mk1 battery drain

[James Good]

i got a new battery about 3 weeks ago and as in lockdown havent driven it much but when i went to strart it a few days ago it just clicked and didnt start 

i left it for a day then tryed again but this time i had to use the key to unlock the door as the central locking didnt open it and even the clock was dead

ive ordered a battery charger once it has bee charged i need to find out what is draining the battery 

how would i go about and do this?

thanks 

 

 

 

 

last mouth the car wouldn't start one day and the fuse for the fuel pump had blown- replaced fuse 

aftermarket radio fitted 1 year ago-all working fine until about a 2 months ago the reverse cam stopped working

[Luke4efc]

Get a multimeter, remove the negative terminal and put one lead on the battery terminal and the other lead on the negative cable. Set your multimeter to amps and check how much current you have. My guess is you'll have a draw above 200mA if your battery keeps going flat.

Start removing fuses 1 by 1 till the current drops off, then you've identified the circuit at fault.

When you do the test, make sure the doors are locked, all lights etc. are switched off and you've left the car for half an hour ish. You'll get a false reading if you don't, as some of the modules will be awake and drawing current.

[James Good]

well ive taken out the battery this morning it was reading 3.82 before i put it on charge now just got to wait for it to charge................

[williamweb]

39 minutes ago, James Good said:

well ive taken out the battery this morning it was reading 3.82 before i put it on charge now just got to wait for it to charge................

No need to lump a heavy car battery around.Charge in the car if convenient and off road👍

[James Good]

just a quick question...regarding battery while waiting for it to fully charge so i can do a parasitic draw test i cheked the batt and it said 12.40 then it went down to 12.38-12.36 quickly so i take it the battery is faulty as its not holding charge ?

the battery is only 2 mths old 

should i wait till fully charged to to test of just get new batt?

thanks

On 3/8/2021 at 11:34 AM, williamweb said:

No need to lump a heavy car battery around.Charge in the car if convenient and off road

dont have off street parking

[williamweb]

5 hours ago, James Good said:

just a quick question...regarding battery while waiting for it to fully charge so i can do a parasitic draw test i cheked the batt and it said 12.40 then it went down to 12.38-12.36 quickly so i take it the battery is faulty as its not holding charge ?

the battery is only 2 mths old 

should i wait till fully charged to to test of just get new batt?

thanks

dont have off street parking

How long has the battery been on charge.12.4 is less than 50% charged👍

[James Good]

i put it on yesterday 12noon turned off at 11pm as didnt want to leave on over night and i put it back on at 10am today its a 6amp charger

 

[James Good]

well last night it was 12.83 and i checked it just now and its 12.58

and it not in the car yet i will check the level for a few hrs to see if it drops

is this normal?

 

[williamweb]

1 hour ago, James Good said:

well last night it was 12.83 and i checked it just now and its 12.58

and it not in the car yet i will check the level for a few hrs to see if it drops

is this normal?

 

Definitely not holding it’s charge.I would expect a better performance from a new battery.A good idea to invest in a smart charger👍

[James Good]

should i get a new battery? 

[williamweb]

30 minutes ago, James Good said:

should i get a new battery? 

Take it back with your receipt and ask from another one👍

[James Good]

well so far its holding was 12.58 at 11am at 1 pm was 12.58 i will check though out today as weather is crap out 

 

[James Good]

battery 11am-12.58v

              1pm-12.58v

               3pm-12.57v

                5pm-12.56v

                 7pm-12.55v

 

think i need to get a replacement battery even tho its 2-3 mths old

[Luke4efc]

Most decent batteries come with a warranty of at least 4 years.

[Waggy]

Why did you have to change the battery 3 weeks ago? Are you now having the same problem? When you measured 12.83 volts had you just taken it off charge or was it still charging or had you let it settle for an hour? 12.55 volts is a perfectly acceptable state of charge, see how it goes for now. No use wasting more money on batteries if you haven't cured the reason they are being drained.

[James Good]

the previous battery was 5 years old 

12.83 yes that was when i took off charge 

what i will do tomorrow depends on weather is i will attach battery back to car and check for a  parasitic draw 

as i didnt drive the car with new batt for 2 weeks and when i did it was compleatley dead 

 

[Waggy]

battery 5 years old should not be a reason for buying a new one. Ignore the 12.83 if you had just been charging it, the important thing now if you can carry on testing is whether it holds the 12.55 ish. If it's still holding up in the morning then proceed to finding out if anything's drawing an abnormal current. Obvs you can take the battery back for testing, but probably will test ok or be replaced and you're no further forward, or take the car to a garage for checking, but that will cost you. Good luck, let us know how you get on.

[James Good]

this morning its 12.50 😞

 

[Waggy]

I've been for a good run this morning, stop start working ok, just measured battery volts - 12.31, so yours is nothing to be ashamed of! My thinking would be that you have a fault on the car draining the battery which has already seen off your original battery and severely damaged your new one, getting down to less than 4 volts will have taken its toll. Hopefully your battery will hold enough charge to let you put it back in the car until you can find the fault. You might have to keep charging it as you go. Once you've found the fault and corrected it, take it back and try and get it replaced (but I didn't say that) or at least get a replacement which should then last. Of course, you might just have been unlucky, the first battery giving up the ghost due to old age, and then getting a duff replacement. Either way, try and use the battery you have now to determine whether you have a fault drawing a high current or whether you have just been unlucky.

[James Good]

yes i will my mutimeter wire broke today got new cables coming tomoz so soon as they come then i will test the battery in the car and see whats going on 

[James Good]

this morning i put battery in and done draw test it came in at 0.40 and moving upto 0.47 then down to 0.40 that was just with bonnet open only 

after connecting the battery and running the car for 5 mins i checked  it was running 13.56 

 

[Luke4efc]

Have you started pulling fuses 1 by 1 till the current drops off? That's the next step if not.

It looks like your battery and alternator are fine.

[James Good]

3 minutes ago, Luke4efc said:

Have you started pulling fuses 1 by 1 till the current drops off? That's the next step if not

nope not yet how would i do that with just me? 

i take it 0.40-0.47 not good then?

[Luke4efc]

No that's way too high, an old mk1 should be virtually 0.

Place the multimeter on the windscreen so you can see it inside the car. Then remove a fuse, see if the number drops, if not put it back and remove another one. Keep doing this till the current drops off.

[Waggy]

52 minutes ago, James Good said:

nope not yet how would i do that with just me? 

i take it 0.40-0.47 not good then?

What type of meter are you using? Presumably it's capable of reading dc current and down to a few milliamps? Did you lock up and wait 20 minutes to take the reading so everything's had chance to go to sleep? It wants to get down below 30 mA I would have thought to be "normal".