Auto-elec question - standlby / leakage current from batteri

[Dennis]

I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

 

[Baron]

Dennis Inscribed thus:

I've a problem with a truck failing to start after 5 days sitting idle
- completely flat batteries, no ignition lights, no
"click-click-click", nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate, 800 CCA big lead acid units, each larger than a large 4WD
battery. The charging system works fine with over 28V at fast idle,
and around 26 at idle. It starts fine after a couple of days sitting
idle.


I've measured the standby current draw from the batteries with
everything switched off at around 150mA. As far as I can tell the
standby current mainly goes into the remote entry system and a 24/12V
converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Could be silt buildup in the bottom causing discharge internally. I've
seen similar batteries have had a couple of inches of thin sludge
material sat in the bottom.

If that is the case and they are of the type that can be disassembled,
then they can be drained, the plates lifted out and flushed with water
before reassembly with new acid and recharged.

HTH

--
Best Regards:
Baron.

 

[Dennis]

"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:ih7g31$9ln$1@news.eternal-september.org...

Dennis Inscribed thus:

I've a problem with a truck failing to start after 5 days sitting idle
- completely flat batteries, no ignition lights, no
"click-click-click", nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate, 800 CCA big lead acid units, each larger than a large 4WD
battery. The charging system works fine with over 28V at fast idle,
and around 26 at idle. It starts fine after a couple of days sitting
idle.


I've measured the standby current draw from the batteries with
everything switched off at around 150mA. As far as I can tell the
standby current mainly goes into the remote entry system and a 24/12V
converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Could be silt buildup in the bottom causing discharge internally. I've
seen similar batteries have had a couple of inches of thin sludge
material sat in the bottom.

If that is the case and they are of the type that can be disassembled,
then they can be drained, the plates lifted out and flushed with water
before reassembly with new acid and recharged.

HTH

--
Best Regards:
Baron.

Thanks for the suggestion Baron - pretty unlikely in my case as the
batteries (& the vehicle) are only a few months old.

I also make a point of keeping the tops of the batteries clean to prevent
possible discharge through the crap that collects there (especially in damp
conditions).

 

[Rheilly Phoull]

On 1/19/2011 8:04 PM, Dennis wrote:

I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

I guess mebbe you should disconnect the batts and see if the problem
does exist in the batteries themselves. If it does then it should be a
warranty situation ??

Cheers ...... Rheilly

 

[kreed]

On Jan 19, 10:04 pm, "Dennis" <no...@nowhere.com> wrote:

I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.

The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.

I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.

Comments or suggestions???

Thanks.

150ma @ 24v sounds a bit high to me for standby on such a system.

You might have to start pulling fuses and finding out exactly where
all this current is going to.
Put an amp meter across the supply, and pull the fuses one at at
time. IF there is any drop after
pulling a fuse, then you have to follow down the line and see what is
on that fuse.
It is possible that this load comes from more than one source.


I would also look at anything added to the system (after market
accessories, or recent work done).
There was a recent story in Silicon Chip about a car that had had
driving lights added, controlled by a
automotive relay. This relay failed and was replaced. This caused a
problem similar to yours

The problem turned out that the new relay had a slightly different pin
out to the old one, and this resulted
in the dashboard switch directly switching the lights, and the relay
coil held on constantly - slowly flattening
the battery.

 

[Dennis]

"Rheilly Phoull" <rheilly@bigslong.com> wrote in message
news:OOCdncwTjO6TAqrQnZ2dnUVZ_jydnZ2d@westnet.com.au...

On 1/19/2011 8:04 PM, Dennis wrote:
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should
have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.



I guess mebbe you should disconnect the batts and see if the problem does
exist in the batteries themselves. If it does then it should be a
warranty situation ??

Cheers ...... Rheilly

Good point - I was working on the assumption the batteries were ok.
thanks.

 

[John G]

kreed expressed precisely :

On Jan 19, 10:04 pm, "Dennis" <no...@nowhere.com> wrote:
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.

The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.

I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.

Comments or suggestions???

Thanks.


150ma @ 24v sounds a bit high to me for standby on such a system.

You might have to start pulling fuses and finding out exactly where
all this current is going to.

Put an amp meter across the supply, and pull the fuses one at at

time. IF there is any drop after
pulling a fuse, then you have to follow down the line and see what is
on that fuse.
It is possible that this load comes from more than one source.

Whatever you do DO NOT put an amp meter across the supply.!!!!

In series with the supply is OK but ACROSS will destroy the meter and
depending on it size maybe splash you with sparks.

It would be good if advice here was acurate.

--
John G

 

[Rheilly Phoull]

Another thing I forgot was dont rely on the alternator to charge the
batteries after they are flat (unless you are doing 12hour runs for a
couple of days) To recharge 2 large batteries needs putting them on a
decent charger until the electrolyte shows fully charged.
If you were just doing an hour or two that would not charge them and
give the symptoms you describe.

Cheers ...... Rheilly P

 

[Dennis]

"Rheilly Phoull" <rheilly@bigslong.com> wrote in message
news:1L-dnUpNo_LjTarQnZ2dnUVZ_jOdnZ2d@westnet.com.au...

Another thing I forgot was dont rely on the alternator to charge the
batteries after they are flat (unless you are doing 12hour runs for a
couple of days) To recharge 2 large batteries needs putting them on a
decent charger until the electrolyte shows fully charged.
If you were just doing an hour or two that would not charge them and
give the symptoms you describe.

Cheers ...... Rheilly P

I'll do that, I took it for a 40 minute run, but as you say that probably
hasn't fully charged the batteries up. Cheers.

 

[Dennis]

"John G" <greentest@ozemail.com.au> wrote in message
news76dnYhHrb_yVarQnZ2dnUVZ_gSdnZ2d@westnet.com.au...

kreed expressed precisely :
On Jan 19, 10:04 pm, "Dennis" <no...@nowhere.com> wrote:
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.

The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.

I've measured the standby current draw from the batteries with
everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should
have bugger all effect on such large batteries.

Comments or suggestions???

Thanks.


150ma @ 24v sounds a bit high to me for standby on such a system.

You might have to start pulling fuses and finding out exactly where
all this current is going to.

Put an amp meter across the supply, and pull the fuses one at at


time. IF there is any drop after
pulling a fuse, then you have to follow down the line and see what is
on that fuse.
It is possible that this load comes from more than one source.

Whatever you do DO NOT put an amp meter across the supply.!!!!

In series with the supply is OK but ACROSS will destroy the meter and
depending on it size maybe splash you with sparks.

It would be good if advice here was acurate.

--
John G

I have enough trouble keeping a fuse in my DMM as it is!

I'm sure kreed's comment just came out wrong.

 

[kreed]

On Jan 20, 3:30 pm, John G <greent...@ozemail.com.au> wrote:

kreed expressed precisely :



On Jan 19, 10:04 pm, "Dennis" <no...@nowhere.com> wrote:
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.

The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.

I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.

Comments or suggestions???

Thanks.

150ma @ 24v  sounds a bit high to me for standby on such a system.

You might have to start pulling fuses and finding out exactly where
all this current is going to.
Put an amp meter across the supply, and pull the fuses one at at
time.  IF there is any drop after
pulling a fuse, then you have to follow down the line and see what is
on that fuse.
It is possible that this load comes from more than one source.

Whatever you do DO NOT put an amp meter across the supply.!!!!

In series with the supply is OK but ACROSS will destroy the meter and
depending on it size maybe splash you with sparks.

It would be good if advice here was acurate.

--
John G

That is indeed correct. Thank you for picking that up.


acurate ?

 

[Metro]

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...

I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Just a thought . Any clocks or timers hooked up/? Is there a back-up alarm

battery for you security flat and attempting to charge continuously. Any GPS
type that regularly transmits reports. You never know. Silly things cause
silly faults.

 

[Dennis]

"Metro" <Home@home> wrote in message
news:4d392084$0$15070$afc38c87@news.optusnet.com.au...

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate, 800 CCA big lead acid units, each larger than a large 4WD battery.
The charging system works fine with over 28V at fast idle, and around 26
at idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Just a thought . Any clocks or timers hooked up/? Is there a back-up alarm
battery for you security flat and attempting to charge continuously. Any
GPS type that regularly transmits reports. You never know. Silly things
cause silly faults.

No GPS or alarms. Vehicle has 3 ECU's, a couple of 24/12V converters and a
remote access door controller. Leakage current drops back in steps to around
150mA then seems to be stable. I've decided to take it back to the
manufacturer Monday and let them sort it out.....

thanks

 

[kreed]

On Jan 21, 3:58 pm, "Metro" <Home@home> wrote:

"Dennis" <no...@nowhere.com> wrote in message

news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...

I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.

The electrical sytem is supplied by 2 x 12V batteries. These are 21 plate,
800 CCA big lead acid units, each larger than a large 4WD battery. The
charging system works fine with over 28V at fast idle, and around 26 at
idle. It starts fine after a couple of days sitting idle.

I've measured the standby current draw from the batteries with everything
switched off at around 150mA. As far as I can tell the standby current
mainly goes into the remote entry system and a 24/12V converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which should
have bugger all effect on such large batteries.

Comments or suggestions???

Thanks.

Just a thought . Any clocks or timers hooked up/? Is there a back-up alarm
battery for you security flat and attempting to charge continuously. Any GPS
type that regularly transmits  reports. You never know. Silly things cause
silly faults.

Yes, it could be something that pulls a significant load, but
intermittently.

 

[Metro]

"Dennis" <noone@nowhere.com> wrote in message
news:SL2dnT1wIuUttaTQnZ2dnUVZ_oednZ2d@westnet.com.au...

"Metro" <Home@home> wrote in message
news:4d392084$0$15070$afc38c87@news.optusnet.com.au...

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...
I've a problem with a truck failing to start after 5 days sitting idle -
completely flat batteries, no ignition lights, no "click-click-click",
nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate, 800 CCA big lead acid units, each larger than a large 4WD
battery. The charging system works fine with over 28V at fast idle, and
around 26 at idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with
everything switched off at around 150mA. As far as I can tell the
standby current mainly goes into the remote entry system and a 24/12V
converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Just a thought . Any clocks or timers hooked up/? Is there a back-up
alarm battery for you security flat and attempting to charge
continuously. Any GPS type that regularly transmits reports. You never
know. Silly things cause silly faults.


No GPS or alarms. Vehicle has 3 ECU's, a couple of 24/12V converters and a
remote access door controller. Leakage current drops back in steps to
around 150mA then seems to be stable. I've decided to take it back to the
manufacturer Monday and let them sort it out.....

thanks

I'll bet it's something silly albeit annoying. Let us know the outcome. It's

intriguing................

 

[Dennis]

"Metro" <Home@home> wrote in message
news:4d3b59d0$0$22470$afc38c87@news.optusnet.com.au...

"Dennis" <noone@nowhere.com> wrote in message
news:SL2dnT1wIuUttaTQnZ2dnUVZ_oednZ2d@westnet.com.au...

"Metro" <Home@home> wrote in message
news:4d392084$0$15070$afc38c87@news.optusnet.com.au...

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...
I've a problem with a truck failing to start after 5 days sitting
idle - completely flat batteries, no ignition lights, no
"click-click-click", nothing.


The electrical sytem is supplied by 2 x 12V batteries. These are 21
plate, 800 CCA big lead acid units, each larger than a large 4WD
battery. The charging system works fine with over 28V at fast idle, and
around 26 at idle. It starts fine after a couple of days sitting idle.


I've measured the standby current draw from the batteries with
everything switched off at around 150mA. As far as I can tell the
standby current mainly goes into the remote entry system and a 24/12V
converter.

From my rough reckoning, 5 days @ 150mA = 120 x 0.15 = 18A.hr which
should have bugger all effect on such large batteries.


Comments or suggestions???

Thanks.

Just a thought . Any clocks or timers hooked up/? Is there a back-up
alarm battery for you security flat and attempting to charge
continuously. Any GPS type that regularly transmits reports. You never
know. Silly things cause silly faults.


No GPS or alarms. Vehicle has 3 ECU's, a couple of 24/12V converters and
a remote access door controller. Leakage current drops back in steps to
around 150mA then seems to be stable. I've decided to take it back to the
manufacturer Monday and let them sort it out.....

thanks

I'll bet it's something silly albeit annoying. Let us know the outcome.
It's intriguing................

Will do.

The manuf has told us that there is a "spare always on tail light" that
should have had the supply fuse removed. This sounds very odd, and would not
explain the total flattening of the batteries over 4 or 5 days as the static
leakage current is only ~ 150mA. For what it's worth, the vehicle starts off
as a bare FD230 truck chassis and is fited with coach body + some
electrics/hydraulics.

 

[Metro]

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...
I'll bet it's something silly albeit annoying. Let us know the outcome.

8<- - - - - - - - - - - - - - - - - - -- - - - - -

It's intriguing................


Will do.

The manuf has told us that there is a "spare always on tail light" that
should have had the supply fuse removed. This sounds very odd, and would
not explain the total flattening of the batteries over 4 or 5 days as the
static leakage current is only ~ 150mA. For what it's worth, the vehicle
starts off as a bare FD230 truck chassis and is fited with coach body +
some electrics/hydraulics.

Agree very odd. Did you find this ' tail light ' and the fuse for it?

I have mentioned you prob to a couple of auto mates. They're mystified.

 

[Dennis]

"Metro" <Home@home> wrote in message
news:4d3f6865$0$5004$afc38c87@news.optusnet.com.au...

"Dennis" <noone@nowhere.com> wrote in message
news:-qWdnaigsqgbSavQnZ2dnUVZ_uydnZ2d@westnet.com.au...
I'll bet it's something silly albeit annoying. Let us know the outcome.

8<- - - - - - - - - - - - - - - - - - -- - - - - -

It's intriguing................


Will do.

The manuf has told us that there is a "spare always on tail light" that
should have had the supply fuse removed. This sounds very odd, and would
not explain the total flattening of the batteries over 4 or 5 days as the
static leakage current is only ~ 150mA. For what it's worth, the vehicle
starts off as a bare FD230 truck chassis and is fited with coach body +
some electrics/hydraulics.

Agree very odd. Did you find this ' tail light ' and the fuse for it?
I have mentioned you prob to a couple of auto mates. They're mystified.

No, I left it for the guys who built it. We pick it up later this week. I'll
let you know what they say...

 

[Clifford Heath]

On 01/23/11 13:54, Dennis wrote:

The manuf has told us that there is a "spare always on tail light" that
should have had the supply fuse removed. This sounds very odd, and would not
explain the total flattening of the batteries over 4 or 5 days as the static
leakage current is only ~ 150mA.

Nothing you've said indicates definitively that the batteries were fully charged to start with. Were they? How do you know?

 

[Dennis]

"Clifford Heath" <no@spam.please.net> wrote in message
news:4d4062dd$0$3034$afc38c87@news.optusnet.com.au...

On 01/23/11 13:54, Dennis wrote:
The manuf has told us that there is a "spare always on tail light" that
should have had the supply fuse removed. This sounds very odd, and would
not
explain the total flattening of the batteries over 4 or 5 days as the
static
leakage current is only ~ 150mA.

Nothing you've said indicates definitively that the batteries were fully
charged to start with. Were they? How do you know?

You are correct, mitigating factor is that vehicle had been running ok for 5
weeks, albeit it only stood idle for 2 day weekends.

I gave it an 18 hour battery charge prior to returning it to the
manufacturer.