could point me in the direction of a solar panel that will cover the active items when a car is locked I would appreciate it.  I wouldput a supply in just for that purpose.

TIA.  

[Auto Addict]

I bought one of these http://www.machinemart.co.uk/shop/product/details/atc12v-car-battery-charger/path/

I cut off the clamps, and used one of these http://www.machinemart.co.uk/shop/range/guid/3434A6A5-43E8-4A2C-84A8-9E7739EDE65A

One end connected to the battery with heavy duty wire (you need 30 strand +) fitted an inline fuse (1 amp), plug secured under front bumper.

I can trickle charge the battery at any time, without lifting the bonnet.

As per MDTM, you will not damage the alternator with such a low charge.