Solar questions - design, tilt, recharging e-bikes, etc (1 Viewer)

[two]

You don't say what your touring habit will be. If you move on every couple of days, you won't need solar at all.
You haven't mentioned B2B. I'd recommend that, especially for charging e-bike batteries (while on the move).
You don't see many tilting solar panels and I assume that's because they are not worth the faff. Modern panels claim to capture at low angles of incidence (although I don't believe it). I'd consider a portable panel: if you're parked under trees you could move it into the sun and rotate it through the day. Solar's good but your battery bank has a modest capacity. 100Ah of available capacity = only 1.2kWh (twentypence-worth of energy). As said above, 1litre of LPG provides 7kWh of energy (no good for charging e-bikes but the cheapest form of heat) and you should have several litres of the stuff at your disposal.

Get a B2B (capable of charging Lithium in the future). Don't bother with the second system, You e-bike batteries may have greater capacity than that, anyway, so charge them as you travel (mine are 500Wh each).

I wouldn't fret over the unknown. Find out where your shortcomings are and address them once you've found out what they are. You could spend masses of time (and money) over-thinking and solving problems unnecessarily, even if you have plenty of both.

 

[Al n Val]

i’m using a pair of Leoch PLC100ah batteries with 240 watts of solar for most of this summer season.
We used them heavily i’d say when the rain has come, watching tv quite a bit, charging 2 phones, 2 ipads, and all the other bits like recharging 12v fans. Then the last 4 weeks we’ve used our inverter for the kettle, toaster and hairdryer.
Up to now i’ve never seen them less than 83% at night and at 100% by 9.30am the next morning, i’m not sure if this is good or bad but they really seem to be doing very well in my book .

I may well change to Lithium in the future but as these have a 5 year warranty that won’t be until 2026 maybe (hopefully)

Al

 

[The Wino]

We've only got diesel. I can see the attraction of one of the cheapies as a backup if gas is the main heater but they do use a bit of battery on startup.

^{_{Subscribers  do not see these advertisements}}

 

[Tony50]

We had a Solar 100 watt French solar panel fitted in 2007 that raised itself and followed the sun every 20 minutes and I swear that the power it took to follow the sun was almost what it put in the batteries !! can't remember the name of the system.

 

[MitchandJenny]

I looked at your Leoch batteries and £239
each in uk, but only $213 in USA…
Profiteering ??
Mitch

 

[Al n Val]

I looked at your Leoch batteries and £239
each in uk, but only $213 in USA…
Profiteering ??
Mitch

not really, once you take into account, shipping, import duties and handling fees you’ll be paying a lot more for them from the USA

And you have to remember that usually the USA prices are very often advertised without their local vat rate added on which varies from state to state

^{_{Subscribers  do not see these advertisements}}

 

[ChrisL]

P

I looked at your Leoch batteries and £239
each in uk, but only $213 in USA…
Profiteering ??
Mitch

Possibly cheaper to ship from China to America, also the USA is a bigger market so bigger discounts to wholesalers for buying larger quantities. If you are intending to buy more than one battery it's worth ringing alpha batteries and asking for a discount, the advertised price for the batteries i bought was already discounted, but they still knocked a bit off for buying three.

 

[MitchandJenny]

Ta ChrisL
But will stick with what I have.
Mitch

 

[Glas Robin]

Thanks everyone for all the replies and advice. Most helpful.

^{_{Subscribers  do not see these advertisements}}

 

[wfdTamar]

But they are AGM.

I should have said forget the conventional AGM. The lead carbon solves the issues with them.

 

[Glas Robin]

One quick design question.

2 x 150w panels in parallel - peak voltage 18v, peak current 9amps per panel..

What size inline fuse should I install between the panels and the controller? 20amp? or 15amp?

Same again between the controller and the battery?

 

[wfdTamar]

It's been a while since I installed mine so I'm a bit rusty on things like fuse sizes, but this page gives a good guide. The Votronic has a fuse in it, so you may not need a fuse between controller and battery (but again, I'm rusty so I may not be correct).

A & N Caravan Services : Solar Power

Solar Power for Motorhomes and Caravans - Do's and Don'ts, Hint and Tips. We have seen many poor Solar Installations. This guide will help you work out if your prospective Solar Panel installer knows your Motorhome.

www.aandncaravanservices.co.uk

BTW, I used a Votronic in my Hymer and once I actually got a working one, it works fine, but Epever do a similar one (that can also charge the starter battery) and their ancillary things cost a lot less than Votronic (thinking of things like the display), though the Votronic display looks nicer. Bimble stock it.

DuoRacer Series(10~30A) Dual Battery MPPT Charge Controller

MPPT charge controller DuoRacer charges the main battery (BATT1) for living and supports charging to start the battery2 at the same time.

www.epsolarpv.com

I set up mine to run the fridge via AES when there was excess solar and it hardly ever did it (200 watts of panels in France in summer). The fridge (a standard 100 odd litre one) uses about 10 amps on 12 volt. Could be the fridge had a problem as it did die completely after a few months.

I have the Votronic display which among other things shows battery voltage and I was using that as a way to assess the state of charge of the battery (how empty it was), but apparently that's not a very accurate method. You're better to use a display that also uses a 'shunt' like the one on the AandN page above.

^{_{Subscribers  do not see these advertisements}}

 

[Glas Robin]

BTW, I used a Votronic in my Hymer and once I actually got a working one, it works fine, but Epever do a similar one (that can also charge the starter battery) and their ancillary things cost a lot less than Votronic (thinking of things like the display), though the Votronic display looks nicer. Bimble stock it.

DuoRacer Series(10~30A) Dual Battery MPPT Charge Controller

MPPT charge controller DuoRacer charges the main battery (BATT1) for living and supports charging to start the battery2 at the same time.

www.epsolarpv.com

Thanks. Funnily enough I bought that controller yesterday as I couldn’t find the Votronic in the UK for love nor money.

 

[wfdTamar]

Not sure what Robin is referring to?

I think the Epever will be fine. I tried to get support from Votronic in Germany when I first got mine and it didn't work. They didn't even answer for months. I had to buy another one just to prove to the NZ seller the one he sent was faulty.

 

[Raul]

One quick design question.

2 x 150w panels in parallel - peak voltage 18v, peak current 9amps per panel..

What size inline fuse should I install between the panels and the controller? 20amp? or 15amp?

Same again between the controller and the battery?

For solar, if you fuse it has to be gPV ultra fast blow. Anything else will be useless. They come as 10x38mm cartridge in a holder. You can fuse 20a in parallel fo both, 9a or 10a individually. From the controller a 25a dc (midi fuse) is needed or even 30a on a min 6mm2 conductor. Depending on length you may need to step up to 10mm2.
Ps, the 300w solar is very little for off grid up north. You can do better.

^{_{Subscribers  do not see these advertisements}}

 

[the1andonly]

Although the general thought is not to use a separate system for your bikes i would consider it but add a Lithium for the main system (to add to when rich and famous) For Northern use, 450W solar a minimum. The use of a dual system may be appropriate in sub zero C conditions. Space seems to be your limmitation to size of panels (Domestic 50V + efficient)
would a roof rack mounting system reduce your space limitation. sorry to add a few new thought. Ps Raul knows what he's talking about

From an old thread on tilting
Angle of Panel
For a very simple system of just tilting 3 positions i used the data available on the net and 2 apps to create this table

latitude Summer Spring Autum Winter
Angle of Panel
50.8 Portsmouth 21.7 46.7 68.5
52.2 Northampton 23.5 48.7 70.5
55.0 Newcastle 26.3 51.6 73
57.1 Aberdeen 28.1 53.6 74.7
58.0 Stornaway 29.1 54.5 75.6
43.0 south of france 15.3 39.8 62.3
38.7 Lisbon 10 34 57
these are from averaged values across a season
what can be seen: if you set at Northampton you will only ever be 5 degrees from optimum anywhare in Mainland GB. 5 manual settings is the most you'll need.
The vertical tilt is the easiest of the orientations to achieve.
Rotationaly a lazy suesan is a simple approach but i couldn't suss a simple mechanical control.
When i started looking at the shaowing effect of a moving panel on adjacent panel area i jacked in the idea and bought a 330W panel 1.6 x1m . best use of space.

Ap used = solar tilt

 

[wfdTamar]

I just got an Epever Triron MPPT controller and it weighs a ton (and is huge) - about 3 times the weight of the Votronic I have in my Hymer (same capacity).

 

[Glas Robin]

I just got an Epever Triron MPPT controller and it weighs a ton (and is huge) - about 3 times the weight of the Votronic I have in my Hymer (same capacity).

Yep - Epever Duoracer arrived yesterday too. It's quite some brick...

^{_{Subscribers  do not see these advertisements}}

 

[suavecarve]

Have you had a think about an underslung tank and getting selling the tank you have at present and you could get the underslung tank for near to the price you would pay for the extra tank and the sale of the current one ? This would also give you space to store loads of cassettes for your wee !

I saw a thread of a newbie from Sweden the other day and one from Finland and we have Northern Boy in Estonia whose brains might be worth tapping into re how they sort out solar over their winter

Best of luck

 

[Northern Boy]

Have you had a think about an underslung tank and getting selling the tank you have at present and you could get the underslung tank for near to the price you would pay for the extra tank and the sale of the current one ? This would also give you space to store loads of cassettes for your wee !

I saw a thread of a newbie from Sweden the other day and one from Finland and we have Northern Boy in Estonia whose brains might be worth tapping into re how they sort out solar over their winter

Best of luck

Happy to talk about solar up here in the 60th degree, or lack of it during the winter

I must say solar farms are popping up like mushrooms in the rain all over Estonia (must be the money from Brussels, oh dear you don't get that any more do you). Oh you should see all our new cycle paths too And the wonderful covid passport with no nose testing

Sorry about that just having a morning giggle, I do miss the UK, I just want to relive one season all year round. The Spring, Summer, Autumn, Winter stuff is getting a bit repetitive here

Where was I? oh yes, In the summer solar is great when we generate heaps of leckie. But in the winter when we need it for heating the output is rather poor. Sometimes in mid December the sun does not even climb above the trees in our garden!

 

[eddie]

Happy to talk about solar up here in the 60th degree, or lack of it during the winter

I must say solar farms are popping up like mushrooms in the rain all over Estonia (must be the money from Brussels, oh dear you don't get that any more do you). Oh you should see all our new cycle paths too And the wonderful covid passport with no nose testing

We not paying for that anymore or other peoples cycle paths and we have all been vaccinated

^{_{Subscribers  do not see these advertisements}}

 

[dash300]

We not paying for that anymore or other peoples cycle paths and we have all been vaccinated

Precisely; as a net EU contributer! As the UK is no longer subsidising Estonia I can't quite see what he is laughing at.

 

[Glas Robin]

An update on the solar tilt project.

I've got a working prototype of a tilt mechanism using a 250mm linear actuator and some aluminium box frame. I'm just adjusting the attachments/trig calcs. It works well and swiftly through a flat to 90 degree upright range.

It needs a lock to ensure all stays where it should when I'm driving as there is some necessary play in the actuator attachments. I don't fancy popping out of the roof vent to manually lock it. I'm thinking of a 12v electromagnetic door lock that is powered from an ignition feed, on the basis that it's only needed when moving. The cheap one I'm looking at has a 60kg holding force and draws 0.1 amp when powered. The panel is about 15kg in weight.

I'll wire to a switch and lamp on the dash, next to the switch for the tilt just so everything is obvious.

What think you all of this solution?

 

[Raul]

How about something that auto latches by gravity on the way down, and electromagnetic actuated to unlock before lifting? Similar to a electric door entry ?

^{_{Subscribers  do not see these advertisements}}

 

[Richard n Ann]

Seems like a lot of faffing and extra weight to me. I just lift ours up myself, oh and give it a clean while I'm up there

 

[The Wino]

An update on the solar tilt project.

I've got a working prototype of a tilt mechanism using a 250mm linear actuator and some aluminium box frame. I'm just adjusting the attachments/trig calcs. It works well and swiftly through a flat to 90 degree upright range.

It needs a lock to ensure all stays where it should when I'm driving as there is some necessary play in the actuator attachments. I don't fancy popping out of the roof vent to manually lock it. I'm thinking of a 12v electromagnetic door lock that is powered from an ignition feed, on the basis that it's only needed when moving. The cheap one I'm looking at has a 60kg holding force and draws 0.1 amp when powered. The panel is about 15kg in weight.

I'll wire to a switch and lamp on the dash, next to the switch for the tilt just so everything is obvious.

What think you all of this solution?

I think a catch that needs 12 v to release it would be a good idea. If theres a gale while you're storing the MH the wind strength could easily be as high as when you're driving. Are you thinking of a rotating turntable to mount it on it will otherwise limit the way you park.
If you do have a locking electromagnetic catch when driving it's the size of the panel that will determine the strength of catch required not the weight you could fit a fairing in front to reduce any lift.