24v Garden fence lights - series or parallel??

[JustaWelshDude]

Hi everyone,

I was wondering if I could get a little advice on a small project I plan to carry out over the next few weeks.

I plan to install 10x 6w GU10 LED bulbs (fitted inside some suitable outdoor light boxes) on each fence post along a 30 metre garden fence, the lights will be powered from my shed where I have an existing modest 12v solar installation.
The shed has a 20W solar panel, 2x 12v 12Ah batteries wired in parallel for 24Ah total, a solar charge controller (cheap Chinese one) and a 12 to 24v boost converter.
I plan to use 24 volts for the fence run.

My question is, should I connect all of the lights in series or parallel? I'm leaning towards parallel because I'm worried that if I connect them in series the current would drop along the cable causing the end lights to dim. Plus the GU10 bulbs are rated as 12 - 24 volts so would presumably be happy about a little voltage drop under 24 volts.

I decided to get the 12 to 24v boost converter because I was worried about the voltage/current drop and due to the length of the run at 12 volts I would need thick expensive cable.

However, before I start my endeavor I'd like a little advice from anyone who has done something similar previously.

Thanks.

 

[telectrix]

for starters, GU10,s are 240V. you need 12V LEDs (MR16) . wirein parallel, calculate voltage drop, and size cable accordingly.

 

[JustaWelshDude]

The GU10 bulbs I intend to use are here ledkia.com/uk/buy-conventional-gu10-led-bulbs/6424-gu10-120-s11-6w-led-bulb-12-24v.html
Which are listed as 12 -24v.

Thanks for the advice though.

 

[littlespark]

That is confusing. (just looked at the website)
What is to stop someone inserting this 12v /24v lamp into a 230v lampholder?
That's why there is different cap types

 

[JustaWelshDude]

Yeah I see your point, it's great for me though, it means I can use some simple and cheap 240v type outdoor downlight boxes and plug in the 24v GU10 bulbs which will be fed from my 24v feed. Just to be safe I think I'll write 24v on the bulbs with a marker pen beforehand.

 

[pirate]

Shouldn't be allowed, imho...

 

[plugsandsparks]

There isn't really enough info to be sure, however these lamps are stating an operating voltage, i.e. 12-24V. When you wire in series you are trying to maintain a constant current, the voltage out of the driver would be well over 24V to drive the necessary current. So you have no choice really but to wire them in parallel and hope the volt drop along the fence does not fall below the minimum threshold voltage of the regulator built into each lamp.
As you dont know either of these variables, its try it and see..

 

[GeorgeCooke]

for starters, GU10,s are 240V. you need 12V LEDs (MR16) . wirein parallel, calculate voltage drop, and size cable accordingly.

Rubbish. GU10 is a type of base GU10 lamps are usually 240v, but can be 120v, 12v or 24v.

MR16 is the size of the lamps multifaceted reflector. (16/8"). LEDs don't usually have a multifaceted reflector.

 

[GeorgeCooke]

That is confusing. (just looked at the website)
What is to stop someone inserting this 12v /24v lamp into a 230v lampholder?
That's why there is different cap types

Intelligence.

 

[littlespark]

Intelligence.

Well that is something sorely lacking in this day and age judging by some of the lash ups we see on here.
Same base for 12v or 230v? Hardly idiot-proof, is it?

 

[James]

Well that is something sorely lacking in this day and age judging by some of the lash ups we see on here.
Same base for 12v or 230v? Hardly idiot-proof, is it?

Edison screw base is used with lamps of many voltages and has been for a long time, I often come across them in machines using 24v, 50v or 110v lamps.

alas, every now and then as you suggest a customer will buy some replacement lamps (230v) from the local shop, screw them in and then call me because they don't work.

 

[solar-energy5]

Could verify whether this calculations are well for solar panels that may be added in the future.I mean can I do this calculation for the installation and add more panels whether it is required?
Solar Panel Installations

 

[davesparks]

That is confusing. (just looked at the website)
What is to stop someone inserting this 12v /24v lamp into a 230v lampholder?
That's why there is different cap types

Nothing stops someone putting it in a 230V lampholder, but that's not any different to 110V, 24V or 12V ES lamps, BC lamps or any of the other standard lamp bases used for different voltage lamps.

Voltage is not the reason for different lampholder types.
Some lampholders are only rated for ELV such as the gx5.3 lampholder used for MR16 lamps.

 

[JustaWelshDude]

Thanks for all the responses guys, for the sake of closure and anyone reading this in the future, this is what I did and what the results were.

I originally used this DC-DC 12v to 24v Step Up Converter and cabled the LED bulbs in parallel which did work ok, but I actually had to change the step up Converter to a different type because the first one I used had a huge inrush current which would trip my 10a WiFi relay.

Then, last week, I noticed the 12v to 24v step up converter had stopped working, so out of curiousity I tried connecting the string of lights directly to the 12v supply (which, I admit I should have tried at the beginning of the project) and it worked!
I haven't noticed any difference in the brightness, the whole string of lights are nice and evenly bright, they do however use a little more current, 5.5 amps @ 12v compared with 4.8 amps @ 24v and no inrush current high enough to trip the WiFi relay.

All 10 of the LEDs are still working 1.5 years later so I do highly recommend them.