My battery goes flat after a week with nothing turned on what should the amps drain be in amps I have .06 amps does anybody know what it should be?
thanks Kay

Last edited by kay on 8th Nov 2010 11:05pm. Edited 1 time in total

i'm sure i've seen some posts re this somewhere on the forum....have you done a search? ... - .- -.




Y. O. L. O.
.

Yes I did a search but no result on what it should be
Kay

i would be interested in answer to this aswell, mine only draws between 40 and 50 milliamps fluctuating but it too drains the battery and only just starts after 5 days. my local says it should draw less than 30 milliamp but a quick search on the net and i came across a few people saying a sleeping bcm draws 40 milliamps, confused. i went through all the fuses one by one and none of them made any difference to the power drain in a positive way, i even disconnected the satnav and it still draws the same power.

hello. I can only speak from personal experience having had these issues as well. There may be other solutions but what worked for me was simple and inexpensive. Buy a good battery and have a "battery tender" (not a recharger, a tender) PROPERLY installed. When you know the car will be sitting for a few days, simply plug it in. Fully healthy battery = happy RR, IMHO. You may also find this helps with other "gremlins" as well. I have

mike.

kay wrote:

Yes I did a search but no result on what it should be
Kay

I don't know if there is an 'exact' figure for at-rest draw on the battery in the FFRR - it would vary dependent on equipment levels. I've never seen one.

A bit of math makes this problem easy, tho: at 50mA draw, the RR uses 1.2A over 24hrs (50mA/h x 24h). The battery in the RR is between 90 and 110aH depending on model and spec. After 5 days you've used 6A, after 25 days 30A. The motor should start with 60aH left easily - even on the coldest of days.

It used to be that simple cars with electric clocks and maybe an electronic radio with a memory used 10-20mA at rest. Add an alarm and under 30mA is fine - but is virtually no difference to 40 or 50mA. The RR is not simple, tho, and the P38 was somewhere around 60-80mA. I'd think that the LM has improved as far as electrics go and draws less, but I wouldn't worry under 80mA. And even then, the car should start fine after 5 days (your RR should be fine after 5 days even at 300mA draw - tho this would def not be normal).

The trouble is, you're only seeing a snapshot of what happens over 24hrs. This is where the difficulties lie. Finding a constant draw is easy but finding an item that draws every now and again is much more difficult.

I'd suggest starting with the simple causes and checking the battery before moving on to more complex searches. 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

The figures quoted for the battery are when it's new. A 3 year old 110aH battery is going to be more like half that in reality.

Try leaving the headlights on for an hour and see if it starts then. It should do if the battery is in good nick but I think you'll find it won't. Lights & Ignition etc should draw about 20 amps which would take 20aH out which would leave plenty to start the motor.

If you have to replace the battery, get the best you can find. Winter's a cummin' and that's hard on a battery.

Dom.

The drives door central locking doesn't seem to work at the moment like its stiff would this be the cause of the battery flattening

Kay

Unlikely. Even if it were to draw large currents due to being stiff, it would not operate for long enough to flatten the battery.

Do yourself a favour and get the battery tested. That way you'll know for sure if it's just a weak battery.

Fitted a new battery 110ah bosch the battary is still loosing charge just lasting longer, so there is a drain somwhere. Now its frosty at night the screen is frosty but the O/S is clear over where the dials & steering wheel is does this show where the fault is
Kay

If you're saying there is a part of the windscreen which looks like the heated screen elements have been on ------ they probably have been on (unless you have nice kind Pixies defrosting your screen) and they have mahoosive current draw. Much more than the heated rear window as there's a lot more element wires.

Easiest way to prove is to remove the fuse which protects the heated front screen and see if it still happens.

Dom.

if its the heated front screen thats on all the time then logically the whole screen would be defrosted..i suspect something around or in the speedo part of the dash is generating just enough heat to clear the part of the screen, i cant think what it could be . ... - .- -.




Y. O. L. O.
.

scarey wrote:

if its the heated front screen thats on all the time then logically the whole screen would be defrosted.

Logic has nothing to do with it!

IIRC, the screen has a left and right circuit (perhaps a middle one too). When the screen on my D3 failed it was clearing one side but not the other. The older I get, the more I realise that people confuse wrinkles for wisdom

kay wrote:

My battery goes flat after a week with nothing turned on what should the amps drain be in amps I have .06 amps does anybody know what it should be?
thanks Kay

That would be 6/100ths of an amp - or 60/1000ths which = 60mA. This alone will not be causing the problem on a new 110aH battery.

I wouldn't think its your windshield heater - your battery would be dead after a night (is the section of defrosted windshield really clear top to bottom with sharply defined lines to the R and L? The screen has a L&R circuit - in theory it could be a stuck relay on one side. But even 1/2 of the windshield heater draws too much current for a week.)

As I said, when you connect an ammeter to the vehicle you are only seeing a snapshot of what happens. In the worst case, you'll need a logging ammeter connected to the car for a longer period.

RF interference is a possibility - even on the MKIII (it's common on the P38). Does this happen everywhere you leave the car parked (or do you always leave it in the same spot)? 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)