Mobile PV setup design?

[T i m]

Don't worry, 'some people' are very sad and can never consider there might be a 'bigger picture'. ;-(

It probably is ... but how about, replacing the panel connectors with something from the Anderson connector range (polarised, self cleaning, non-locking) and bring them into the controller on a bundle of 5 wires, terminating as one (pair). That way you can mix-n-match panel combinations easily and if someone moves a panel away or trips over the cable, no harm would be done.

The layout of the batteries may come down to what you can handle physically. I have 3 x 34Ah semi traction batteries that I intend to use in parallel with an electric outboard (chosen as being the heaviest the Mrs could take off me individually and lower into a boat) and then to sit in a custom wooden tray / box that is fitted around the shape of the hull.

Again, if the battery combinations were on Anderson connectors, it would make it more flexible.

A small batch of 'Smart' (12V would be the cheapest) chargers to either leave on or move between the battery pairs in series would both safely keep them charged and prep them for use when it's an overcast day.

Keep the high current cable runs (controller <> batteries) as short and as heavy conductor as possible. A fuse on / as the battery pair interlink might be a good idea (in case one battery goes short and the other try to charge it).

Even if sealed batteries, keep them well ventilated.

Have fun. ;-)

Cheers, T i m

[T i m]

<snip>

I see the controller is also an inverter / charger so you can skip the bit above. ;-)

Cheers, T i m

[Bill Wright]

24V chargers are a similar price to the 12V equivalent, if you remember that you have to halve the amperage of the 24V one in order to compare capability. Take a look at Numax intelligent chargers.

For a combination of flexibility and minimal voltage drop I tend to use two parallel 84 strand cables. Voltage drop on this sort of installation can be quite an issue.

A fuse on / as the battery pair

Yes. Fuse every battery. I have some battery connectors with integral fuse holders. Can't remember the source unfortunately.

Quick release connectors might be worth considering.

Don't forget to use a good chunky earth strap if you're connecting to a chassis.

Bill

[Brian Gaff]

I wonder what happened to the one that disrupted Derby Day at Epson the other day? Brian

[Martin Brown]

+1

Every time I have tried to do a fixed solar PV based setup a simple pair of SLA batteries of the right capacity charged off the mains has won hands down. Work out how much energy in Ah they need and work from that.

A demo solar PV system on the 100W scale might be OK if you must virtue signal but the kit you have got is basically a nightmare to transport, setup and maintain. Make sure all the battery terminals are fully insulated too or you could have a very nasty accident with a short.

What do beekeepers do with all this portable power - Arc welding demos?

[Martin Brown]

Which would almost certainly be better served by selling the solar panels to some eco nuts and buying the right size of battery for the duty to charge from the mains at home. I have been round this loop more than once and unless the usage is light the solar panel(s) to power it will be so expensive that payback essentially never occurs.

Installed in a remote location you also have to worry about theft.

Incidentally in a fixed but steerable permanent installation you can almost double the peak solar output with a couple of mirrors either side of the panel \_/. It plays havoc with the wind loading but boosts the output at the expense of getting the panel somewhat hotter.

SLightly more sophisticated curved mirrors can concentrate the sunlight to about 10x which is about the limit before the silicon gets too hot and performance really falls off.

OK. So at least you haven't paid good money for them without having any idea of what the system is intended to do or how to make it. It is fairly important to know how much load the thing is expected to drive.

My suggestion would be to split the system into two or more chunks.

A single panel and one battery to take to shows if you must and the rest fixed wherever your clubhouse is. Since you have the panels I suppose you may as well use them and I presume beekeepers do mostly meet in the summer so you should get reasonable Ah yield off the panels.

You would probably be better off asking in sci.electronic.design although don't expect an easy ride there either. It is mostly full of fat ugly Americans for a dead planet who deny AGW science entirely.

PV only really works in the UK if you qualify for a suitable FIT.

[T i m]

<snip>

Go on, give it a try, you never know, *someone* might like you (even as a sort of pet)?

But then the output comes out of your ar$e? I think you need fixing. ;-(

Cheers, T i m

[T i m]

I think they normally contact the local 'bee man' who come and tempt the swarm away.

I was quite surprised that although we were disturbing their homes, how little they reacted? That's not to say we would have felt the same, had we not got the bee suits on of course but there are people why wear a beard or suit of bees and seem to get away with it?

Some don't of course. ;-(

Cheers, T i m

[T i m]

Two things:

(I since noted) The controller the OP referenced is a combined charger / charge controller / inverter.

I find it 'safer / better / easier' to charge each battery (in series) individually, especially as they age or aren't well matched in the first place (especially if the charger capacity is quite good).

Whilst they might be 'good', they aren't likely to be much better than say 6 x Aldi smart charger for the task of charging / maintaining the batteries between events, especially if they aren't part of the 'gifted' deal.

I will often try to use as big a conductor as I can get in the biggest lug that fits the battery terminals.

Agreed.

Where 'a battery' in this case = 2 x 12V in series? eg, if you used a fuse to join a pair together, the fuse would be in that 'battery'.

There is a trade off between the likelihood of a fuse saving the day re it not because a spanner ends up directly across the terminals (where a fuse wouldn't help). I agree with the comment elsewhere of having the terminals covered / protected.

I try to put the fuse as near as I can to the +Ve battery terminal, even to the point where any live cable (to the fuse) couldn't reach a

-Ve terminal.

I previously mentioned the Anderson range.

Agreed.

Cheers, T i m

[T i m]

<snip>

Depending on the 'goals' ...

The entire system was free to the OP / Bee club so the payback would be instant. ;-)

Except it will be 'manned' and bulky to theft risk is very low (I read it as to only be used at 'out' shows)?

Whilst that could be a good tip for a permanent installation, or one where you really do need to optimise the installation, I don't think it would be 'worth it' for this scenario (too much complication, not a std install, not the point).

See above. ;-)

Quite.

Of course. Anything up to 3kw. ;-)

Only if the potential load is 12V and within a reasonable spec. I think the idea would be to make use of the 240V when 'out'.

Not sure that's a valid scenario.

Quite. ;-)

Or you would like power in a remote location to use or as part of a concept demonstration (to support your cause).

There are *many* people living entirely off grid and using PV so it can be done.

We often use PV when camping for charging torch / GPS / phone batteries and it generally works pretty well. However, that may mean optimising the system to best suit those needs (low power torches etc).

I currently have a system under test, providing remote power for an electric fence. I *could* run mains power to the location but I cba.

So, a 12V 6W panel mounted vertically on the West facing side of a shed (because that's where everything is), driving an LCD display MPPT controller to an old (degraded) 30Ah GEL standby battery and then the electric fence unit.

We currently use two 22Ah gel batteries (one in use, one on charge) and swap weekly (ish).

The exciter draws around 60mA and it typically on from dusk to dawn (longer if no one is around to turn it off).

The test is to see how much longer we can extend the need to swap batteries with the minimum effort and risk to the panel (even from the weather etc).

The MPPT controller has an integrated dusk to dawn output switch so that would help conserve battery power.

If the system isn't self sufficient, I can either fit another panel at the East end of the shed or mount one optimally out in the garden.

Being around the longest day of the year, a test around this time (I have a voltage logger on it set for 7 days) should give me the 'best case' (for that setup).

Even if we don't end up keeping it as a solution, it's an interesting thing to play with. ;-)

Cheers, T i m

[John Rumm]

I think part of the difficulty is knowing exactly which bit of it seek assistance on?

I am guessing this is mostly a question of packaging - i.e. how to box up the various bits into manageable sized units, and then a way of connecting them up in a fool proof way after?

[John Rumm]

Fix the solar stands to the battery boxes - that should slow down anyone pinching the panels!

[T i m]

I think it's general guidance and more specific on connectors and conductors etc?

I think the OP had an idea about that and it will be (to a fair degree) a function of how easy any of it will be to move / carry / load / unload etc.

I designed and built a wooden bench that could be flatpacked AND carried in daughters Corsa AND that could store AND support a wood turning lathe. They drove it from London to Scotland and assembled it in a few minutes when they got there, then put the lathe in it. ;-)

As I found to my cost / surprise, some of the different colours of the same model in the Anderson range aren't inter-connectable and that can be used to good effect when making up connectivity solutions for the panels and batteries etc.

Cheers, T i m

[T i m]

<snip>

Aww, bless. I can feel the pain and frustration in your voice. It can't feel nice to be in your position, desperate to hang on my every word but have nothing (of any worth) to come back with or of actual interest to me (sorry, I hope that doesn't hurt you too much))? ;-(

Surely? I'm pretty sure you wouldn't be able to judge to that level on ... pretty well anything! Reason, you would have to have some sort of clue what you were talking about and that's *obviously* not the case (as you have kindly demonstrated ... *again*). ;-(

What the F are you drooling on about now? Are you still hurting? ;-(

Aww, of course you do ... so much for me being 'self important'?

No, best you unsubscribe from being one of my followers ... it's pretty obvious you clicked like by mistake. Maybe you though I was your programmer or carer?

Anyway, good luck with your future ... try to make the most of it, if you can.

Oh, you seem to have gone quiet on the old nymshift accusation? I think you should drink something with that humble pie, might help you swallow it easier?

Cheers, T i m

[Bill Wright]

If you do two at once presumably you disconnect them...

Bill

[Terry Casey]

Not long after I started working in the City, a colleague encountered the housekeeper (aka caretaker) of our building in a somewhat distressed state because a swarm of bees had taken up residence outside her kitchen window!

He recalled that one of his lecturers at college in north London was a beekeeper and phoned the college. Yes, he was still there and my colleague was able to speask to him.

At 5 o'clock he turned up in his car with all his kit and removed the swarm!

[Nick de Smith]

Swarm management is something that a lot of experienced beekeeprs do as a public service, partly as swarms (and there are different types of swarms) almost always come from managed hives as there are very very few feral colonies of honey bees left in the UK. So we feel that it's our duty to collect and manage them.

Generally, it's not tricky once you get the hang of it - swarms are normally pretty docile and easy to handle. If the cluster is accessible and you can get the queen, it's not difficult.

Cheers!

[T i m]

<snip>

<snip drool>

Hmm, still no comment on the nymshifting thing. ;-(

Cheers, T i m

[T i m]

No need, as long as the outputs of the chargers are 'floating' (and they generally are).

This means you can use a single 3 pole connector to do them both at the same time.

I bought a new pair of Lucas AGM GEL for what was Dads TGA mobility scooter when the previous batteries got destroyed by not being charged at all for a long time.

After charging them first individually (on the Optimate4) I put them on the scooter and plugged in it's 24 volt charger but that never seemed to turn off (= go into maintenance mode).

So, had I left it on it would have destroyed the new batteries. ;-(

I've since tested the idea of charging them independently whilst still plugged into the scooter loom using two Optimate2's and they work fine (and both shut off when they should etc).

There could be something wrong with the (new) 24V charger of course but it did actually work as designed on a different pair of 12V batteries (suggesting to me that it's not 'smart' enough for my liking).

And these batteries aren't cheap eh. ;-(

Cheers, T i m

[Nick de Smith]

Thanks for the help.

The Anderson connectors look just the job.

I now have the panels - they are 250W

I'll probably just use 2 panels in series which will give about 70V and 8A charging with full sunlight.

I'll chop off the existing MC4s and replace them with single pole Andersons. All other power connectors will also be Anderson.

Also, two buss bars for the batteries, with each battery using single pole Andersons too allowing easy down/upsizing.

Mains input will be 16A IEC 60309; output likewise. I'll provide a couple of ordinary mains sockets too on the panel.

DC in, AC in and out all to have separate breakers appropriately sized. Each battery string to have inline fuse.

Might provide a earth spike.

A small dry powder extinguisher to be included.