Flat batteries in new campervan.

Our trailer caravan is parked by the house in full daylight. The built-in control panel gives us much information on power supplies and levels. I note from this that at this time of the year the solar panel on the roof gives rather a poor output, presumably because of poor winter light levels. We always keep the mains cable plugged in as there are systems on board which will otherwise deplete the battery which is at a steady 13.6v. 

As you are using a MH, the on board systems will have an even bigger draw on power so if it’s not being charged by normal usage the battery will deplete. My BMW tow car wasn’t used much this year and I had to resort to connecting a battery charger to it once or twice because on-board systems which were not obviously turned on but work in the background started to deplete the battery.

Suggest you connect up a mains lead to your vehicle, -which will protect against battery depletion. The power consumption of an on-board battery charger is very small, particularly once the battery is fully charged. 

Could it be they have taken to using one of those new style Lithium~ion thingies, they are a different size & shape to those like what ABM is used to   ?

We are in Fife and have been monitoring our starter battery very frequently in the gloom of the Scottish Winter. We have a Lithium Leisure Battery that will charge to 14.2v before the Battery Relay kicks in fully [waiting for an appointment to get an Ablemail AMT 12-2 Battery Relay fitted that has specific Lithium settings for both Smart & Standard Alternators, and will feed the starter battery from the Lithium battery in 15 second pulses of up to 4 amps, leaving the latter to then recharge from the 180w Solar Panel

Over the last week, we have had 1 day where the Solar generated 20wh, 2 days where no solar input occurred, and 4 days of 10wh, so the Lithium is struggling to exceed the threshold at which it can feed the starter battery [and we have turned off the alarm and interior cab lights to minimise power consumption]

We have been taking the motorhome for a 25 miles run about 3 times per fortnight to keep the new Yuasa 930 amp Cold Cranking Speed starter battery charged. By Day 5 or 6, the reading from a multi meter is down to 12.5v. The auto electrician who fitted the new battery and tracked down a parasitic backfeed charge from the starter battery after the earlier battery failure destroyed the airbag ECU said that he would leave the starter battery for a maximum of 2 weeks before recharging it, but with the low Solar input and a maximum of 4.5 hours power generation each day, I won't leave it longer than 6 days between 'recharge runs'

Steve

 Having spent 4 or 5 winters in Rosyth I can vouch for the lack of sun in Fife .... Did many 'Divisions' in sub zero temperatures 😉 I spent a winter chiselling an inch of frost from my car before I could begin to see out of it.

 Well a similar problem occurred with the " Concorde" last Thursday as i'm going away to 'Blackhorse Farm' , when i tried to start the vehicle !! Despite being on 240v for a week's trickle charge !! A call to the R.A.C initiated a very experienced mechanic ,who spent a good two hours diagnosing and rectifying the problem (good man !! ) My monitor panel was only showing 11.4v on the engine battery (despite the hook-up) Leisure batteries feeding the starter battery were down to 12.4 (trying to feed ) a dead battery.

After ALL the tests and investigations ,yes the 5 year old engine battery was DEAD .So off he goes to Canterbury for a new item,£175 ,,,,plus 5 year warranty. .Alternator  charging O.K .BUT ,but during the refit discovered that there was 'sparking' from the EARTH clamp !! 

It now appears that the last time the other battery was fitted ,the cable/clamp connection was left LOOSE !!  This would obviously attribute to some of the previous problems that I've been experiencing !!  Now ,however (fingers crossed) all seems fine !!

Moral of the story ?? ,,,,,CHECK your connections !! ,,,.

We're in 'sunny Burntisland', where the sea is gunmetal grey, and the wind is whistling off the Forth, across the Links, and right through our doors! Being 100m from the sea is lovely on occasions, but today is not one of them! The Solar Panel did produce a 'December best' of 30Wh yesterday after a late burst of sun, but today's counterbalance is a zero contribution. Must start the Motorhome tomorrow, but will wait for the 'Systems Check' Lights to finish their routine, because, if the starter battery is too low, the instrument panel Airbag Warning Light will remain lit, apparently, offering the chance to run an extension lead across the footpath [with H&S rubber matting trip hazard protection] for an EHU top up charge. Starter battery was 12.5v at close of play yesterday, so hoping that the level tomorrow will still be in the safety zone!

Steve

CAREFUL With that Triky Mate :--  the last time I tried to check My connections I got my face slapped     !!

 Oh ,too much " Touchy Feely " ?? .

A couple of points....firstly, a poor earth strap chassis connection is a known issue for causing low (flat) vehicle battery levels....a simple check and fix...

secondly, no matter how you cut it, if a cab battery receives less power than it gives out, it will go flat...and with modern MH systems and tracker/isolators this can take as little as 2-4 weeks...seems shocking to a new MH user but it's how it is.

so, how do we ensure the equation is balanced in our favour...easiest solution mentioned many times is to plug the van into the mains provided the van has a charger/system for charging the cab battery.

secondly, a decent solar set (100w-150w up) with a twin output controller 'should' be enough to keep everything healthy.

relying on running the engine isn't a real solution as ED mentions above.

I live in the 'sunny' south and my previous 100w panel with cheap PWM twin charging controller managed this in all but prolonged periods of deep gloom...but as we were never home long enough to let this happen, all was fine...mains there as back up.

we now have 300w and a flashy new MPPT controller which does all manner of things, but at the end of the day you just need a tiny bit more going in than goes out to be a happy camper.

We fitted a Lithium Leisure Battery to remove 'range anxiety' when we are not on EHU but have moved the anxiety up the line. We have 180w Solar that feeds the Lithium and a VanBitz Battery Relay that is supposed to top up the Starter Battery. Unfortunately, the Relay doesn't cope with Lithium very well.

The Lithium starts to enter Float Stage at 13.5v and the Relay should kick in at 0.7v lower reading on the Starter Battery [in practice, it can be as much as 0.85v lower], so that requires the Starter Battery to be as low as 12.5/12.65v and a teaspoon of charge result in the Lithium going back to sleep [the 4 weeks old Starter Battery has fallen to 12.48v over 8 days, and looks to have 'bottomed out' at this figure]. I've run a mains connection across the footpath today to get the Starter Battery back up to 12.7v but this will be a temporary solution until I can rearrange an appointment to get an Ablemail AMT 12-2 Battery Relay fitted [2 Lithium Profiles for Smart and Standard Alternators]. The AMT 12-2 takes a 'Start of Day' charge of up to 4 amps from the Lithium and transfers it to the Starter Battery in 15 second pulses, leaving the Lithium to be 'refilled' from the Solar Panel during the day

Steve