why does the battery on my ford cargo 0811 keep discharging?

Hi, Anna - Charge your battery and leave it off the vehicle for a couple of days then check the voltage if it's not showing 13.5 - 14 volts then the battery could be no good take it to your local battery dealer and get them to check. You could fit the charged battery on the vehicle connect the earth lead and test with an ammeter between the battery positive terminal and the positive lead to see if any current is being drawn; if it is and everything is switched off you have a circuit problem - send for the auto electrician. As you have leasure batteries you must have living quarters - check the ZIG unit switches are in the correct positions, if they are not the batteries get gobbled up including the main battery. Do you have an alarm fitted? - that draws current at all times and will discharge a poor battery quite quickly. Lastly - should be first really -check the acid level in the battery and top up if necessary so as to just cover the plates - distilled water only. Given time you will come to understand the love hate relationship of the 0811 owner and the electrics associated with the horse box conversions! Just noticed it was posted in December 09 so I'm probably a bit late with an answer

DDA
June 2010

You're welcome Multi-X.
What makes you so sure we're all lads there AS?

JD
December 2009

now lads lets calm down .
i think that the lady will love you fighting over her but it will not fix her horsebox .
it could be that the batteries should be cherged up then left standing for a couple of days and tested without being fitted that would eliminate them.

as
December 2009

dear jd i am a fully qualified auto electrician
but thanks for youre insight into electrical current flow and ohm law xxx

xxxxxxxxxxxxxxxxxxxxxxxxxxx
December 2009

In response to XXXXXXXXXXXX (which presumably stands for: HAVEN'T A CLUE)
If current flowing to earth is less than rating of the fuse protecting that circuit, then clearly that fuse will not blow but battery will still be run down.

JD
December 2009

make sure heaters etc are all switched off ,
i am a little bit confused when you say 2 batteries in the living area these should be wired in parrallel to produce 12volts as that is what the voltage of an 0811 is .
but i dont think it is a positive going to earth as previously suggested that would blow a fuse or cause a fire

xxxxxxxxxxxx
December 2009

Other thing to check is your alternator. If it is defective, the battery will not be charged and will definetly go flat!

JD
December 2009

There is a short to earth somewhere. Despite everything being apparently switched off, there may be one of more circuits where a positive cable is touching the chassis or bodywork. Common problem where "gadgets" or accessories have been added and subsequently removed without disconnecting wiring properly. Can also be due to chafing of cables on sharp metal egdes where extra cables for accessories have been run carelessly. If insulation is worn off by chafing, then bare conductor can touch chassis (and remember the chassis is connected to the battery negative terminal - i.e. negative earth).It could be more than one item causing the problem. The easiest solution is (a) disconnect your negative lead when you park the truck or (b) fit a battery master switch which does the same thing but is more convenient.

JD
December 2009