# solar panels and power worries?



## badger (May 9, 2005)

I have been impressed recently by the effectiveness of a roof mounted solar panel, which only keeps the batteries topped up.

2 pals of mine have them and they work great. I am a worry guts, I am always saying to Jen not to use the lights too much or only have the pump running for a few seconds, when we are not on hook up, as "the battery may run down".

The truth is, we only go away for long weekends at the most. We try and get (we prefer) hook ups, and only have to use battery power about 4/5 times a year. We dont wild camp and we dont have TV, Laptops, DVD or and other
luxury to power, only the lighting, and the pump etc.

We have ( i think) an 85 ah battery, dont ask me technical stuff like gel or liquid etc as I couldn't tell you.

Question. should I be concerned about using too much battery power and am I wasting time and money considering a solar panel. (we have a hi top campervan.)


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## johnsandywhite (May 9, 2005)

Hi *badger*. As you are a site user and NOT a Wild-Camper. I would say that Solar power is a complete and utter waste of money for you. However. A small battery top-up Solar panel charger would keep your batteries in good condition all year round. Batteries do go flat just being stood in all weather's. :wink:


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## peter (May 10, 2005)

Hi Badger, I am in the same position as you, my partner thinks I go over the top.

I am considering of buying an extra battery to double up the amp hours for the time being, but I will be purchasing solar panels for next year, as I intend to wild camp a lot more.
If you are considering an extra battery make sure the original is up to strength as it could pull the new one down.

Thinking along those lines I think I had better get two new ones as I don't know how long the older one has been in use, as the previous owner never looked after the motorhome, so I must assume the battery is an olden like me lol.

Pete


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## peedee (May 10, 2005)

I agree with John, unless you are an avid wild camper they are a complete waste of money. I wild camp occasionally, and use sites without electricity and even use the tele sparingly on these occasions. If you are like me the cheaper option is to double up your battery. I have two 85AH batteries and can generally go 4 days without needing a hookup. 

When not using the motorhome it is connected to the mains and I only have to worry about the starter battery going flat but usually it is never stationary long enough for that to be a problem either.

peedee


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## 88742 (May 9, 2005)

Would also agree with what's already been said, your much better off adding a second battery.


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## peejay (May 10, 2005)

Me too, a second battery is the way to go..

pj

ps, or you could really upset a few on here and get a _generator_ :roll:


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## badger (May 9, 2005)

MMMmm I'm concerened that peedee said he can get 4 days on 2x 85 ah batteries. Well i've been on batteries for 4 days with only one and the battery didn't run down.

whats the rating needed for a solar panel just to keep the battery topped up? and would that be the same for 2 batteries?


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## spykal (May 9, 2005)

badger said:


> whats the rating needed for a solar panel just to keep the battery topped up? and would that be the same for 2 batteries?


Hi Badger

That question is a bit like "how long is a piece of string"....It boils down to what you take out you will have to put back in...so If you want to get techy you can try by sitting down and estimating how much 12 volt electricity you are going to use....add up all the times that lights, pumps, Tv etc are on and check the amperage that is used by each ...do a calculation and end up with the total amount you are likely to use in a day......then you can estimate the size of solar panel that you will need assuming that the sun is shining when you need it to shine :roll: .

OR you can do as has already been suggested and get a second battery a solution that for the weekender in a smaller van....like you and me ....is by far the best and most economical way to go. This really only applies if you are able to keep the van on hook up during the time between outings. In my case I make sure that both batteries are fully charged before leaving home but I do not have them permanently linked together. The second battery is used for the TV and computer leaving the main leisure battery for the domestic side. If we flatten the second battery by watching to much TV we then limit our TV to the news while the Tv is connected to the main battery.

We have lasted 5-6 days easily like this without a hookup or driving. After using up the available power in both batteries I have found it needs quite a long time ..maybe 2 - 3 hrs or more ( no detailed checks done yet :wink: ) driving to get them both topped back up.

By the way if you use the batteries in this way you are giving them a hard time and you should expect to replace them quite often, maybe every two years or so, if you wish them to always be able to hold and take a good charge but at around £30 for an 85 amp Leisure battery this is still a good deal cheaper than the hundreds of pounds you will need to spend on Solar panels.

Before any of you out there tell me that your solar panels are the "best thing since sliced bread" ....I do agree they are... but for me and Badger it is a case of "horses for courses" and in this case "Solar Panel" fell at the first fence (expense).

Mike


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## badger (May 9, 2005)

Thanks for that spykal, the probl;em seems to be, that I am not able to hook up when at home. The only charge that the batteries get is on the move, or on hookup on site. Other than that, none at all.


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## peedee (May 10, 2005)

badger said:


> MMMmm I'm concerened that peedee said he can get 4 days on 2x 85 ah batteries. Well i've been on batteries for 4 days with only one and the battery didn't run down.
> 
> whats the rating needed for a solar panel just to keep the battery topped up? and would that be the same for 2 batteries?


I quoted 4 days because that is about the max I stay without recharging. As Mike says it all depends on your usage as to how long you can last. In the summer months it much longer than the winter for obvious reasons plus batteries don't perform quite so well in the winter months.

I have never bothered too much about solar panels, but in your case you might have a look at http://www.solartechnology.co.uk/acatalog/Calc-fit.htm for more info

peedee


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## spykal (May 9, 2005)

Hi Badger

I was worried you were going to reply with that answer :lol:

If you use the van often as an everyday vehicle then fitting the extra battery would still be the first option to try, wired in to the present system....because if you do end up having to get some solar panels you will still need the maximum amount of storage to make them worthwhile having because the sun does have the habit of disappearing just when you need it!.

Thinking about your problem a different way, this idea would depend on how far your home is from where you park .....how about fitting an extra battery with quick release fittings and take it home to charge it up in between trips.....you could do this with the main battery as well if the van is left standing during the week. not only will you set off on a trip with a full charge but the battery life will be longer too.


Mike


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## johnsandywhite (May 9, 2005)

A small battery only Solar charger would still be the best answer. He wouldn't have to lift out and carry the batteries home to re-charge. :roll:


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## badger (May 9, 2005)

would that be a fixed unit or would it have to be set up each time you need it?


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## johnsandywhite (May 9, 2005)

Hi *badger*. Various types are available. Try this Here


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## Bazbro (May 9, 2005)

Badger, how about gas lighting? Very atmospheric (in a Victorian or 1950s caravanning sort of way!)

Truma do "Nova Gas Lights" in their motorcaravan section here:
http://www.trumauk.com/

Then you could save your 'lecky' for the tv (haven't found a Calor gas-powered tv yet!)

We had gas lights in our first Westphalia, back in the '70s and it was quite effective.


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## 93309 (May 1, 2005)

Hi badger 
i agree with what johnsandywhite says if your on sites, save you money

veralin


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## nobbythehobby (May 9, 2005)

Hi,

I'm a solar user and a free camper and agree with pretty much everything that has been said here.

It is unnecessary for anyone who habitually uses sites and hook-up to spend large amounts of cash on a solar system. Even for those who can make use of solar, it is easy to go OTT in specification. I know, I did!

Dependant upon your parking arrangements and access to constant hook-up though, I would suggest that the use of a small solar charger possibly with the use of a battery master to keep your engine battery in top shape is worth considering. Many alarm systems take constant power from the engine battery for example. Having the engine battery in good shape at all times is priceless.

Nobby


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## Boff (May 10, 2005)

Hi Badger and all others,

I disagree with some of the opinions posted here:

As long as you are only week-ending and not using any power-crunching devices like TV etc., a 85 Ah battery is way enough, so I would consider the installation of a second battery a complete waste of money.

Your problem however is that you don't have a hookup at home. Because the alternator charges the battery only up to about 80-85% while driving, unless a special (e.g. Sterling) alternator regulator is installed. *So if you do not have the opportunity to get a hookup for consecutive 24 hours at least about once a month, then you should consider installing a solar panel!* And a good solar regulator.

Otherwise you will slowly kill your battery by regular incomplete charging. And should you install a second battery you will kill them both...

Best Regards,
Gerhard


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## badger (May 9, 2005)

Thanks to everyone for their input on this, I knew you all wouldn't let me down.

Just to reiterate then BOFF. are you saying that if I hook up my van and switch on the internal charging system for at least 24hrs once every month, then a single 85ah battery should suffice?

I attend a site every month, usually from Friday evening to Sunday morning, during which time, I am on hook up.

Would that be OK ?


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## Boff (May 10, 2005)

badger said:


> Just to reiterate then BOFF. are you saying that if I hook up my van and switch on the internal charging system for at least 24hrs once every month, then a single 85ah battery should suffice?


Of course I do not know how much power you consume, but yes, I would say so. I have a single 105 Ah battery in my van, so only slightly bigger than yours. And even in deepest German winter with Truma heating running all day, lights on several hours a day and water pumping for a hot shower each morning this lasts through a wild-camping weekend without hookup with no problems.



badger said:


> I attend a site every month, usually from Friday evening to Sunday morning, during which time, I am on hook up.
> 
> Would that be OK ?


Yes, that is OK. Provided that your internal charger is a good one with an "IU0U" characteristic curve.

Background is: There are two things a battery does not like at all: Being kept at partially charged levels for a long time and "sneaking" discharge. And in practically every van you have some of those tiny little sneaking dischargers like e.g. radio, clock, alarm or the safety valve of a boiler. If you then only rely on the alternator for charging, then you will run into trouble with your battery quite soon. Because the alternator (and it's standard regulator) is designed to top up the engine battery, not the "household" battery.

Best Regards,
Gerhard


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## 88724 (May 9, 2005)

Hi 

If the charger as Plug in systems or Zig on the front, it wont charge fully in under 4 weeks, as chargers thet are pretty useless.

An Alternator wont put much more than 70% in at best without a smart reg.

Installing a second battery, never a good idea batteries need to be matched, ie you would throw the old one and buy two new ones, mismatched batteries will bring each other down and cause premature failure.

Solar little units 30 watts and less may keep the battery charged in storage not much use as a power supply unless you needs are minute.

A decent solar system to provide any usefull power costs money. Means leaving the vehicle in sunshine (which then costs you power to cool!! I s reliant on the weather, ergo unless you build a lot of redundancy in its not going to reliably provide enough power.


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## peedee (May 10, 2005)

GeorgeTelford said:


> Hi
> 
> Installing a second battery, never a good idea batteries need to be matched, ie you would throw the old one and buy two new ones, mismatched batteries will bring each other down and cause premature failure.


Agree they need to be matched, however if you check the SGs of each cell of an existing battery and all is well do not see why you cannot parallel a new identical AH battery with it. The old battery may give up the ghost first but regular checks of 
cell SGs would be essential even with two new matched batteries.

peedee


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## 88724 (May 9, 2005)

Even with the 10 Batteries I have and they are serially one after the other off the production line there will be slight variations.

Variations in age and size and all the other factors means they will charge and discharge differently, the weaker will pull down the stronger.

1 weak cell effects the whole battery, but one weak battery effects he whole bank in the same way.


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## peedee (May 10, 2005)

So you are agreeing with me then George?

peedee


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## badger (May 9, 2005)

There you all go again...........far too technical for a *plonker* like me......You all seem to know your subjects, but as a user....all I need to know is whats the best (for best read easiest) way of ensuring that I keep my battery up to scratch, so that I dont run out of battery power during a long weekend, or have to prematurely replace my leisure battery.


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## peedee (May 10, 2005)

Well Badger, what ever you decide to do, and one of your options seems to be to do nothing but carry on as you are, I would recommend you go out and spend £3 at your local motorist centre and buy a Hydrometer which will enable you to check the Specific Gravity (SGs) of each cell of your battery, unless it is of the sealed variety. They come with instructions and I consider it to be the most important and easiest way of checking the state of your battery.

peedee


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## badger (May 9, 2005)

Thank you for that Peedee, I will do just that and *Thank you everyone *for their input.
It seems that maybe solar panels may be a little OTT for the amount of battery power I use, and may be wasting money on a second battery for the same reason. (although if i find my battery ever needs replacing I will consider a higher rating) 
*I will *find the condition of my battery, *I will *find out how good the charger in the hook up unit is, and if its not that good I may invest in a decent charger and remove the battery periodically for charging.

AM I LEARNING THEN OR WHAT?


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## 88724 (May 9, 2005)

Hi Badger

Would say yau have made a wise choice, you have no paticular power problem to fix. If you have a zig or plug in systems "charger" it would be good to charge the battery properly after every trip. 

Reason if you only ever camp onsite a zig will do enough, any off site camping with Zig and or split charge relay is abusing the battery.

SG is ok to make sure each cell is OK, unless you know what reading it should be when fully charged its not much use at telling you when the battery is fully charged.


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## Boff (May 10, 2005)

Hi George,

just one question I wanted to ask earlier but have forgotten: What does "Zig" mean? 

Best Regards,
Gerhard


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## johnsandywhite (May 9, 2005)

It's the maker's name of a Power Control Unit. :wink:


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## 88724 (May 9, 2005)

Hi Gerhard

Zig make electronic control panels and Chargers/power supplies (13.8v constant)

Zigs webpage


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## 88923 (May 10, 2005)

hi there,

I think I need a battery top up solar panel to stop the starter battery from going flat when the van is stationary for more than 10 days. It's happened three times now  and I could kick myself each time. The flat battery then does something to the immobiliser .....well you know the rest! 

A lot of cussin' n swearin' takes place trying to get the battery out of a Fiat Ducato when the dozy persons that fitted the alarm, fitted the siren next to the battery so that has to be removed before I can get the battery out....... :evil: 

Anyway- any suggestions - apart from not leaving the van for more than 10 days - sometimes I have to.

Banjo 8)


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## 88966 (May 11, 2005)

Hi Banjo,

If your battery is going flat after 10 days there are 2 possible reasons (assuming it is fully charged when left), the battery is knackered or there is a small load. Check both carefully first.

BillD


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## 88923 (May 10, 2005)

Hi BillD,

Still having probs with the battery. I fitted one of those dashboard solar panels (yes, I know it was probably not worth the bother but too late now) but no luck and now the flippin van won't start after a couple of days. It's not flat because it only takes about an hour and a half to recharge.

One of my mates in work reckons it could be the split charge relay that's not functioning correctly. Now I sort of understand what that is but could it really be the problem or should I just go and get a new battery?
Apologies for being a thicko 8O with this technical stuff..........but I *can* cook and wash and clean....... :wink: :lol:

Any ideas? (Like stop being a tight **** and go get a new battery!!!)
Banjo 8)

PS Going to York on Saturday but will be in disguise ...dark glasses etc
8) 8) may see some of you guys up there - I'll be hovering around the battery stands no doubt :lol:


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## badger (May 9, 2005)

Banjo.....I recently had probs like that with my Car......the battery kept discharging when parked overnight.

I charged it and had it checked and was told....its knackered.
Got a new battery and......same thing.........turns out it was the alternater discharging the battery.


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## 88966 (May 11, 2005)

Hi Banjo, 

As you can imagine it is difficult to be too definitive about problems that one cannot actually get ones hands on but again I will try with a couple of points. 

If you wish to try yourself read on - otherwise take it to a vehicle electrician. 

I would suggest you need 2 instruments, a hydrometer and a multi-tester (make sure it will read up to 10 amps). These are not expensive - you will probably get both for a tenner. 

When you think your battery is fully charged, check the SG of all the cells. Don't worry too much at this stage about minor differences but they should ALL be showing fully charged. If not you almost certainly have a duff battery. 

If the above is OK, disconnect one terminal - be careful and don't cause a short on anything !!! 
Put your multi-tester between the battery terminal and the disconnected lead (set to 10 amps scale) and see if any current is flowing. If there is you have any this may be the cause of the problem - although it is possible a very small current may be flowing to an alarm circuit. 

If your battery is good and there is a significant current flowing, take it to a vehicle electrician. 

I hope this helps and good luck. 


Hi Badger,

What was the sequel - did you need a new alternator or were you able to replace some diodes ?


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## badger (May 9, 2005)

Yep.....Had an exchange unit fitted..............now the bloody clutch has gone....

carless of me I know........


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## 88923 (May 10, 2005)

Hi BillD,

When you say 'check the cells' I'm not sure how to do that because it's just all one block - a sealed unit? I've checked that sort of thing on my old Escort (about 20 years ago!) but never had to do it since.

Anyway, a friend is coming over tomorrow to look under the bonnet, kick the tyres about (why DO men do that no matter what bit of the vehicle they're looking at??) and no doubt tell me that the battery is kanckered, I'll print your post off though because if I say do this and that he'll just pat me on the head and say 'no dear, couldnt be that....' but if another block has said it then it might be true! :wink: 

Thanks anyway
Banjo 8)


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## 88966 (May 11, 2005)

Good luck with your friend Banjo,

There is an old saying about fixing things that says it's knowing where to kick things that is important.
It's like farmers at market, they are so used to giving cows, etc a poke with their stick to make sure they are OK they poke everything they look at, tractors, carts, implements, etc.

Let me know how you get on.


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