Battery Puzzle

Apple wrote:Whilst off grid last weekend my low vehicle battery went off after 2 nights. I checked the gauges and the vehicle battery gauge was showing marginally under 13v, the leisure battery showing 14+ volts. The van started and everything was working as it should. 

It's now been parked on the drive for the last week without an electrical hookup and on going to the van this morning exactly the same thing happened again with everything working correctly. The vehicle battery is only 1 month old, I don't know the age of the leisure battery but as seen from the photo the green stripe would indicate that it's OK. I measured the voltage across the terminals and the result matched that of the Sargent display in the van

Would be grateful if anyone can offer advice as to why the low vehicle battery alarm is sounding and possible remedy. This fault does not repeat when on EHU.

Many thanks for any help and apologies for my photo editing skills as try as I may I can't turn the battery photo through 180 degrees

handiyman wrote:
I had similar issue. Turns out battery fuse was blown and high voltage reading is of incoming solar voltage which is higher. 
Also if you have an autosleeper van why have you got a lead acid battery as Autosleeper says they only supply Lithium Ion batteries. See page 9-10 of owners manual.

FreelanderUK wrote:


His van is 2013 so we’ll before the dat AS started fitting Lithium batteries

handiyman wrote:

I thought I read the battery was 1 month old ?

handiyman wrote:
I thought I read the battery was 1 month old ?

Paulmold wrote:
People do replace knackered batteries.

handiyman wrote:
Ok, sorry I spoke

Alan Wilkes wrote:I would check the battery voltage with a voltmeter and check it at the battery terminals. If it is low then you have a problem. I would charge up the battery at home and then disconnect it for  couple of nights and then check the battery voltage again at the terminals. If it is low then it is faulty, if it is still high then there is somthing discharging the battery.
Charge it up again and with the battery connected turn off everything in the MH and wait for 2 days then check the battery voltage again if it is still high, switch on each appliance one at a time wait 2 days and check the voltage and keep doing this to find out what is discharging the battery. The vec Battery should not discharge whilst you are parked up.

Alan Wilkes wrote:Hi Chris
I am a Boxer AutoSleeper Symbol owner. The Charging system had modified by an "Expert" and could, and did, discharge the Veh battery. I converted it back to original and repaired it. My system is now fine.

Happy Camping
Alan

Aethelric wrote:During the day you will be. charging from the solar panel(s).  Your leisure battery looks like a fully charged battery (maybe even over charged) on charge.  Your vehicle battery looks like a partially discharged battery on charge.

 
PLAESE NOTE
Just because the leisure is showing 14.9 will not say it’s fully charged it’s the charge voltage from the mains or solar.charge .to test a battery voltage needs to have been taken off charge for a time a let stand 


The leisure battery probably has had zero discharge since the last time it was charged - i.e.yesterday on the solar panel.  The vehicle battery would have had a small amount of discharge overnight due to the radio, remote locking circuitry etc.

You don't mention the type of vehicle battery. 
If it is a flooded lead acid the open circuit terminal voltage will be around 12.6V. A gel or AGM battery will be around 0.2V higher.

NOTE the voltage will be 12.7 to 12.8 if fully charge and in good condition 

Maybe the Sargent is expecting a different type of battery to what you have fitted and it's dipping below the alarm trigger voltage overnight.