bootlucy Posted February 8, 2018 Share Posted February 8, 2018 Hi, just bought a 6 watt solar panel battery maintainer to help keep my leisure battery topped up. Does anyone know if it will charge the leisure battery on my Bailey Advance m/h if I plug it into the cigarette lighter or will I have to connect it directly to the battery ? Link to comment Share on other sites More sharing options...
Keithl Posted February 8, 2018 Share Posted February 8, 2018 The answer to your final question is No and Yes. Plugging into the cigarette lighter will not charge your leisure battery so it will have to be connected correctly. And now for the bad news, IMO this panel will not achieve what you want. 6 W is only half an Amp at 12 Volts and that 6W is maximum output probably measured on a nice bright sunny day. At this time of year it will deliver next to nothing! Over the course of 24 hours in winter you may harvest possibly one amp hour which is not worth the effort you are going to. From reading other posts on here you probably need at least an 80 W or even 100 W panel to keep your battery truly charged. Just my views you appreciate. Keith. Link to comment Share on other sites More sharing options...
bootlucy Posted February 8, 2018 Author Share Posted February 8, 2018 Thanks for that, Keith. I thought it might help to keep a charge while m/h is parked up between trips as we always go for ehu when on site. Link to comment Share on other sites More sharing options...
Charles Posted February 8, 2018 Share Posted February 8, 2018 If you don't have any parasitic drain on the battery and prop the panel up at 45° facing the sun it will keep the battery charged. Don't use a controller though as they take power. And there needs to be a diode in series to stop the battery discharging at night. Link to comment Share on other sites More sharing options...
747 Posted February 9, 2018 Share Posted February 9, 2018 I still have a 12 watt solar panel that I used for the engine battery on a van I used to own. I had to modify the Cab cigar lighter to permanent live and plug the panel in to it. It certainly made a difference. A solar controller is not needed for any panel up to around 30 watts output. Solar Panels come supplied with a blocking diode so there is no drain from the battery. Link to comment Share on other sites More sharing options...
bootlucy Posted February 9, 2018 Author Share Posted February 9, 2018 Thanks for all your help, panel bought from Halfords and seems to be a quality product and it has the blocking diode so we'll see how it goes. Link to comment Share on other sites More sharing options...
bootlucy Posted March 18, 2018 Author Share Posted March 18, 2018 Hi, just to update, connected panel directly to battery and after a month the control panel reads 12.8 volts so it seems to be working as the battery would have dropped before Link to comment Share on other sites More sharing options...
aandncaravan Posted March 19, 2018 Share Posted March 19, 2018 Bootlucy, did you check the Control Panel in the night or during the day? If it was during the day the Control Panel will be displaying the Solar panel charge voltage, which is not usually the battery voltage. The real battery voltage may be much lower. To demonstrate this, start your engine and watch the 'Alternator charging' raise the habitation battery voltage to 14.4v. Then try and use the display to 'see' the batteries previous 12.8v and you will find you can't. All you will ever see on the Voltmeters display is the voltage at the battery terminals, which clearly isn't the same as the battery voltage. Also, most batteries will hold an artificially higher voltage than their real one when first taken off charge, so you need to wait a few hours after charging is removed to allow them to settle down to see the batteries real State Of Charge (SOC). That is why when checking a batteries SOC, it needs to be done several hours after any charging has ended, in your case several hours after sunset. Many people make the same mistake, believing the battery is more charged than it actually is because they see the higher charging voltage of the Solar during the day when they are in the vehicle. Read some of the threads on here from those with Solar panels and you will hear the same, "my 100w Solar is brilliant, because after running the TV all night the battery is up to 12.8v by 10:30 the next day", when the battery probably isn't. They are just seeing the Solar Regulator's voltage at the batteries which is probably still down at a discharged 12.2v. A 6 watt Solar Panel might be able to deliver a theoretical maximum 0.5amps on a Sunny day in the middle of June, but behind a Vehicles Windscreen, mid March on a typical Spring day you will probably get less than 0.1 amp? I would suggest that if you check the battery SOC at midnight tonight, it might not be that different to what you saw last year. It will depend on the battery you have and the setup. These days most quality batteries won't Self Discharge but old fashioned technology batteries like the Banner wet Energy Bull range do self discharge a lot more than the best batteries. If you have a quality battery fitted, it is often more effective to isolate the battery by removing the battery Negative lead than it would be to just put in a tiny Solar Charge. Link to comment Share on other sites More sharing options...
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