Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 8th December 2021, 20:45   #1
Mansfield
Regular poster
 
Rover 75 Saloon

Join Date: Feb 2012
Location: Wakefield
Posts: 82
Thanks: 1
Thanked 26 Times in 14 Posts
Default Battery draw/drain

So I came out to the car this morning to a flat battery, first time it's ever happened. Jump stated the car and ran fine, alternator over 14.3v and it charged up on the way to work, I removed the battery and did a battery test, battery very good with all cells fine, then fully charged with ctek charger and reconnected, then with an amp clamp did a battery draw test, found when locked 0.3a for a few mins then 0.1a when asleep. thought this was high so messed with the fbh remove relay I have fitted and found a bad connection, fix this and the draw dropped to between 0.07 and 0.08 amps. Is this classed as a high current draw or okay.

Personally I thought anything under 0.1 amp is acceptable

Thanks in advance for any replys

Sent from my SM-G981B using Tapatalk
Mansfield is offline   Reply With Quote
Old 8th December 2021, 20:53   #2
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

With your latest check all is OK now.

PS. After having a flat battery a 24 hour charge is really required.
COLVERT is offline   Reply With Quote
Old 8th December 2021, 20:55   #3
Mansfield
Regular poster
 
Rover 75 Saloon

Join Date: Feb 2012
Location: Wakefield
Posts: 82
Thanks: 1
Thanked 26 Times in 14 Posts
Default

Battery has been fully charged then auto dropped onto trickle for a few hours, will be fine and it's gonna get another charge at the weekend.

Sent from my SM-G981B using Tapatalk
Mansfield is offline   Reply With Quote
Old 8th December 2021, 21:16   #4
MSS
This is my second home
 
Rover 75CDT, Jaguar XF-S 3.0V6, V'xhall Omega V6 Estate, Twintop 1.8VVT, Astra Estate and Corsa 1.2

Join Date: Dec 2007
Location: Suffolk
Posts: 7,078
Thanks: 283
Thanked 624 Times in 440 Posts
Default

On a CDT I would investigate a long-term drain of anything over 50mA.

See https://www.the75andztclub.co.uk/for....php?p=2901167
MSS is offline   Reply With Quote
Old 8th December 2021, 21:27   #5
Mansfield
Regular poster
 
Rover 75 Saloon

Join Date: Feb 2012
Location: Wakefield
Posts: 82
Thanks: 1
Thanked 26 Times in 14 Posts
Default

Quote:
Originally Posted by MSS View Post
On a CDT I would investigate a long-term drain of anything over 50mA.

See https://www.the75andztclub.co.uk/for....php?p=2901167
I've had it on the drain and I've pulled all the fuses under the bonnet and none of them make a difference. would 0.08 max be a concern and cause an overnight flat battery

Sent from my SM-G981B using Tapatalk
Mansfield is offline   Reply With Quote
Old 8th December 2021, 21:33   #6
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

Quote:
Originally Posted by Mansfield View Post
I've had it on the drain and I've pulled all the fuses under the bonnet and none of them make a difference. would 0.08 max be a concern and cause an overnight flat battery

Sent from my SM-G981B using Tapatalk
Impossible for a fully charged battery over night.

If that happens it seems like your battery is on its last legs and is not taking a charge.--
COLVERT is offline   Reply With Quote
Old 8th December 2021, 21:52   #7
MSS
This is my second home
 
Rover 75CDT, Jaguar XF-S 3.0V6, V'xhall Omega V6 Estate, Twintop 1.8VVT, Astra Estate and Corsa 1.2

Join Date: Dec 2007
Location: Suffolk
Posts: 7,078
Thanks: 283
Thanked 624 Times in 440 Posts
Default

Quote:
Originally Posted by Mansfield View Post
I've had it on the drain and I've pulled all the fuses under the bonnet and none of them make a difference. would 0.08 max be a concern and cause an overnight flat battery

Sent from my SM-G981B using Tapatalk

Are you sure your clamp meter is capable of measuring DC current? Many are not.

For a battery in good condition, .08A would drain a fully charged 096 CDT battery in about 25 days.

Could it be that your interior lights remained on due to frozen door sensing contacts?

As COLVERT says, I would get the battery to a fully charged state by charging it for 24 hours and then repeat the tests.
MSS is offline   Reply With Quote
Old 10th December 2021, 21:42   #8
COLVERT
This is my second home
 
R75 Saloon.

Join Date: Feb 2009
Location: France/or Devon.
Posts: 14,003
Thanks: 3,851
Thanked 2,167 Times in 1,816 Posts
Default

With the sort of trouble you are having with your battery discharging so quickly you really need a garage to drop test it.

This will give the best idea about the condition of the plates and acid in your battery.
COLVERT is offline   Reply With Quote
Old 11th December 2021, 11:25   #9
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

Quote:
Originally Posted by Mansfield View Post
... I've pulled all the fuses under the bonnet and none of them make a difference.
Lewis, I'd be interested to know if your quiescent current reduces when you unplug the windscreen wiper motor (as mine does). You'll find the connector after lifting the OS plenum cover.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 21:50.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd