Small DIY, Camping/Power Outage Solar System

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247 posts

Master Geek

#1528010 7-Apr-2016 22:01

Got a fair bit of it done, DSE had 7aH SLA batteries 80% off so I grabbed two, not a whole lot of capacity, but will get me started. Essentially everything is done except adding the Solar Panel (pretty crucial bit :P ), adding the 12V lamps and tidying the wiring etc. A lot of it is just bits I had lying around, so not the most tidy:

And yes, the solder "String" holding the Voltmeter is just temporary until I get some M2 bolts.

When I get the Panel I'll charge it up and run the 4x 5watt LED lights to get an idea of usable capacity, and see how long it takes to charge on an Sunny and cloudy day. As the days are getting shorter, it's getting close to a worse cae scenario for charging.

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richms

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#1528043 7-Apr-2016 22:30

I'd suggest grabbing one of the cheap blue "LiPro" hobby chargers - they are great for getting a capacity measurement for lead acid batteries. Used on to find that the brand new jumpstarter from the warehouse was stuffed at 1/4 what its capacity should be, so took it back and swapped for a newer one which was getting 80% which is much better.

How much were they at 80% off?

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RileyB

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Master Geek

#1528109 8-Apr-2016 07:42

I think they where $8 each.

RileyB

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Master Geek

#1533145 14-Apr-2016 18:10

Lights arrived, just need to panel, and to solder some sort of plug/socket onto the lights. My testing shows them to be 2.5W rather then the listed 5W (not surprising as it says 3W under the 5W sticker on them), but considering they cost me $7USD shipped for four of them, I can't complain to much.

richms

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#1534654 18-Apr-2016 05:34

RileyB:

Lights arrived, just need to panel, and to solder some sort of plug/socket onto the lights. My testing shows them to be 2.5W rather then the listed 5W (not surprising as it says 3W under the 5W sticker on them), but considering they cost me $7USD shipped for four of them, I can't complain to much.

They dont have drivers, just resistors so off 12v they will be much lower than when it is at 14.4v for charging, which is when you will get the 5w. Brightness wise stuff all difference tho. If constant brightness is something you need despite charging or being near flat then you may want to get one of those cheap DC DC converters to make it a constant 14.4 v and get the most out of them. I guess you could possibly find a 5v driver for 3 series LEDs and put that in the lamp and remove the resistors, but that would double the cost of them pretty much.

I would suggest anderson plugs for your 12v needs - many cheap clones on aliexpress/ebay or the hobby sites, and you dont have to worry about making them up with the right ends on them since they are all the same. And if you get stuck you can get them from jaycar too.

Richard rich.ms

RileyB

247 posts

Master Geek

#1536742 20-Apr-2016 15:30

richms:

RileyB:

Lights arrived, just need to panel, and to solder some sort of plug/socket onto the lights. My testing shows them to be 2.5W rather then the listed 5W (not surprising as it says 3W under the 5W sticker on them), but considering they cost me $7USD shipped for four of them, I can't complain to much.

They dont have drivers, just resistors so off 12v they will be much lower than when it is at 14.4v for charging, which is when you will get the 5w. Brightness wise stuff all difference tho. If constant brightness is something you need despite charging or being near flat then you may want to get one of those cheap DC DC converters to make it a constant 14.4 v and get the most out of them. I guess you could possibly find a 5v driver for 3 series LEDs and put that in the lamp and remove the resistors, but that would double the cost of them pretty much.

I would suggest anderson plugs for your 12v needs - many cheap clones on aliexpress/ebay or the hobby sites, and you dont have to worry about making them up with the right ends on them since they are all the same. And if you get stuck you can get them from jaycar too.

There bright enough for my needs so I'll probably just leave them as is. If they are advertised as 5W 12v, then shouldn't that 5W be at 12V not 14.4v? Also I would imagine 14.4v would bring them up to the 3W that was hidden under the 5W sticker, rather than 5W :P

The Anderson plugs look really good, I might use them to connect the Solar Panel, and the car lighter socket, but they are probably more than overkill for the 0.21A the lights pull.

richms

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#1536768 20-Apr-2016 15:43

RileyB:

There bright enough for my needs so I'll probably just leave them as is. If they are advertised as 5W 12v, then shouldn't that 5W be at 12V not 14.4v? Also I would imagine 14.4v would bring them up to the 3W that was hidden under the 5W sticker, rather than 5W :P

14.4 * 0.37 =5.328 - So probably a little high for it.

12v usually means car use to most people, so they have to take into account when the alternator is charging. 13.8 is typically assumed to be the norm for a "12v" system. 14.4 is needed to charge some of the newer lead acid types, 13.6 is a typical float voltage for most sealed lead acids.

RileyB:

The Anderson plugs look really good, I might use them to connect the Solar Panel, and the car lighter socket, but they are probably more than overkill for the 0.21A the lights pull.

I chuck them on anything that is 12v ish. There are also plenty of "waterproof" automotive connectors on aliex/ebay - I use them on the trailer on the lights that came with pigtails already on them. No idea how waterproof they really are but have to be better than nothing.

http://www.aliexpress.com/item/2P-waterproof-automotive-Wire-Connector-Plug-2-Pins-Electrical-Car-Motorcycle-HID/1610644651.html

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RileyB

247 posts

Master Geek

#1543032 27-Apr-2016 21:00

Thinking of using RCA jacks/cables for the lights, will 12V ~0.2A be OK over RCA connectors? Seem like the cheapest/easiest connectors for my purpose.

richms

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#1543243 28-Apr-2016 10:10

RileyB:

Thinking of using RCA jacks/cables for the lights, will 12V ~0.2A be OK over RCA connectors? Seem like the cheapest/easiest connectors for my purpose.

No because they have a large sticking out part that has the voltage on them, so if it hits onto something grounded it will short out.

The yellow tipped DC plugs are designed to not have this happen, but even the older style DC barrel connectors will be a hell of a lot better than RCA's for accidental shorts, and you can get them with screw terminals cheap sold for use with CCTV cameras on aliexpress in bags of 50 or so.

Richard rich.ms

RileyB

247 posts

Master Geek

#1543261 28-Apr-2016 10:31

richms:

RileyB:

Thinking of using RCA jacks/cables for the lights, will 12V ~0.2A be OK over RCA connectors? Seem like the cheapest/easiest connectors for my purpose.

No because they have a large sticking out part that has the voltage on them, so if it hits onto something grounded it will short out.

The yellow tipped DC plugs are designed to not have this happen, but even the older style DC barrel connectors will be a hell of a lot better than RCA's for accidental shorts, and you can get them with screw terminals cheap sold for use with CCTV cameras on aliexpress in bags of 50 or so.

I'm not really sure how that is a problem, as only the socket will be live? The only time the long pin on the RCA connector will be live, is when it's in the RCA connector, and it won't short anything in there.

The other problem is, the DC barrel jacks, is there only seems to be PCB mount jacks, and no flush mount jacks I can find.

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#1543266 28-Apr-2016 10:48

I'm considering something similar, but just to keep rarely used 30AH batteries charged, and to provide a little power in an emergency. Would this set of stuff work?

12V 50W poly panel (or a similar one)

Cheap MPPT solar regulator 10A/12V/US24 from ebay, or this even cheaper one for less than US$10. Seems better than the $40 PMW ones in NZ for twice the price. Quality obviously questionable, but cheap MPPT better than NZ sourced PMW?

What cables and connectors would I need?

richms

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#1543286 28-Apr-2016 11:27

It will not be MPPT, it will just be PWM at that price. They use some justification that PWM can track over a small amount to call them MPPT but its not what everyone else calls a MPPT which will get more out of a panel in overcast days etc. All the PWM helps with is when the battery is signifigantly lower than the panel output, will maximize that to a degree vs just putting the panel on the battery and having its voltage dragged down to the flat battery voltage.

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richms

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#1543289 28-Apr-2016 11:35

RileyB:

I'm not really sure how that is a problem, as only the socket will be live? The only time the long pin on the RCA connector will be live, is when it's in the RCA connector, and it won't short anything in there.

The other problem is, the DC barrel jacks, is there only seems to be PCB mount jacks, and no flush mount jacks I can find.

I thought you were taling about using RCA's at both ends of it.

http://www.aliexpress.com/item/50pcs-lot-Copper-5-5mm-x-2-1mm-DC-Power-Jack-Socket-Female-Panel-Mount-plug/32492598609.html

are panel mount DC sockets - gets ones where the pin is recessed quite a way like that since it will reduce the chance of the outside of the barrel shorting the pin to the casing if you fumble it, but they are not the ideal plug for the output end of something because that chance does exist.

Whatever you do, get some few 100mA polyfuses inline with it so you dont have to worry about stuffing about with blown fuses etc.

Something like this http://www.aliexpress.com/item/50pcs-0-65A-250V-650mA-PolySwitch-Resettable-Fuse-Poly-Switch-Fuses-Polyfuse/32542899698.html -not bought those ones, got mine locally but saves hassle since they will come back on if you just disconnect the short for a few seconds so they cool down.

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timmmay

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#1543299 28-Apr-2016 11:39

Given that I'll probably stick it inside a window, and it won't be angled quite right, panel output may be lower. But also given I'm not in any kind of a rush I think that's fine. So do I buy a PMW controller from NZ for $25 odd dollars, or get a cheapy from ebay like I linked to already?

RileyB

247 posts

Master Geek

#1543309 28-Apr-2016 11:47

The solar controller you linked just has compression style clamps, so you can just use bare tinned wire if you want, the other end will depend on your batteries, put they are probably spade type posts. The Solar Panel I think has MC4 connectors, but it would be a good idea to email the store first to check.

For your load, it will once again depend on what you are using for the load.

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