New Solar Panel pictures - Goal Zero

[dangerman]

I got it from eBay, here, and had it delivered to my family in California. http://www.ebay.com/itm/161510223452?_t ... EBIDX%3AIT

GZ have it on their website for $54.99 http://www.goalzero.com/p/20/boulder-15-solar-panel/. I bought the refurb from eBay, not because it was $5 cheaper, but because it was easier to pay via paypal than mess around with my UK credit cards.

The connections they come with plug directly into GZ powerpacks and the powerpacks have charge controllers build into them. So yes, you can just plug anything you want into it and charge it up, but phones and standard battery banks don't regulate and so the panel can potentially discharge (or overcharge/damage) them if you leave them connected. Yesterday I gave my phone (3000mah battery) a full charge in just over two hours from this panel with a 12v 2.1A USB outlet and didn't use a charge controller. But I kept moving the panel to keep it pointing directly at the sun and disconnected it as soon as it was fully charged. There are similar demos I've seen of this (or similar panels) where people show you how the wattage delivery works with a little USB fan.

I've also got a Guardian 12v adapter which is also a charge controller http://www.goalzero.com/p/156/guardian- ... controller, this lets me connect the solar panel to any 12v battery I like. It's a nice set up - the Guardian has a little indicator to let you know when the battery has a full charge, so I just swap it around my few batteries to maintain them.

[DustyDog]

Could it be used to charge a leisure battery, thinking of camping, when i cant have it plugged in to charge and also to charge battery during a power cut, would i need one of those gizmos that stop the battery from draining when connected to the panel, sorry to be a idiot with these things.

[dangerman]

Yep, Boulder 15 and a Guardian charge my leisure battery. But I got a bargain on this I think, you may be better buying a non GZ version that will cost a lot less. Here's one on eBay for around the £50 mark.

http://www.ebay.co.uk/itm/20w-Solar-Pan ... 4ad1d66aae

I don't know who made that solar panel, I just searched for it and this came up. But that has 20w potential power output (5w more than my GZ one). It looks good to me. There are loads of options around to be honest. If I were you, I'd keep reading around on the subject and maybe pop into Maplin for some advice. You should try to work out what your power needs are so that you can buy the right powered of solar panel.

What I like about the Goal Zero stuff, if you decided to go down this route, is that they're very light and seem to be incredibly robust - good for leaving outside for keeping batteries topped up and then chucking it into your bags for when you go camping or if you need to evacuate in a rush. If you buy more than one (which I might if another bargain comes up) you can chain them together to increase power. Not sure if other solar kit is as easy to use.

[Hamradioop]

Most solar panels come with a blocking diode, this is to prevent the panel drawing power from the battery when there is no light. A charge controller is always a good thing to have though.

[dangerman]

Ah! I'm learning too! It looks like the boulder has a blocking diode - which means I could just leave my phone or whatever plugged into the USB. Win!

[Yorkshire Andy]

Ah! I'm learning too! It looks like the boulder has a blocking diode - which means I could just leave my phone or whatever plugged into the USB. Win!

does it have a charge regulator? if not whats giving you a clean stable 5v to the USB port?


im very cautious about charging modern lithium derived battery's as if they over charge / over volt they really ruin your day...

https://www.youtube.com/watch?v=pizFsY0yjss

[dangerman]

Actually, no. There isn't anything like that and so I imagine there could be a potential problem if you're not watching it. As I say though, I took my phone off charge pretty much as soon as it hit the 100% mark. I'll be careful about it, but fortunately my phone has a removable battery and they're only a few quid to replace if I ruin it.

The panel isn't really designed to be used this way, I think GZ just offer it as an option to make the kit more versatile. I've seen people using their 12v outlets just to power fans or mini refrigerators directly - that kind of thing.

[Yorkshire Andy]

Could it be used to charge a leisure battery, thinking of camping, when i cant have it plugged in to charge and also to charge battery during a power cut, would i need one of those gizmos that stop the battery from draining when connected to the panel, sorry to be a idiot with these things.

See here
viewtopic.php?f=38&t=11070&hilit=bosch+ ... r&start=10

First you need to work out your demand then you can spec a battery and charger / solar panel


Kiss :

You want to run a 2a led light for 2 hours you need 4ah of useable battery power

Saeled lead acid or lead acid shouldn't be discharged more than about 50% total capacity so for the above lighting would need a minimum of a 8ah battery as an absolute minimum size

Which if you need to put your 4amps back in any your solar panel can charge at 1a on a sunny day you need 4 hours of bright sunshine...

But on a cloudy rainy day it might only put out 200ma {milliamps)

So at 200ma it would take 10 hours to put 4a back {4a = 4000 ma)


Beware of cheap panels which state a high wattage or ampage. Which is probably measured at mid day on the equator

Ideally you want a charge controller which is smart in terms of charging eg PWM (PULSE WAVE MODULATION)

there's lots of reading if you Google battery university

[DustyDog]

Cheers Andy, have seen some on ebay and amazon, ebay is 20 watt and comes with a pwm controller, amazon is a 50 watt, but is more expensive, just using for camping and backup, with inverter, will look at battery uni, thanks.

[Hamradioop]

MPPT Charge Controllers

These charge controllers give approx 30% more power than a PWM charger and you can connect high voltage panels to lower voltage battery banks.

In a normal charger the battery acts as a resistor reducing the amount of power you can get out of the panels, these chargers use Multi Power Point Tracking (MPPT) which keeps 2 separate circuits for the panels and batteries allowing upto 30% more power to be collected from the panels.

They are more expensive than PWM contollers a 10amp PWM charge controller can be bought for about 10 pounds on line where as a MPPT 10amp controller will cost around 55 pounds

A short beginners guide can be found here http://www.bimblesolar.com/beginnersguide