help please- leisure batteries + solar panel

[davidmclaren]

My motorhome battery site location only enables me to have a 85ah leisure battery in place. As I only go to sites to charge up I have decided to bite the bullet and get power supply consisting of solar panel + 2 batteries ( 95AH - 110AH whatever I can fit. . My current battery location is at the front of the van - but the only place I can fit another ( or 2 ) is under rear seating storage area . My questions are :

 

1. Who to source reasonably priced/ decent quality 120 /150 w solar panels ( eg Sunstore/PhotonicUniverse or any decent Ebay suppliers)

 

2. Is it possible to keep my existing 85ah battery location and add 2x110ah in the rear storage area ORis this impracticable?

 

3. If the 3 battery suggestion (as above) is not an option can I add one 110ah battery to the rear storage area or is better to have both batteries at 85ah?

 

4. Any recommendations re Numax/Powerline/Explorer OR do you recommend going for the more expensive Varta/ Banner range?

 

5. I am sure some of the battery ranges are one and the same. eg Lucas the same as Numax? Or am I wrong in this assumption?

 

Any constructive help with the above would be much appreciated. Thanks

[Guest Joe90]

My advice would be to first look at your likely 12 volt usage. I have all led lighting, 12 volt led TV, Truma blow air heating, and an inverter for charging phones etc. We have a single 110 panel , and a single 95 amp battery, this setup has proved more than adequate for us,, almost always being off grid as we rarely use sites with hookups. For those that want two batteries, the perceived wisdom is two brand new ones of the same make and capacity, though as I say a single one that is a Lucas branded one,combined with 12 volt efficiency measures has been more than sufficient for us.

[colin]

We have similar set up to Joe, If going down the solar route you can fit a panel first, then if you need extra batteries add them later. Fitting different size batteries in different locations will not get the best out of them.

[davidmclaren]

Hi - thanks for the reply. My 12v usage is the water pump, fridge ( only whilst on the move - it runs on gas whilst parked) , Truma heating, lighting, phone and the laptop .The lighting is non LED at present altho I am looking to change over to LED very soon.

[spartan3956]

I fitted a 120 watt solar panel and a 10 amp regulator , all connected to single battery

With tv heating and lights (led) evening usage by midday the battery is fully charged again.

 

It all depends on usage if you watch tv all day you probably need more batteries

In my last camper same solar set up, with normal Halogen and strip lights i had two 110 amp/hr batteries connected together

All connected to a 2000 watt inverter that powered the kettle when in the Tunnel as you cant use gas and a cuppa was just the job

It also powered an upright vacuum cleaner when on site. yes a bit OTT but give you an idea what you need.

 

As others have said the same size and matching batteries should be used as the larger one will never get fully charged.

 

[Brambles]

From what you have mentioned about your use, you are not a big power user and one battery should be fine for 2 or 3 nights depending how much you charge your laptop.. The Truma heater fan will be the biggest user in winter and to get away with a few nights without recharging then a second battery would help a lot and be plenty.

 

You can have a 2nd battery larger than the 1st and it WILL get charged up as well. Think of it as a large water tank and slightly smaller water tank connected together with a pipe at the bottom, both will fill up to full and both will empty together as long as the load is not massive which it is not. The recommendation is batteries are similar age, type and size. It is best to keep to within one size difference for safety reasons when they get old and one fails, and generally within a years age of each other. Technically you could fit a (ten) 10AH and a 180AH and both would cycle together and have the same life if the the same type. The problem comes when say the 10AH fails with a shorted cell, you can get 180AH discharging through the poor little thing and it does not cook but fries.

Same type means Flooded , AGM or Gel but I like to take this one step further with Flooded in they are both identical sub types. e.g. I would not mix a Banner with a Varta Leisure. That is because they have dissimilar voltage characteristics the Banner being predominantly antimony/calcium based and the varta Silver/Calcium based. So the easy answer is same make.

 

[davidmclaren]

Brambles - 2014-09-15 8:44 PM

 

From what you have mentioned about your use, you are not a big power user and one battery should be fine for 2 or 3 nights depending how much you charge your laptop.. The Truma heater fan will be the biggest user in winter and to get away with a few nights without recharging then a second battery would help a lot and be plenty.

 

You can have a 2nd battery larger than the 1st and it WILL get charged up as well. Think of it as a large water tank and slightly smaller water tank connected together with a pipe at the bottom, both will fill up to full and both will empty together as long as the load is not massive which it is not. The recommendation is batteries are similar age, type and size. It is best to keep to within one size difference for safety reasons when they get old and one fails, and generally within a years age of each other. Technically you could fit a (ten) 10AH and a 180AH and both would cycle together and have the same life if the the same type. The problem comes when say the 10AH fails with a shorted cell, you can get 180AH discharging through the poor little thing and it does not cook but fries.

Same type means Flooded , AGM or Gel but I like to take this one step further with Flooded in they are both identical sub types. e.g. I would not mix a Banner with a Varta Leisure. That is because they have dissimilar voltage characteristics the Banner being predominantly antimony/calcium based and the varta Silver/Calcium based. So the easy answer is same make.

 

Hello Brambles and thanks for your very helpful reply. My usage is not high but I much prefer to stay on the movevand only go on a site for sole purpose of charging up. I had provisionally decided to go with 2 x Numax 85ah + a 150w panel . The reasoning behind the 85ah is simply because that is the max I can fit into the current battery site location. I would be adding the 2nd battery under the rear seating storage area.Of course I have the option of resiting 2 x110ah batteries under the rear seating storage area and makiing the existing battery location redundant. What do you think ?

 

As for the panel - I decided to go for the biggest I could fit on the roof space available ( approx 1600mm x 700mm). I have sourced three and would welcome thoughts and opinions as to choice.

 

1.http://www.ebay.co.uk/itm/150W-solar-panel-for-boat-caravan-motorhome-camper-12v-150-watt-with-brackets-/301138031725?pt=UK_Gadgets&hash=item461d39b46d

 

2. http://www.ebay.co.uk/itm/Biard-150W-Watt-Black-Framed-12V-Monocrystalline-Solar-Panel-Money-Energy-Saving-/181375333362?pt=UK_Gadgets&hash=item2a3acff3f2

 

3.http://www.ebay.co.uk/itm/150W-solar-panel-with-5m-cable-for-motorhome-caravan-boat-marine-150-watt-/140896867313?pt=UK_Gadgets&hash=item20ce1b93f1

 

Finally re equipment - any thoughts on what regulator/controller - I had the Sunsaver Duo in mind.

 

You might think that I am overdoing it but as I say I want to stay on the road for as long as possible without going onto a site.

 

I am also the type that listens to constructive opinions and advice from those more experienced and knowledgeable than myself. So please fire away and give me your thoughts - they will be appreciated I can assure you.

 

 

 

[Brambles]

First of all do remember when driving your batteries are being charged. However if you are only driving for 30 mins or so then its not a lot.

 

If you are touring and driving a lot of hours you will replace a lot of the power used. The advantage of two batteries is you are in effect charging up twice as much power which you can then use.

 

Second. Numax. Cheap quality budget type leisure batteries. Fine for what I call coffee stops. You can do better. Many will find excellent because they have a solar panel which masks any low capacity or have hook up a lot, or just do not use very much power. Also number of nights away per year plays an important part.

 

I would go for better quality batteries if you are going for solar panels and actually many find a 80 watt solar panel adequate. Try it with 80Watt 1st and decent batteries. If 80 is not enough you can always add another but I think you will find 80watts is plenty. ... but I am not a solar panel user so see what others say as well. However in theory I have heard a lot recommend your panels in watts should match your batteries in Ah's. This makes a lot of sense if you consider in some weather you might only average 6 hours sun a day. 80Ah battery 80W panel. That is 6.7amps for 6 hours = 40Ah ...Half your total battery capacity which is your recommended usuage. But this is only relevant if you are actually using 40Ah a day and I doubt you are. So I prefer to suggest you match the panel in watts to the actual Ah’s you indeed use per day. A second battery then gives you the reserve for when you need it and reliability of extending your life of the batteries as rather than discharging say 30% every night you are only discharging 15% typically.

certainly at 15% discharge each battery Numax will give you good service.

 

Confused? Yes?. I am not surprised.

 

Better Batteries. You could go fror Banner Leisure batteries. They are much better for deep cycling and long life. However cost a lot more. Now whilst they will give a long cycle life they will need maintaining with occasional water topping up. This is not ideal if fitted under seats and access to topping up is an issue.

 

So in the middle we have Varta flooded leisure. Now it is in the same class as Numax in the respect it is a Dual purpose starter and cyclic battery, BUT it is far superior to a run of the mill dual purpose like the Numax. It is a sealed battery, but has extremely low water consumption and extremely low self discharge, but if you have solar panels self discharge is not quite so important.

 

Now if you feel Varta Leisure is still a bit pricey, then compare with Varta Silver Dynamic starter batteries. They work out a lot cheaper. Some say they are the same battery, I don't know if they are or not but have to assume they are a slightly different specification as weight is very slightly less. However they are an excellent battery and can be cycled.

Now to put this in prospective and is for comparison purposes only as you may or may not get this number of cycles or may get more.

A budget leisure will give you say 100 cycles ( a cheap starter battery for reference will give you 50). Cannot be topped up with water.

 

The Varta silver dynamic ( or Bosch S5) will give you 150 to 200 cycles. (probably nearer 200)

The Varta Leisure will give you 200 cycles. Note the Vartas are supposedly sealed but I would not be surprised if you can force the top cap cover off and top up. The last one I had ( a 40Ah starter in same style of case I managed to remove the top and top it up but there is no guarantee you can. Case designs change all the time. I have not looked closely in anger at a Varta Leisure to see if cover can be removed.

 

The Banner will return about 400 life cycles. Designed with removable caps so you can top it up.

 

All will have central venting ports and should be vented through a tube to outside world. The Vartas have such low gassing levels you almost have no need to vent but you still should for safety in event of a fault.

 

I am not really trying to advise which battery but just give some information and guidelines.

I suppose advice should be. Light user Numax/budget

Intermediate user Varta

heavy user Banner.

 

Hard up almost broke Motorhome owner, broke because he is a Motorhome owner of course..has to be varta Silver starter.

Pots of money no object.. Varta AGM leisure or again Banner.

Pots of Money and abuses his batteries Varta AGM or Exide Gel. Gel for the ultimate abuse.

 

I'm waffling on now. better shut up and post.

 

[Brambles]

Solar panels. Looked at your choices. Not keen on the black surround. It is more for asthetic looks and black gets very hot in the sun so I would go for white surround. Probably does not make a lot of difference but I would think it adds a few degrees of heat and panels do not like to get too hot.

 

I would go for supplier who has the best quality control. Most panels are bit of a commodity item abd cells are graded. Bosch is a brand I have always very highly respected although mainly automotive based. Bosch market an awful lot of differemt products which they just rebrand, dont all big companies now, but Bosch do have very high specs and standards along with quality control over their suppliers so unless paying a heavy premium I would have though Bosch is well worth looking at closely.

Bosch never put their name on low quality products, but that does not mean you cannot buy the same product elswhere cheaper. Take their S5 starter batteries, they will be cheaper with the Varta badge.

I have a Bosch coffee grinder and it is the opposite, it is more expensive under another suppliers badge.

 

If you look at the iage of the panels, the 2nd one?? shows two conductors linking the cells, whereas teh Bosch shows three whochis better. The short circuit current of the Bosch panel is higher which may r many not be related to the extra wire but the extra conductor shows they have not cut every corner to reduce costs. For Motorhome use you probbaly want the panel with the best efficiency in low light levels rather than best efficiency in bright direct sun light. It would also be useful to try and gets the specifications for the aging of the cells and fall off of efficiency over time. Many cheap panels are cheap becaue they are not top grade silicon wafers and they age quickly and efficiency falls. Not much use for commercial use to last 25 years, so panels specified for comerciai use on properties should be specified with longest life. Thats as much as I know about panels. At the end of the day I am no expert on panels.

[davidmclaren]

Thanks Brambles- very useful info indeed. OK - how about compromise ? For example a quality Banner 110 ah battery with a 110ah Numax ? Or is this ill advised ? Interestingly I contacted Manbat and spoke to one of their technical staff. With regard to the Varta and Numax brands he said they were completely different batteries and where the Varta scored much higher was in the cold cranking performance. However this is not relevant to me however. Perhaps the most interesting comment he made was that the Varta 90ah leisure battery was a deep cycle + starter battery hybrid - and to qote " to be frank I just do not see how such dual purpose quality is possibel !!"

[Brambles]

davidmclaren - 2014-09-16 11:49 AM

 

Thanks Brambles- very useful info indeed. OK - how about compromise ? For example a quality Banner 110 ah battery with a 110ah Numax ? Or is this ill advised ? Interestingly I contacted Manbat and spoke to one of their technical staff. With regard to the Varta and Numax brands he said they were completely different batteries and where the Varta scored much higher was in the cold cranking performance. However this is not relevant to me however. Perhaps the most interesting comment he made was that the Varta 90ah leisure battery was a deep cycle + starter battery hybrid - and to qote " to be frank I just do not see how such dual purpose quality is possibel !!"

 

If you mean pairing up a Banner with a Numax then no not advisable. It will work but they are not matched in voltage charging characteristics. Guessing (using my memory) figures so may be wrong, but when the batteries paired reach 14.1volts the Banner is almost fully charged and normally will take very little time to reach say 14.4v when the charger folds back to a lower voltage. However with the Numax paired with it the Numax will still be absorbing charge up to say 14.3 volts so it slows down the rise to 14.4 volts. This results in too much charge going into the Banner and it gasses for too long. It will cope with it but will wear it out quicker so to speak. It is a difficult one to explain. Basically the Banner is fully charged before the Numax as it charges faster and at slightly lower voltage.

Varta/Numax starter batteries. They are not completely different. They are just different.

The varta starters have much better cycle capability and charge acceptance. This is achieved by the design of the plate grids which varta have patents on. It is also achieved by the lead alloys used and additional metals such as silver and tin. Again Varta have a lot of patents and knowledge/experience in making excellent quality batteries. The varta will have faster recharge, more reserve power and better start performance as well as cyclic capability.

Now dual purpose explanation. Traditionally a starter battery was for starting. It needed high reserves of being able to supply a high current for a short period of time. It might only discharge 3% of the capacity to start the engine but needed lots of reserve capacity for this days when the engine does not start, or head lights have been left on overmight. The have lots of thin plates in effect to achieve high current delivery.

Then you would get batteries which are deep cycle, they are for back up power supplies, powering lawnmowers etc, floor washing machines and indeed caravans/Motorhomes. These are not designed to supply large currents so are made with less plates which are much thicker and more robust. The really good ones are called traction batteries and for the lighter applications semi-traction was made.

Varta used to supply excellent leisure batteries which were semi traction. Ideal for us Motorhomers.

They had applications from Floor cleaners, Go Karts, Electric fences and so on. However with the advent of caravans having motormovers and many more leisure users fitting high power inverters so they can use microwaves these Semi traction Batteries would have a reduced life. They were not ideal anymore for some users, perfect for general use if no extremely high loads and were good value overall. Meanwhile Engine starter batteries needed much better cyclic ability bit retain reserve starting current and AGM batteries fitted the bill. However with slight modification ( heavier and less plates) were a far superior semi traction battery but cost a lot more. However this is not an issue as lasted a lot longer in commercial applications. But for consumers they are expensive as we don’t look at life cycle costs and risk murdering a battery before getting max life out of it anyway.

Sorry I am rambling on away from point I was making. Varta no longer provide the original semi traction deep cycle battery and has been replaced with a much more expensive AGM leisure battery to meet the same life cycle specs.

To meet the needs of the more price conscious leisure user and those with high current demands for either yacht engine starting or caravan movers, microwaves, hairdryers etc they have the flooded leisure battery to replace the original leisure batteries which basically is a dual purpose. Many battery suppliers think it is the same as the original ‘hobby’ range which it definitely not but does share a lot of the same characteristics such as low self discharge, lower water consumption, fast recharge capabilities etc but cycle life is half of what the old ones were.

When Varta dropped their semi traction Banner jumped straight in there to market and increase availability of their Leisure range. It’s a semi traction..Hurrah!... is very good quality but as two failing in my mind, it does not share the low self discharge and low water consumption of the original Varta. However it is also less likely to be damaged by heavy loads so wins on that front.

Banner – probably best for life – but requires topping up.

Varta = Probably best quality but slightly less life but more if Banner is not maintained.

Numax – respectable battery for the price concscious or light user/occasional use. Lower cycle life

Generally do not mix and match these batteries, they all have different charging/discharging characteristics.

You know what, I have forgotten what I was going to say in my reply which was intended to be short…I keep getting interrupted....Oh well.

 

[davidmclaren]

Excellent once again Brambles.