Solar battery charger

[afandy]

Are these worth buying?....my hook up has only ever charged the habitation battery's so have to charge up my engine battery seperately ..which is awkward ....

[Wooie]

Hi there.

 

You need to put a bit more info than just " Solar Battery Charger " as there are many different

types and models out there.

 

Is it wanted to just charge the Engine Battery or the Leisure Battery as well ?

 

Do you want Free Standing or Fixed solar panels ?

 

Then someone will be along shortly to help out.

[spospe]

A solar panel will always put some charge into a battery, but to charge one from flat is quite a big undertaking, especially at this time of the year.

 

I suspect that you may be asking for advice on maintaining a fully charged battery and this is a much easier thing to do with a small panel.

 

Using a panel of up to about 20 watts rating, you will not need a regulator, over 20 watts you will (to avoid over-charging the battery).

 

Remember that a nice new battery will easily hold its capacity for several months without any form of charge (unless it is being called on to run an alarm system). Our car stands for up to 8 weeks whilst we are away and we have never had any battery problems.

 

My personal advice is not to bother unless you are having real difficulty starting your van after a long period of inactivity.

 

From past experience, this question can easily turn into a long thread with many addendums as each answer sparks another question.

 

 

 

[colin]

At a guess you want to use it to keep charge in vehicle battery during long periodsof inactivity over winter?

[Mel B]

Hi afandy - welcome to the 'play pen'!!! (lol)

 

On a previous motorhome we used to use one of the small type of solar panels that I think you are referring to like this one:

 

http://productwiki.co.uk/maplin/alternative-energy/12v-24v-13w-solar-suitcase-13w-solar-suitcase-wiki/228539N80GT.htm

 

It plugged into the 12v socket on the dash which, fortunately, remained lived when the engine was off (not all of them do this) and helped to keep the engine battery topped up when it was stood as, similar to you, it didn't charge when on hook-up. If your 12v sockets aren't live you'd need instead to have a link to the battery itself, not difficult though.

 

The alternative is to get a Sterling Battery Master which will link your engine battery to your habitation battery and therefore it will be charged when you are on hook-up:

 

http://www.campervanstuff.com/shop_stuff/index.php?mod=product&id_prd=976

[RogerC]

afandy...we had battery drain problems on our MH when left standing over last winter so bought one of these     http://www.sunshinesolar.co.uk/khxc/gbu0-prodshow/SS15W.html

 

It is on sale right now until the 10 December and is the same price we paid for ours.  We also bought a regulator from them and since buying and using it we have had no battery problems.  Like has been mentioned though you need to make sure your cig lighter socket is live with the ignition switched off and if not get one fitted.  We always fit ours when the MH is parked up in storage.  It fits nicely along the top of the dashboard.  We also use it 'on site' for a bit of 'belts and braces' power.

 

Controller/regulator information is on the solar panel page on the link above.

 

[afandy]

What can I say great answers ...yes I'm after some top up for my engine battery over the winter period of non use ....just say something that could fit on the dash and leave ....good point about the cigarette lighter being live without the ignition on ...thank you very much all of you ...great response .. (lol)

[colin]

In that case the panels given in links above should be ok, or as Mel has posted you could fit a battery master and charge both batteries at the same time, or you could do as us and fit a 80w panel that charges both batteries for extended periods of non use or extended periods on sites without hook up, we like our set up as it's a fit and forget system, but as we store our van undercover it only just about copes in middle of winter.

[jam151]

i have a 40watt panell for my (sorry) caravan, it sits INSIDE the front window & keeps the battery in good condition, the light on the zig unit was red before i connected it, within 1 day the light was green, i bought it from ebay (new) it comes with a regulator cables & crocodile clips i think it was only £80.00 i have been checking it every weekend & the battery is in tiptop condition. it also only needs daylight not sunlight to charge, the regulator shows when it is charging & the condition of the battery, if i can find a link i will post it here if anyone is interested in a look

jamie

[Clive]

I would be tempted to suggest a bigger panel than 40 watts to keep a Motorhome with an alarm system etc in good condition with starter and leisure batteries to maintain in the winter. My normal posture is to suggest a minimum of an 80 watt panel on the roof of the motorhome, a good regulator and a bridging fuse to parallel batteries when the vehicle is laid up for winter. If the motorhome is economical in its use of 12 volt electricity then you should get some electrical independence during the summer months as well as a worry free laying up in winter.

 

(Economical means NOT a compressor fridge and NOT a diesel heater but WITH LED lighting

 

C.

)

 

 

[spospe]

jam151 - 2012-12-04 10:23 PM

 

it also only needs daylight not sunlight to charge,

 

It is true that a solar panel will produce a charge in daylight and that it does not need sunlight, but the ratio is about 1:10. To get any meaningful output from a panel it needs direct sunlight falling on it without any shadows at all.

 

My records, kept over the last 5 years show that a 65 watt panel that can 'see' a clear blue sky will give an output of about 0.3 amps, the same panel on the same day with full sun on it gives about 3.4 amps.

 

Remember, these are peak, middle of the day figures. Forget the three hours either side of sunrise and sunset.

[jam151]

allthough they probably do produce a higher charge in direct sunlight some pannels actually perform worse if they get too hot, i havent had a chance to check what output im getting but on a dull rainy day last week i had a look & both lights on the regulator were green, showing it was giving a full charge (if the daylight is insuffucient the light will show amber) my regulator is just a basic 5amp with variable options to allow power output for 12v i could have a light come on for a set time after sunset for example.

i had a look at some flexible pv panels there lighter & bend to fit roofs on vans bette,r slightly more expensive but supposedly better for fitting permanently

jamie

[spospe]

jam151 - 2012-12-07 6:07 PM

 

allthough they probably do produce a higher charge in direct sunlight some pannels actually perform worse if they get too hot, i havent had a chance to check what output im getting but on a dull rainy day last week i had a look & both lights on the regulator were green, showing it was giving a full charge (if the daylight is insuffucient the light will show amber) my regulator is just a basic 5amp with variable options to allow power output for 12v i could have a light come on for a set time after sunset for example.

i had a look at some flexible pv panels there lighter & bend to fit roofs on vans bette,r slightly more expensive but supposedly better for fitting permanently

jamie

 

All panels have about a 5% drop in output when they get hot (over about 50 degrees C). It is misleading to rely on lights, all my measurements are based on reading the output on a digital meter.

 

There is no 'probably' about it, you need full direct noon sunlight to get anywhere near the quoted output from a panel. No sun = dramatically less output.

[crinklystarfish]

spospe - 2012-12-06 10:17 PM

 

It is true that a solar panel will produce a charge in daylight and that it does not need sunlight, but the ratio is about 1:10. To get any meaningful output from a panel it needs direct sunlight falling on it without any shadows at all.

 

My records, kept over the last 5 years show that a 65 watt panel that can 'see' a clear blue sky will give an output of about 0.3 amps, the same panel on the same day with full sun on it gives about 3.4 amps.

 

Remember, these are peak, middle of the day figures. Forget the three hours either side of sunrise and sunset.

 

0.3A = about 33hrs of daylight to achieve 10Ah

3.4A = about 3hrs of strong direct overhead sunlight to achieve 10Ah

10Ah can be achieved with a modern alternator with about 6 minutes of running the engine.

 

Many people have solar panels; some people need them; most don't.

[colin]

crinklystarfish - 2012-12-08 9:36 AM

 

spospe - 2012-12-06 10:17 PM

 

It is true that a solar panel will produce a charge in daylight and that it does not need sunlight, but the ratio is about 1:10. To get any meaningful output from a panel it needs direct sunlight falling on it without any shadows at all.

 

My records, kept over the last 5 years show that a 65 watt panel that can 'see' a clear blue sky will give an output of about 0.3 amps, the same panel on the same day with full sun on it gives about 3.4 amps.

 

Remember, these are peak, middle of the day figures. Forget the three hours either side of sunrise and sunset.

 

0.3A = about 33hrs of daylight to achieve 10Ah

3.4A = about 3hrs of strong direct overhead sunlight to achieve 10Ah

10Ah can be achieved with a modern alternator with about 6 minutes of running the engine.

 

Many people have solar panels; some people need them; most don't.

 

I would guess that very few people regret fitting a solar panel, I have 12 years experiance of using them on a van and previous to that used them on boats. The one thing I can be assured of is that when I walk up to my van to start it the batteries are always fully charged with absolutly no effort on my behalf, maybe I'm lazy but I just can't be arsed with checking voltages, hooking up if there down or having to run the engine just to keep the batteries charged. I've read so many posts on forums of people having to mess about with batteries going flat over winter when all they needed to do was fit a solar panel.

[crinklystarfish]

Fair enough.

 

Just trying to point out that they are a potentially expensive and faffy solution to a problem that most people might perceive they have, as opposed to a problem they actually have.

 

Way better all round, if possible, to take the 'van out once a month and get everything up to operating temperature.

 

A reasonably sized solar panel might help with maintaining alarms / immobilisers / trackers / other electronic systems, but it won't help with sleepy-van syndrome.

 

I maintain that many have them, but would get along just as well had they not bothered. Each to their own though, it's not meant to be a criticism, just a reality check for anyone about to fork out a decent sum of cash and drill holes in their roof.

[colin]

crinklystarfish - 2012-12-09 9:40 AM

 

Fair enough.

 

Just trying to point out that they are a potentially expensive and faffy solution to a problem that most people might perceive they have, as opposed to a problem they actually have.

 

Way better all round, if possible, to take the 'van out once a month and get everything up to operating temperature.

 

A reasonably sized solar panel might help with maintaining alarms / immobilisers / trackers / other electronic systems, but it won't help with sleepy-van syndrome.

 

I maintain that many have them, but would get along just as well had they not bothered. Each to their own though, it's not meant to be a criticism, just a reality check for anyone about to fork out a decent sum of cash and drill holes in their roof.

 

On the face of it very sensible advise, and we do indeed take our van for days out over winter as I don't like leaving it for too long without a run, but there are vans out there which struggle to start if left one month, ask Eddie! Then you have to factor in work that takes up most of the week, several houses to maintian, all those jobs that sudenly need to get sorted by chrismas, a couple of weeks holiday in the sun, pests that need shooting, elderly parents and young girls that need looking after and before you know it that one month becomes two or three months.

I would admit that spending several hundred pounds installing solar would make me think twice, but theres cheap kits availible or if buying new negoetiations to be made.