Spotlights and alternator

Thinking of putting a couple of 100w spots on my 93 defender will the alternator be ok adding this extra wattage on its a 200tdi engine.
Thanks.

All depends on the output of the alternator and the load you expect to be drawing.

Two 100W spots are 8.33A each but will obviously be used in conjunction with the headlights (which means all the other lights are also on) and possibly heater, wipers etc.
If total output exceeds your alternator output then you need to upgrade the alternator (and wiring).

Why 100W spots?
I only ask as there are excellent lights out there that use 55W bulbs and out perform 100W units plus of course you have a big choice in LED.

Unless your current alternator is goosed two 100w spots are going to be absolutely fine. Just make sure that the wiring is up to it. Have a look at my tutorial if electrics are not your bag.....

Thanks lads.

Litch said:

All depends on the output of the alternator and the load you expect to be drawing.

Two 100W spots are 8.33A each but will obviously be used in conjunction with the headlights (which means all the other lights are also on) and possibly heater, wipers etc.
If total output exceeds your alternator output then you need to upgrade the alternator (and wiring).

Why 100W spots?
I only ask as there are excellent lights out there that use 55W bulbs and out perform 100W units plus of course you have a big choice in LED.

Click to expand...

Got the chance to buy a a bar cheap and it has a pair of 100w spots fitted.

Just don't use them on the road, cos' it's illegal.

waldershelf said:

Just don't use them on the road, cos' it's illegal.

Click to expand...

Sure about that?

Saltlick said:

Sure about that?

Click to expand...

Spots int the problem the wattage is.

There is a power/lumen limit for headlamps, to prevent oncoming drivers from being blinded by poorly adjusted headlamps. Of course, you could just remove them or change the bulbs for the MOT. Given the often poor state of standard Landy wiring, I'd be installing separate wiring and a relay - otherwise you'll likely burn out your high beam switch on the stalk.

Right, lighting lesson.

When buying lamps, don't go by wattage - not now a days. I can get a 10 W lamp which will give out far more light than a traditional 60W incandescent lamp - go by lumens - it's the only unit which truly represents what a lamp is doing especially nowadays.

This goes for ALL your lamps, house or car - cheap H4 lamps will have a lower lumen count than good branded ones for example. I use Osram and they were like night and day from I think Ring lamps I took out.

Lumens (lm) is the unit used to measure visible light emitted from a source.

Kelvin (K) is the unit used to measure the colour temperature of the source. Halogen down lights are about 2700/3000K, light looks white from about 4000K and 6500K is the blue light you see on HID headlights (no reason for them to be bloody blue - you get 2700K HID lamps)

If a lamp doesn't have a lumen rating on it question it's quality. Phillips 11W CFL lamp (energy saver) widely available from supermarkets and B&Q is 600 lumens for the 2700K version. A good old fashioned 60W lamp (depending on manufacturer and clear or opal) was about 600 lumens.

When buying lamps consider colour temp, I hate seeing mixed colour temperatures in a space. Nice warm lighting in a living room then a bright near blue lamp burning away in the pendant light... Looks awful and these people must feel cold! Nice white bathrooms with lots of chrome look great under lots of 4000K light, exposed wood and darker colours look better with warmer light.

So basically shop around wisely for your spotlights and lamps and you can do so much more with less energy, also consider quality fittings with good optics and reflectors - 50W can do a hell of a lot more in a good light than 100W in a cheap eBay spot light.

So look out for good 55W lamps which may be as bright as a cheap 100W - yes really.