150W monocrystalline with PWM vs 200W polycrystalline with MPPT

[antobag]

So that was accomplished with (1) of the 200w Poly panels and the entry level Mppt controller?
thanks

Yes, it was actually 2 x 100W poly panels (connected in parallel) alongside the entry-level "Eco-worthy" MPPT controller.

I'm glad to hear that things went well, I was worried about how well a new solar setup would hold up to Wales in the winter.

Thanks Bucho. The person who owns the hut was so impressed they actually want to buy the panels off me!

[Bucho]

Just to let you all know, I've returned from the Welsh mountain hut in which I was using the 200W solar panels discussed above. I was there for 40 days and 40 nights in the end (an unintentionally precise amount of time), and the solar system that I constructed using all of your help and knowledge was absolutely fantastic.

I'm glad to hear that things went well, I was worried about how well a new solar setup would hold up to Wales in the winter.

[LETitROLL]

Just to let you all know, I've returned from the Welsh mountain hut in which I was using the 200W solar panels discussed above. I was there for 40 days and 40 nights in the end (an unintentionally precise amount of time), and the solar system that I constructed using all of your help and knowledge was absolutely fantastic. The weather ranged from thick mist to clear blue skies, from heavy snowstorms to bright sunshine, and the panels performed brilliantly throughout - I powered my laptop, phone, lights, music equipment, etc and never let the battery drop below 50% charge (most of the time it stayed above 70%). There were admittedly some days where I had to leave the battery alone to charge, but these were few and far between.

I just wanted to let you know that the vast knowledge and experience you all shared with me is very much appreciated. I came to this forum knowing almost nothing about solar power and managed to set up and use a safe and efficient off-grid system that performed really well - even in winter in the notoriously-overcast country that is Wales.

To everyone who helped me in this thread and in others, thank you. I don't know what I would have done without you guys

So that was accomplished with (1) of the 200w Poly panels and the entry level Mppt controller?
thanks

[antobag]

Thank you everyone!

Just to let you all know, I've returned from the Welsh mountain hut in which I was using the 200W solar panels discussed above. I was there for 40 days and 40 nights in the end (an unintentionally precise amount of time), and the solar system that I constructed using all of your help and knowledge was absolutely fantastic. The weather ranged from thick mist to clear blue skies, from heavy snowstorms to bright sunshine, and the panels performed brilliantly throughout - I powered my laptop, phone, lights, music equipment, etc and never let the battery drop below 50% charge (most of the time it stayed above 70%). There were admittedly some days where I had to leave the battery alone to charge, but these were few and far between.

I just wanted to let you know that the vast knowledge and experience you all shared with me is very much appreciated. I came to this forum knowing almost nothing about solar power and managed to set up and use a safe and efficient off-grid system that performed really well - even in winter in the notoriously-overcast country that is Wales.

To everyone who helped me in this thread and in others, thank you. I don't know what I would have done without you guys

[jimindenver]

I'm planning to run my battery down by only 30% D.O.D each day, and by 50% max. I'll shut it off if it gets near this amount. Would leaving it at around 40% D.O.D for more than two days cause a lot of long-term damage? Definitely don't want to be running them flat and buying new ones!

Your batteries should be discharging, recharging or resting at full charge. Leaving them sit partially charged is damaging.

The time to light the candle and cut back on the puter time is when the clouds roll in and you still have battery power to conserve. Not run at full speed till there is nothing left.

In our trailer the big loads can drain the bank in short order with out the solar assist. So when the clouds roll in the big inverter goes off. The TV is limited to a few hours a day IF there is something to watch. Doing so means the banks will last a week if they had to, not that I would allow it.

One way or another you need a back up means of charging be that a generator, your trucks alternator or for us the last resort is turning the truck around and using jumper cables.

[antobag]

When you have several cloudy days, the batteries are low, and you can't run anything, they (batteries) are well on their way to the grave. sitting for 48 hours, nearly completely discharged, the batteries will sulfate and die. Day 2, is when I run my genset to re-bulk the batteries, because this last Nov & Dec, we had 5 weeks of solid clouds. The choice is to, on the first day of clouds, shut your batteries off while they are still full, or continue to use the system and recharge with the generator.
[ATTACH=CONFIG]5527[/ATTACH]
The third option, run the batteries flat, and then buy new ones.

I'm planning to run my battery down by only 30% D.O.D each day, and by 50% max. I'll shut it off if it gets near this amount. Would leaving it at around 40% D.O.D for more than two days cause a lot of long-term damage? Definitely don't want to be running them flat and buying new ones!

[Mike90250]

... I'm prepared to have a few unproductive laptop-free days and a few candlelit evenings if I need to give my battery time to recharge, so hopefully I won't be needing a generator. Although I'll probably be eating my words ....

When you have several cloudy days, the batteries are low, and you can't run anything, they (batteries) are well on their way to the grave. sitting for 48 hours, nearly completely discharged, the batteries will sulfate and die. Day 2, is when I run my genset to re-bulk the batteries, because this last Nov & Dec, we had 5 weeks of solid clouds. The choice is to, on the first day of clouds, shut your batteries off while they are still full, or continue to use the system and recharge with the generator.
weather-rain.jpg
The third option, run the batteries flat, and then buy new ones.

[antobag]

Good luck, a DC charger for the laptop sounds like a great idea, but I think you still need to have a conversation about generators.

Thanks for the luck, I'm sure I'll need it! I'm prepared to have a few unproductive laptop-free days and a few candlelit evenings if I need to give my battery time to recharge, so hopefully I won't be needing a generator. Although I'll probably be eating my words when I'm stuck in a dark hut on a Welsh winter's night with nothing but a few books to keep me occupied... on second thoughts, anyone know of any good "cabin fever preparedness" forums?

[Bucho]

You're absolutely right. I guess I'll stick to the car charger for now - the company (Lavolta) have some pretty good reviews, so hopefully the adapter will work well with my system.
Thanks again for all the help.

Good luck, a DC charger for the laptop sounds like a great idea, but I think you still need to have a conversation about generators.

[antobag]

Isn't the plug in on that the power source itself, best you can do is make sure the wiring and receiver is up to snuff.

You're absolutely right. I guess I'll stick to the car charger for now - the company (Lavolta) have some pretty good reviews, so hopefully the adapter will work well with my system.

Thanks again for all the help.

[jimindenver]

Isn't the plug in on that the power source itself, best you can do is make sure the wiring and receiver is up to snuff.

[antobag]

To show how direct wiring can make a difference.

Long ago we bought a small 12v 200w auto drip coffee maker. Trying to use it plugged into a cigarette lighter while on the road took so long that we deemed it a failure and it was stashed away. When I was testing our 230w portable while camping a few years ago it was all I had that could put a big enough load to push the system. I didn't expect much and was blown away when it made it's pot in about the same time a regular auto drip does while pushing the system to over 16a.

So hooking up something properly with ample wire, the shortest distance and fewest connections makes a difference.

Thanks jimindenver. So would you recommend that I go directly from my battery to a DC-DC 12V-19V step-up adapter (ie. this: http://www.amazon.co.uk/In-Car-Charg...ptop+charger)? If so, I assume I'd have to cut the cable of the adapter in order to attach it directly to the 12V battery?

[antobag]

searching for 'cigarette socket' i saw this:

http://www.amazon.co.uk/Practical-Motorbike-Tractor-Cigarette-Lighter/dp/B00C7MXQAU/

Doesn't have a fuse - but has a link to buy a fuse holder. And together they'd still be cheaper than the one you found.

I don't see a problem with wiring 2 or 3 sockets to the same battery. My car has 3 sockets, plus all the normal car things (lights, radio, etc)

I do think you need to be careful about not using so much power that you drain the battery. Especially since I think you're talking about only charging it from the sun - so you won't have a lot of power to recharge it.

My reasoning for a hard-wired solution is that then everything is solidly put together - I don't have to worry about spring loaded clips that aren't working as well as I want. I haven't used these clips - but I know from jumper cables that getting a good connection to a battery via spring-loaded clips can be a PITA. Maybe it won't be as bad with cleaner things to connect to (not dirty from years of being under the hood of a car)

I was originally avoiding that socket as it is shipped from China (just me being impatient!) but I just noticed that they have a UK distributor for only a few quid more AND there's two supplied, so I've gone ahead and bought it. Much cheaper than the single £9.99 one I found!

You're right, I think I'll stick to two sockets for now. I assume it'd be fine to go ahead and stick 5A fuses in them?

[jimindenver]

To show how direct wiring can make a difference.

Long ago we bought a small 12v 200w auto drip coffee maker. Trying to use it plugged into a cigarette lighter while on the road took so long that we deemed it a failure and it was stashed away. When I was testing our 230w portable while camping a few years ago it was all I had that could put a big enough load to push the system. I didn't expect much and was blown away when it made it's pot in about the same time a regular auto drip does while pushing the system to over 16a.

So hooking up something properly with ample wire, the shortest distance and fewest connections makes a difference.

[foo1bar]

Thanks foo1bar. What are the benefits it being direct wired over clip-on? Also, would it be dangerous to use one without a built-in fuse?

The best thing I've found on the internet in the UK is this: http://www.amazon.co.uk/Waterproof-C...ref=pd_cp_ce_1

Would I be able to wire 2 or 3 of these to the same battery?

An Amazon reviewer has mentioned that the cables are too small to be used with anything more than the supplied 2A fuse. How true is this? I would most likely need to have at least 5A going through (in order to get 60W to power my laptop (which runs at 90W max)).

searching for 'cigarette socket' i saw this:

http://www.amazon.co.uk/Practical-Motorbike-Tractor-Cigarette-Lighter/dp/B00C7MXQAU/

Doesn't have a fuse - but has a link to buy a fuse holder. And together they'd still be cheaper than the one you found.

I don't see a problem with wiring 2 or 3 sockets to the same battery. My car has 3 sockets, plus all the normal car things (lights, radio, etc)

I do think you need to be careful about not using so much power that you drain the battery. Especially since I think you're talking about only charging it from the sun - so you won't have a lot of power to recharge it.

My reasoning for a hard-wired solution is that then everything is solidly put together - I don't have to worry about spring loaded clips that aren't working as well as I want. I haven't used these clips - but I know from jumper cables that getting a good connection to a battery via spring-loaded clips can be a PITA. Maybe it won't be as bad with cleaner things to connect to (not dirty from years of being under the hood of a car)