solar panels

Discussion in 'Mech Tech' started by redoxide, Jan 10, 2019.

  1. Not looking to live in the van full time, but interested in sourcing decent solar panels for permanent fitment to the glass fibre top.

    would prefer lightweight flexible type , I think ! and a good power input, which would bring me to the next component, a decent deep cycle battery..

    whos got what ? whats a decent power output ,

    not looking to supply the grid, just power a JK fridge, work some LEDS and maybee a small TV and possibly a 12 v CD player ..


    PS I have a split charge system which works fine but unless you start the van up your gonna run out of power .. Ive read that you cant hook the solar ito a battery that subject to spit charge charging ? any ideas on that info ?
  2. Try a browser search initially as there is a tonne of information hidden in the forum archives. That should get you started, then take it from there with specifics...:thumbsup:
    1973daisey and redoxide like this.
  3. Oh and ref the battery charging, a good quality solar charge controller will ensure that current flows to the battery only when it needs it.
    Same as a 230v mains smart charger, or a voltage sensing split charge relay.
    My simple head considers the leisure battery as the heart of the system.
    Therefore it's a marine 110amp unit. Lower capacity than some, but heavy duty construction means thicker plates, more duty cycles and longer performance.
    Big capacity simply means you have more to top up! I had to chop the wheel well to fit it so its a compromise, but worth it.
    My 3 charging sources are :
    1.from the alternator, via a durite VSR
    2.from a ctek 10 amp smart charger when hooked up
    3.from 180w total flexible Global Solar panels via a mppt charge controller.

    Simple, but the best kit I could afford. Buy cheap and you may regret it.
    We can live off that, and have done.
    Hope that gets you started, there's a lot of choice and opinion out there...
    Last edited: Jan 11, 2019
    CollyP, Pickles, Day and 4 others like this.
  4. We never use a hookup.
    We're running 4x80 Watt flexible solar panels on the roof, through a Victron 75/15 MPPT Charger and into 2 x 130Ah Lithium Batteries.
    Charging from the engine comes though a Victron split charger. It's an expensive setup, especially the batteries, but I think we've hit our comfort level now running a Waeco fridge and an Eberspacher heater being the main power draws.

    If I was going to recommend anywhere to spend money, it'd be a decent Charge controller. I'm happy with the Victron one we have, and the geek in me likes the bluetooth app that lets me see what its all doing from my phone.

    Winter charging in the UK is the hardest, that's why we went overboard on the solar panels. If you're only likely to be using your van in the summer then you can get away with probably on 100watt panel.

    And with regard to the can't hook up solar to a split charge system, I don't think that's the case. Mine is exactly that way.
    Bulletooth and Day like this.
  5. Do you have any pictures of the kit in situ @Weasel ?
    I'd be interested to see where you've put it all :thumbsup:
  6. I'll take some but its not very photogenic....
    I have one of the roof
  7. [​IMG]

    Sent from my iPhone using Tapatalk Pro
    CollyP and theBusmonkey like this.
  8. [​IMG]

    These were the batteries, 2nd hand but low cycles. I’ll get some photos of them in situ later.
    We’ve sacrificed some storage in the van but if we’ll see if it becomes an issue. I’d rather lose a spare gas bottle than run out of electric.

    Sent from my iPhone using Tapatalk Pro
    pkrboo, theBusmonkey and Pickles like this.
  9. Are these significantly better and more expensive than standard leisure batteries?

    Do you solar on the boat, it's something that I might have to consider on the yacht.
  10. Actually I don't. Both buses have more modern systems than the boat, despite the boat being our home.
    The 220 ah we have on the boat leisure system is enough to allow us to be stationary for 4 or 5 days but the reality is that when we're travelling the system we generally move for 4 hours a day which is enough to allow the old Lucas 36amp alternator to recharge both starter and LB.
    I have a genny for the obligatory hairdryer and straighteners...
    Hook up in the marina costs us about 40 quid per quarter. That covers our 230 requirements for tv, radial sockets and the battery charger.
    Water pumps, one of the tv's and lighting all run off the dc system and we have the multi fuel stove for heat and gas for instant hot water.

    The cost of a decent marine solar set up wouldn't pay back for about 5 years, by which time the batteries would be tired and we'd be looking at component costs again! Top kit is still expensive as you know if the word 'marine' prefixes anything:rolleyes:
    The van philosophy is different in that we get off the beaten track and rarely use campsites in either the bay or the T3.
    The system on the bay allows indefinite stand alone travel in northern Europe whereas the 100w on the T3 means we have about 3 days with the eber and fridge without decent sun before we have to run for a couple of hours.
    Solar is ideal for a yacht where there is limited engine charging I would think?:thumbsup:
    Last edited: Feb 4, 2019
    Day likes this.
  11. I consider them better on two fronts.. they can safely discharge to almost nothing, certainly 80% discharge is normal. And they are a lot lighter than a lead-acid battery. So I have 260Ahrs of usable battery for the weight of my previous 146Ahr Lead battery (of which I could only safely use 50% so really 70Ahr).

    The downside is the cost. New these are probably £2000 each. Second hand I got them for £360 each. Still expensive but my previous lead battery was £260 new so I thought it was worth the "upgrade". You can get some 100Ahr Lithiums for about £600 new and I umm/ahh'd about those for a while until I spotted these.

    One other downside is they are only rated to 150 amp draw, but I don't think that I'll ever have a need for that. If the inverter burst up to 2000watts, that'd be the max the batteries could cope with, but I don't plan on plugging anything that massive in to that! A travel hairdryer at 700watts makes me wince.
    pkrboo and theBusmonkey like this.
  12. Good score on the batteries. Does the Victron split charger compensate for any difference in the charge profiles of the leisure battery vs the starter battery?
    I don't know much about lithium tech...
  13. I have the Victron Cyrix-CT at the minute (left over from when I was running Lead-Lead) and the voltages seem OK . To be honest, I need to do some more research here myself as I'd rather not fry them. As I understand anything under 14.6 is Ok to charge them, 14.6 being too much. The solar charger has a Lithium profile that provides a short "absorption" stage at 14.2 volts and I've seen it hit that consistently. I've never seen that much coming from the alternator. Victron do a Cyrix-Li-CT which might have more appropriate voltages and I will probably switch to this to be sure.
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  15. Yes what with autopilot, gps, vhf radio, nav lights, etc it's surprising how much battery you need. Still getting used to the boat though.
    theBusmonkey likes this.
  16. Coincidentally I was having some correspondence with a chap on FB this morning about that very bit of kit.
    I'm still a bit confused @matty what the benefit is over a VSR and a mppt controller apart from it's a one box solution.
    Can you shed any light bud as the chap simply said it gives a more stable charge voltage to the LB...?
    Edit: having reread the spec again I now get it will allow different battery types in the system. Anything else?
    Last edited: Feb 4, 2019
  17. It seems like it will also keep your starter battery topped up using the solar input when the leisure battery is fully charged. Reviews saying it plays nicely with the ctek ac/dc charger too. I hadn't come across it before so watching this thread with interest.

    theBusmonkey likes this.
  18. So does a decent solar output through an mppt charge controller via a 2 way VSR. :confused:
    It's big bucks but I love my tech and would like to be able to justify it as an upgrade.
    Just need Matty to convince me coz I know he's had a few years experience with it.
    mikedjames and matty like this.
  19. I’ve had it for around 4 years it seams fine.

    I have a 80w panal on the roof and a 7 year old 100amp battery that could do with being replaced it feeds a compressor fridge, propex heater, water pump, lights and radio and it normally runs fine for 5 days witch suits us as we normally move on every few days.

    What I have noticed it doesn’t need the engine to run for long to charge up the batterys.
    I believe it’s because it alters the loading on the alternator so it gets maximum charge rather than it tailing off as the battery charges.

    The main reason for getting it was I like it all simple and out of sight , you do need some biggish cables feeding it
    theBusmonkey likes this.
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