oap Posted September 11, 2009 Share Posted September 11, 2009 I have two 100 watt lights on the bullbar and two 50 watt work lights on the back of my 10 year old td5. There has been no problem with these so far even though I can hear the engine working harder when the two front lights are on. I would like to add a light bar above the windscreen with four 50 watt lights and that will be the last lights Ill add to it. I might hard wire a sat nav and rear view camera sometime hopefully. So with a standard battery and alternator will it work or do I need a better system? Quote Link to comment Share on other sites More sharing options...
western Posted September 11, 2009 Share Posted September 11, 2009 2 x 55w bulbs will draw about 10amp so 2 x 100w will need about 20amp depends on the condition/charge of the battery, it maybe asking the alternator for more charge than the alt can supply, hopefully a more brainy electrical guru will pop in & assist. Quote Link to comment Share on other sites More sharing options...
oap Posted September 11, 2009 Author Share Posted September 11, 2009 2 x 55w bulbs will draw about 10amp so 2 x 100w will need about 20amp depends on the condition/charge of the battery, it maybe asking the alternator for more charge than the alt can supply, hopefully a more brainy electrical guru will pop in & assist. Thanks for the reply Western, everything battery and alternator are as good as new but standard. I want to take another 20amp off it then so 50 amp more than than Landrover had in mind and as I said a few small bits in the cab later on. Any electrical guru out there that can say yes or no? Quote Link to comment Share on other sites More sharing options...
ajh Posted September 11, 2009 Share Posted September 11, 2009 Fit HID conversion bulbs and you can cut that draw dramatically. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 12, 2009 Share Posted September 12, 2009 Yes and no - depends on what you are doing and what alternator is fitted. Add up your loads - if you have everything on you might have say - 50A from all your banana republic searchlights About 20A from heated rear screen (guess) About 10A from fan motor if on full speed About 15A from all the other main lights That's 95A on a cold dark night without anything else being on - radio, fridge in the back, heated seats if fitted etc etc. Air con will suck a load out - maybe 30A with the fans running - if you have that. Even with the Td5 alternator which I think is 120A, the basic selection I started with above doesn't put much back into the battery so you are on pretty thin ice. If your vehicle has a/c you are through the ice and up to your neck. The battery condition doesn't have much to do with it - you either have more alternator capacity than your load needs or you don't, and if you don't you are heading towards electrical death very quickly. Quote Link to comment Share on other sites More sharing options...
oap Posted September 12, 2009 Author Share Posted September 12, 2009 Yes and no - depends on what you are doing and what alternator is fitted. Add up your loads - if you have everything on you might have say - 50A from all your banana republic searchlights About 20A from heated rear screen (guess) About 10A from fan motor if on full speed About 15A from all the other main lights That's 95A on a cold dark night without anything else being on - radio, fridge in the back, heated seats if fitted etc etc. Air con will suck a load out - maybe 30A with the fans running - if you have that. Even with the Td5 alternator which I think is 120A, the basic selection I started with above doesn't put much back into the battery so you are on pretty thin ice. If your vehicle has a/c you are through the ice and up to your neck. The battery condition doesn't have much to do with it - you either have more alternator capacity than your load needs or you don't, and if you don't you are heading towards electrical death very quickly. Thats the thing I will never have them all on at once and I dont have a heated rear screen air con or heated seats, its like a fridge in the back espcialy in Winter. So Id say 65 maybe 80 amps max at once and not often, from a 120 amp alternator. Is that safe? Banana republic search lights? Your putting me off the idea of the light bar now. Quote Link to comment Share on other sites More sharing options...
western Posted September 12, 2009 Share Posted September 12, 2009 Fit HID conversion bulbs and you can cut that draw dramatically. not legally on a UK vehicle that wasn't factory built without HID lights, the parent vehicle must have self levelling suspension & headlight wsh & automatic load adjustment to keep the lights in the correct alignment. Quote Link to comment Share on other sites More sharing options...
ajh Posted September 12, 2009 Share Posted September 12, 2009 not legally on a UK vehicle that wasn't factory built without HID lights, the parent vehicle must have self levelling suspension & headlight wsh & automatic load adjustment to keep the lights in the correct alignment. Would that not only apply to headlamps? The aux lighting could be HID could it not since that is not for road use anyway? You could also reverse wire the headlamps so that the the HID are the high-beams if the rules are like here where they are also not for road use. Or fit some LED headlamps Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 12, 2009 Share Posted September 12, 2009 You can fit anything you like lighting wise as long as you don't change the standard headlamp arrangement etc. it doesn't matter if you bolt a WW2 searchlight to the roof as long as it doesn't come on with main beam at MOT time. Quote Link to comment Share on other sites More sharing options...
western Posted September 12, 2009 Share Posted September 12, 2009 would be OK for off public roads use but byways & non classified roads are still public highways & are subject to the same normal tarmac road laws, not many use lights at playday/off road sites, so entirly up to the vehicle owner if he wants to pay out for expensive lights. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 12, 2009 Share Posted September 12, 2009 You can fit anything you like lighting wise as long as you don't change the standard headlamp arrangement etc. it doesn't matter if you bolt a WW2 searchlight to the roof as long as it doesn't come on with main beam at MOT time. ^^^ now that would look silly but somehow cool Quote Link to comment Share on other sites More sharing options...
Aragorn Posted September 13, 2009 Share Posted September 13, 2009 As has been said the alternator is what you need to worry about, not only the unit itself, but the wiring to it and its earthing too. The "charge" wire is often too small on older vehicles and often wont even flow the alternators max rating. I had an astra which would register a maximum of about 13v with all the electrical gubbins in the car turned on and the engine at 2500rpm (alternator wont produce its rated output at idle) I replaced the charge wire that ran between the alternator and the starter with a much fatter one and that climbed to 13.7ish, still wasnt happy so i tried a jump lead between the alternator casing and battery negative and it went up to 14v. Replaced the braided earth strap with another fat wire and that cured it. You can also get driving lights (ie 7" spots or whatever) that come with HID's from the factory. These would be fine to use. The only issue with HID conversion kits is where your retrofitting them to a vehicles dip beam. The best way to monitor it would be to fit a voltage meter connected across the battery terminals and see what happens with the lights on, if it drops below its regulated 14v then the alternator is struggling either due to insufficient revs, or because its exceeding its max current output. Quote Link to comment Share on other sites More sharing options...
oap Posted September 13, 2009 Author Share Posted September 13, 2009 Thanke Aragorn, a lot of info there. Ill see how good that charge wire is. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 14, 2009 Share Posted September 14, 2009 Bear in mind a 120A alternator may only make 60A or less at idle speed, that's before losses. 120A is going to be the "flat out at 3000rpm+" rating. Really you don't want to be running so close to your alternator's max output at any time, the alt should be able to happily run the car at all times. Good earth & power cables direct to the battery, and replacing knackered earthing braids can make a big difference. Fitting fewer, better lights or HID's is another option. Being a bit selective is also worth doing - rather than one switch firing up 10 lights pointing in assorted directions & with different spreads, have a couple of switches and only light up the bits you need. Quote Link to comment Share on other sites More sharing options...
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