Hi Guys
I have a Swift Eccles 580 , I've only had it since March and never used the panel off grid.On my other vans I used to leave the EHU plugged in throughout the winter .
My question is will the panel charge the battery through winter without the need to plug in the EHU.
I checked the battery level today and it's showing 12.2 v.Is this normal for winter as sun and light is to a minimum.
Difficult to give an absolute answer, as a bunch of variables that we are unaware of, like do you have any current drain on the battery from alarm or tracker, is the panel in the shade at all, what type of charge controller fitted (some are better than others in low light conditions) etc.
Solar panel performance plummets in the UK winter due to short daylight hours, low angle of sun, overcast skies etc., so at best it will only give typically around 15-20% of it's rated output (150W = 20-30W), for maybe 4-5 hours a day, which is ample to give a maintenance charge to the battery if no great discharge load on it.
Alarms and trackers generally only draw fractions of an amp, but do so 24 hrs a day, so the solar panel has to compensate for that drain in only a few short charging hours of daylight a day, so that's where the issues can occur, and the balance can be quite close, the battery is unlikely to discharge completely to damaging levels, but may not be fully charged during particularly dull periods. It may need a 'proper' charge occasionally to keep in tip top condition.
I've got a 'temporary' small solar panel fitted in a skylight to keep my battery topped up in storage (the alarm would flatten it!), it extends the time I can leave the battery unattended from maybe a couple of months to 3 or 4 months at a time, so it certainly makes a difference and my panel is much lower powered than yours.
Every possibility your panel will do the job just fine, you just need to keep an eye on the battery to ensure it isn't becoming too discharged, after a while, you'll be able to tell if panel doing the job well enough and relax your checks on battery. The inbuilt battery state meters in caravans are pretty inaccurate, far better off with a proper voltmeter (multi-meter on V setting) used direct to battery terminals.
Your 12.2V reading appears to be a little low, but could be in part a reflection of cold weather. Ideally it should be 12.5-12.7v when fully charged. Useful bunch of info here on battery voltages: https://carbatterygeek.co.uk/car-battery-voltage-chart-uk-12v/
I have 100w on the roof and I need to plug the caravan into the mains during the darker months, however my caravan is in the shade most of the day due to houses blocking the low sun.
I have a 100watt panel on the caravan roof with a Truma smart controller which acts as a smart battery charger. I don't need the mains at all and the battery is always fully charged. The van is always parked in the open so no real shading of the panel and the panel is laid flat on the roof.
I get the van serviced in early Feb which means a lot of mover use getting it in and out of the drive. The battery is always fully charged a day or two later.
Generally the winter output for a solar panel will be about 10% of summer output.
I don't have any discharge such ass alarm, fridge, TV aerial controller etc.
Quote: Originally posted by navver on 13/12/2023
I have a 100watt panel on the caravan roof with a Truma smart controller which acts as a smart battery charger. I don't need the mains at all and the battery is always fully charged. The van is always parked in the open so no real shading of the panel and the panel is laid flat on the roof.
I get the van serviced in early Feb which means a lot of mover use getting it in and out of the drive. The battery is always fully charged a day or two later.
Generally the winter output for a solar panel will be about 10% of summer output.
I don't have any discharge such ass alarm, fridge, TV aerial controller etc.
Agree 100% with this post I could of written it myself as we also have 100W. Previous caravan had a 20W and this also kept battery charged all winter.
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