Identifying ghost loads draining the battery

[TobyQuest]

Hi,

Is it a normal thing that the leisure battery gets drained when not in use?
Im imagining its either a ghost load or the battery is not too clever, even though its only 3 months old.

I have only one single 100AH leisure battery at the moment.
It charges to a maximum of 12.8v, but then each day it drops around 0.1volts when everything is switched off, even including one main switch controlling all the habitation stuff.
So 100% charged is 12.8v and 30% charged is 11.8v it means each 0.1volt drop equates to a 7% loss, so in less than a week the battery has lost half of its charge and as a lead acid battery therefore lost pretty much all of its usable charge.

7% per day losss = 7amp hours which is (x12volts) 84watt hours per day Im losing.

Is this a normal thing in the MH world? If not, how can I find out whats causing it?

 

[busbuddy]

Disconnect the battery first and see if it still drains down, if it dont then reconnect and go hunting with a multi meter for what is live after the off switch......
.radio, tv booster, light, etc

 

[Two on Tour]

Here's a video that will give you information on how to test for parasitic draw on your battery, although this is testing a car battery, it is the same principal for your leisure battery.
A search on YouTube will bring up many more videos on the subject.

 

[poppycamper]

Interesting post as I suffer the same.. I have a battery monitor and with everything switched off the discharge from battery is 0.1A.. does not sound much but that is 2.5A over 24hrs.
I have checked battery leads with a clamp meter and it agrees.. discharge 0.1A.

 

[Richard n Ann]

Ours is 2ma with the main switch off.

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[Two on Tour]

Interesting post as I suffer the same.. I have a battery monitor and with everything switched off the discharge from battery is 0.1A.. does not sound much but that is 2.5A over 24hrs.
I have checked battery leads with a clamp meter and it agrees.. discharge 0.1A.

When you say everything switched off, does that include your control panel as they draw current when everything else is off.
Is your MH fitted with a tracker ?

 

[poppycamper]

When you say everything switched off, does that include your control panel as they draw current when everything else is off.
Is your MH fitted with a tracker ?

No tracker and main switch on control panel switched off

 

[Garfields]

Radio can be the culprit
Often wired to leasure batteries for use when parked
If not wired correctly you are in effect just turning off the screen when you hit the off button
They need a small amount of power for memory but if done wrong they can use a lot more
Worth checking if there is a decent draw on the battery

 

[the1andonly]

TobyQuest you might also have original Japanese boxes hidden somewhere, eg toll system or satnav. On my bongo i discovered a huge satnav box under my middle seats which was still connected even though id removed the head unit.

 

[TobyQuest]

Ive been round pretty much the whole van as Ive done a lot of different work on it. I removed any boxes like sat nav, toll gate thing etc and in any case these were wired to the engine battery.

My radio is wired to the engine battery too as it doesnt turn on without the ignition.

Good suggestion to test if the battery loses voltage when disconnected completely. I will try that.
I have a black box which is a battery isolator between the engin and leisure battery. Potentially if i didnt understand how that works or its in fact not working as it should then perhaps a high state of charge on the leisure battery is being transferred across to the engine battery, but I imagine these isolator boxes arent built in a way that that could ever happen.

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[TobyQuest]

For the last 3 days ive disconnected the battery and checked the voltage each day and its been constantly 12.35v.

Following the instructions of the video above ive disconnected my negative and ran the multimeter in series and its still coming up with zero A, mA and so on, so go figure.

 

[TobyQuest]

OK UPDATE:
Turns out the fuse was already blown in my multimeter.
So when everything is switched off the batter only has a drain of 30mA which is perfect.
When the switch panel is on it uses 300mA, which I think is a little bit on the high side.
I have one of these switch panels: HERE

So over a 24 hour period it means drain of 7AH, nevertheless everything is switched off ususally including this switch panel so it remains a mystery.

Once I have finished installing my battery monitor I will have a better idea of things.

 

[irnbru]

What about an alarm, that might be causing it.

 

[TobyQuest]

What about an alarm, that might be causing it.

Good point. I'll arm the alarm and test the draw.

 

[Phill D]

12.35 v is only around 70% charged. i have in the past connected up to neg to measure current draw then 1 at a time removed each fuse ( assuming you have a fused panel on the habitation ) to watch the change.
that has found the culprit for me,

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[TobyQuest]

That's right, it's 70 percent charged but about 60 percent of its ideals charge is already depleted.
I will try pulling fuses too. I do know theres something dodgy with the electronic flush on the toilet. It doesn't work and when I press it momentarily the cabin lights dim

 

[pappajohn]

12.6v is the float voltage of a battery.
Charge voltage should be 13.6v+...
Discharge the battery by turning on lights etc for an hour with charger turned OFF (off hookup) then turn charger on and recheck charge voltage. If its still 12.8v the charger is at fault.... Or Noah was the last to use it.
At 12.8v the battery isn't receiving a full charge.

 

[TobyQuest]

12.6v is the float voltage of a battery.
Charge voltage should be 13.6v+...
Discharge the battery by turning on lights etc for an hour with charger turned OFF (off hookup) then turn charger on and recheck charge voltage. If its still 12.8v the charger is at fault.... Or Noah was the last to use it.
At 12.8v the battery isn't receiving a full charge.

I think you misunderstood the topica bit. Because 12.8-12.9v is the voltage of the battery when its fully charged.
Im not using any battery charger. When the battery is being charged by the alternator the voltage is 14.1 and by the solar panel 13.1 approximately. But the topic is that the voltage is dropping quite a fair bit over a number of days and its not clear whats causing the drain.

 

[TobyQuest]

Well after some more testing these are the results:
When everything is off theres around 25mA draw = Great
When the mysterious black box is on there's a 310mA draw = Not ideal

Of that 310mA draw, 25mA is the natural draw as above anyway, 35mA is for the diesel heater, 10mA is for the battery voltage monitor, 20mA is for the LED switch panel, the remaining amounts I expect are spread approximately evenly between the other appliances and the black box itself.

It still doesnt explain why its draining, unless firing up the black box itself uses a large amount of energy.
My next test is to fully charge the battery, not use anything, but keep everything connected and test the voltage each day thereafter.