battery drain

keithemm · Post by **keithemm** » Thu Jan 08, 2004 8:49 pm

hey there,

although i have many problems with my 480, the electrical faults have to be the most annoying, in particular, the battery. If i don't use the car every day, the battery usually drains in 30 hours ish. I've checked the battey by disconnecting it, and it holds it's charge. I know the alternator is ok as that has been checked. I checked the current being drawn using a multimeter, and it was 0.55A, is this quite alot? Does anyone have any ideas as to what i should do?

thanks

volvofox · Post by **volvofox** » Thu Jan 08, 2004 8:59 pm

this is very much ! it has to be around 0,003 Amp this after all timer relays have been down, and of course the hood (switch) closed (taking out the lamp is not enough, its a double switch in there, there is still current flow if you don't apply the sitch knob (its in the female part of the lock)

so connect the meter between the + lead and the plus clamb(loosen it) , close the hood fully, wait, and see what happens. than take out the fuses one by one, and notice the drop every time. Also remove any audio or extra electronics you have mount.

This is the way to have a small clue were to search.

I had this a while ago, it were bad doorlockswitches (alarm, and int. lights), that drained my battery.

this is a nice job.

sakis480 · Post by **sakis480** » Fri Jan 09, 2004 7:04 am

Hi there!!

Volvofox is right u need to do a small search with the polymeter to find where the "leak" is..be reminded that the battery drain is common problem for the 480 specially in winter...use vazeline on the battery poles, also another idea would be to replace the batt with a larger capacity one in amps/hour...thats what i did and its fine...if u swap the bat u need to install a larger base for it.....

luck sakis

keithemm · Post by **keithemm** » Fri Jan 09, 2004 11:01 am

I considered doing a similar thing with the fuses. Not sure if i'll be able to shut the bonnet with the wires connected to the battery and lead though.. I'm determined to find out what is draining it, onec i find out which fuse caused the biggest drop, I'll let you know.
Thanks!

dragon · Post by **dragon** » Fri Jan 09, 2004 1:40 pm

I think it's always worth investing in a set of extra long test leads for a multimeter, that way you can have the leads drop out under the car and not need to worry about trapping wires in the bonnet... definately 5 quid well spent

volvofox · Post by **volvofox** » Fri Jan 09, 2004 6:31 pm

keithemm wrote:I considered doing a similar thing with the fuses. Not sure if i'll be able to shut the bonnet with the wires connected to the battery and lead though.. I'm determined to find out what is draining it, onec i find out which fuse caused the biggest drop, I'll let you know.
Thanks!

you must !

if the hood is opened, there are two circuits running: one keeping the hood lamp on, one running through the cem for the door open warning light , and the standard car alarm !!!!!

Measuring like this even a healthy 480 can give too much drain ! You 'll never reach the 300 miliampere line !

keithemm · Post by **keithemm** » Fri Jan 09, 2004 7:43 pm

volvofox wrote:
keithemm wrote:I considered doing a similar thing with the fuses. Not sure if i'll be able to shut the bonnet with the wires connected to the battery and lead though.. I'm determined to find out what is draining it, onec i find out which fuse caused the biggest drop, I'll let you know.
Thanks!
you must !

if the hood is opened, there are two circuits running: one keeping the hood lamp on, one running through the cem for the door open warning light , and the standard car alarm !!!!!

Measuring like this even a healthy 480 can give too much drain ! You 'll never reach the 300 miliampere line !

I don't seem to have a hood lamp, at least, if there is one, it doesn't come on, although you are right about the warning light. i'll have to get some longer test leads from somewhere, not sure where though yet.

keithemm · Post by **keithemm** » Tue Jan 20, 2004 4:44 pm

hello all,

just tried removing each fuse to see if there would be a drop. I found when i first connect the multimeter between the red (+) battery terminal, and the red (+) clamp, i get a reading of 0.50A, but after 5-10 seconds, that drops to 0.37/0.38A. When i remove fuse 1 (which according to my owners manual is for courtesy lights, boot light, engine compartment light, glove compartment and ignition switch lighting, cigar lighter, clock and radio.) It's a 15 amp fuse, when i take it out, the current drops by 0.01A, and when i replace it, it jumps up to 0.50A, then again, after a few seconds, drops to 0.37/0.38A. The other fuse which caused a drop was number 4 (headlamp retracting motors, central locking system, aerial) 30 amp fuse. This caused a drop of 0.02A, slightly bigger, and no big jump when i replaced it. This is slightly odd as my central locking doesn't work. Please note that all my interior lights are switched off via the courtesy light switches, i also checked the boot light and glove compartment light to ensure they were off. Any ideas anyone? Where do I go from here?

many thanks

volvofox · Post by **volvofox** » Tue Jan 20, 2004 11:35 pm

youre headding towards the same problem i had.

this drop however is normal: there are several relays that only switch off after their adjusted times. ( like the lights, alarm system etc.

now there is the problem : them courtessy lights and the alarm. the doorlock switches don't work (or bad connectors) and thus the cem keeps a circuit going, draining your battery.

so remove drivers door (and look at other doorlockswitches incl. hood and hatch if no luck) measure the switches with multimeter, look at how they are fixed for working, and clean /check all connectors, also the big one in the car behind the panel in front of the a- base column.

maybe use the search machine on this data bank called 480 club europe: you will be surprized....

Ettore Bugatti · Post by **Ettore Bugatti** » Fri Jan 23, 2004 11:39 am

last week I grapped a multimeter open the bonnet and started measuring.
First I removed a batterystrap then put the multimeter between the battery and the strap.
Then I measured with all the fuses in place a current of 165 mA (1 mA=0,001 A).
Then I put my finger in the bonnet lock and the current decrease to 61 mA.
After this I removed fuse nr 1, measured the current, put my finger in the bonnetlock and measured again.
Then I put fuse nr 1 back and removed fuse nr 2 and measured twice(bonnetlock)
All the other fuses has been treaten like this.

Now for the results
Fuses current(bonnet open) current(bonnet closed)
all 165 mA 61 mA
all-nr1 161 mA 60 mA
" -nr2 121 11
" -nr3 164 57
" -nr4 164 60
" -nr5 163 60
" -nr6 163 59
" -nr7 164 60
" -nr8 163 59
" -nr9 163 59
" -nr10 163 60
" -nr11 163 58
" -nr12 163 59
" -nr13 162 59
" -nr14 163 59
" -nr15 162 59
" -nr16 161 58
" -nr17 161 57
" -nr18 158 56
" -nr19 158 55
" -nr20 158 56
" -nr21 159 56
" -nr22 158 56
" -nr23 161 56
" -nr24 161 57
" -nr25 161 57

When I calculated the current by fuse and add these together I got 127 mA for bonnet open and 122 mA for bonnet closed (Which is offcourse the same). And this is a little strange because it means that when the bonnet is open I lose a current of about 40 mA which is included in the fuses but when I closed the bonnet something adds 60 mA.
BTW is the drop (44mA/0,044A) off fuse nr 2 OK?
anyone an explaination?
Sorry for the long story

Volvo 480 Club Europe

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Measuring currents