12v electrics

Hello, hope you are all keeping safe. I have a problem on my 08 Nuevo EK to do with 12v electrics. When I am on EHU no problems, when not on hook up with a fully charged battery and I leave MES panel on, the battery flattens overnight. When I turn panel off overnight the battery maintains charge. Have been around all appliances and lights several times but, nothing on. Any suggestions gratefully received. Battery has been tested and is good.

My battery was draining quickly with the MES panel left on. After lengthy investigation I finally found that my battery charger had a switch for float or charge which was set to float giving 13.8v max. When switched to charge it gives 14.4 and the battery gets a much better charge and so lasts longer. According to MES instructions the panel draws 110 mA when asleep but it doesn’t tell how much when on.
My charger is a muvonics standalone box under the passenger seat

Cymro wrote:It must be something beefy to drain the good battery.

Agreed - some simplistic maths (based on the assumptions: 80Ah battery, "overnight" = 12 hours) means a drain of 7 Amps, all the time, for 12 hours. Generally anything taking that much power for that long will be getting quite warm! A typical A/S conversion has very few appliances that can consume that much power under normal circumstances - the fridge 12V element (which obviously should not be powered from the battery) and tank heaters. That's about all that I can think of.

Battery testing is not an exact  sciance , sometimes the resuls are misleading  .my  nuevo  2014 has an amp meter  in the controle panel  showing amps  charge and discharge  ,

Thanks for suggestions so far, the problem started about three weeks ago in the Hebrides. I have owned the van for around seven years and always left panel on without problems. I have a110 ah battery which has performed well and less than two years old. When parked on drive previously with the panel on the solar has kept it fully charged.

Perhaps it would be idea to check solar panel and controller, output  ?. Also solar  harvest drops considerably  this time of  year , I have fitted a battery monitor  that supplies  all  the battery  and charging information i need , Victron bmv  is one example  , cheaper ones are availability

Hi Stoneman.

Have you found anything yet? I live in the same area if I can help. Although we are on lockdown again in Monmouth.

Hello Gollum, thanks for reply, not sorted problem yet. Maybe we can get our heads together after lockdown.