Leisure battery draining????

Hi folks.
We're out in our mo home and after one night, using very little power/lights, our pump stopped working, the lights barely come on and the display panel shows that there is no power in the battery. I started up the engine for 2 minutes, turned it off again and now the panel shows a full  leisure battery and pump etc all working. I am assuming that the solar panel isn't charging the leisure battery but unsure as to how I can test the solar panel? We are in a 1999 peugeot boxer classic autosleeper. Any genuine advice would be more than appreciated. Thanks.

How much charge did the battery have at the start of your trip? If recently fully charged then the battery may be on its way out? At this time of year the solar panel won't be doing much (low sun and cloudy weather). I presume you are not on electric hook-up? Running the engine for just 2 mins won't put much power back into the battery. If possible, get onto hook-up and give the battery a good long charge.

Hi thanks.
I should have added that we live in Spain so plenty sunlight all year. The battery was showing full when we left home yesterday. As you say it could be the leisure battery itself. We've had the battery 2 years.

Check this please....

Disconnect the -ve wire from the solar controller.
Use a multimeter, set to 200vdc to measure the voltage of the panel, in good light.
Now set the multimeter to 10A, and swap the red cable to the 10A connection on the multimeter.
Now check across the removed -ve solar panel cable and the +ve one still attached to the solar controller.
Record all readings.
Now reconnect the solar controller -ve wire so all is back to normal.
No idea what panel you have but lets say its 100w.
You may have a data sheet for it, or if you know its make go online and get one.
I'd expect circa 20 to 25vdc from the first test, the panel offload voltage
I'd expect anything between 2 and 4 amps from the second test, it'll be very light dependent.

So, assuming that all looks reasonable, now do the following.

If you can, remove the LB from the van and connect it to a battery charger, mains, and leave it for at least 12 hrs, you won't overcharge it, the charger won't let you.

Disconnect everything and leave overnight.

Now set the multimeter to 20vdc and measure the battery voltage.
If a good battery it should be 12.7 to 12.8v.

If so, refit it to the van and use some lights or tv whatever for an hour or 2. If a sunny day, the solar should easily power all those and the LB voltage should be, if anything, higher as its being charged by the solar, even though under load.

Now switch everything off and, when totally dark, measure the LB voltage again.
If 12.7 to 12.8 then the battery is probably OK if less then its suspect. The only test that can now be done needs a tool the battery shops have so take it there and get it checked using their loading tool.

Most likely cause,,LB but not placing bets!

Now that's the kind of knowledge I wish I had Ian H lol. Many thanks for that. It'll be next year before I get an opportunity to do these tests but I'll put a reply on here with the results. Thanks again. Have a good new year.

Sounds to me like a dodgy battery connection.  Check the terminals and the battery fuse.

It turns out that the battery is charging through the day but loses power as soon as the sun goes down

Well that's a start!
It tells me that the solar is charging, did you measure the battery voltage in good sunlight, should have been circa 14v or so?
If so then solar is good. By disconnecting the +ve terminal we also isolate the solar panel from the battery
Therefore as there are really only 2 components, the battery is suspect.
As I suggested above either remove it to a bench or simply just remove its +ve terminal. Connect a car battery charger to it from a mains source, do NOT have the EHU connected or switched on, we need just the car battery charger on its own. In this way there'll be no solar input or vehicle charger input to the battery.
Leave it all day, then disconnect charger, leave everything else alone.
Next morning, measure the battery voltage (still has +ve connector disconnected remember).
It should, if properly charged the previous day be 12.7v +/- 1 or so.
Try that and see what results you get.

Thank you Ian. I'm going to check everything tomorrow.

The battery is disconnected, is on the work bench and attached to battery charger. 
On the assumption a new battery is required, do most folks prefer agm batteries, lithium batteries, open or sealed lead -acid?

Anything other than Lithium, due to charging considerations and, a price similar to a small country's GDP!
SLA for me, zero maintenace and very small spill risk.

If you need a new battery have a look at the new lead carbon gel batteries, these can be discharged further than lead acid ,faster charging  than lead acid and can be left partial charged longer than lead acid, they are a little dearer than normal lead acid but nowhere as dear as lithium, your solar and battery charger will not need replacing either

Thanks Freelander