Deesider Posted August 29, 2015 Share Posted August 29, 2015 We have LED string lighting above the overhead lockers in our 2013 Autotrail Apache 632. There are about 5 separate lengths of this lighting and in each section a number of "bulbs" are not lit and even more annoying a number of "bulbs" in the string flicker. Autotrail advise us that this may have been caused by a spike in the current due to over voltage and that replacement is the only remedy. I am unsure if replacement will not result in the same thing happening again and wish to know if anyone else has had similar problems and if so how they fixed it. Link to comment Share on other sites More sharing options...
Robbo Posted August 29, 2015 Share Posted August 29, 2015 I've read on another forum that flickering of the LED string can sometimes be caused by the switch becoming overheated. So, first check if the switch is getting hot. Link to comment Share on other sites More sharing options...
armstrongpiper Posted August 29, 2015 Share Posted August 29, 2015 Some LED strips in our 2008 Tracker began to flicker, and I eventually bought some LED strips from LED Hut (on the 'net'). They offer a choice of colours, 'warm' white etc. Easy to fit and no further trouble. Neil B. Link to comment Share on other sites More sharing options...
David Dwight Posted August 29, 2015 Share Posted August 29, 2015 Deesider. Is your Autotrail still under AT warranty if so its a warranty job, if the leds are labcraft then they are under ladcraft warranty as well. We had a similar problem on are Excel they were replaced by AT. Link to comment Share on other sites More sharing options...
Robbo Posted August 29, 2015 Share Posted August 29, 2015 I don't think Autotrail are correct in saying the problem is due to spikes in the system. You might get spikes from the 240 volt supply to the inboard charger. However, the LED's are powered by the 12 volt leisure battery (which smoothes out any possible spikes), so spikes are virtually impossible, in my view. I understand that LED's are capable of running from quite a wide range of voltages, so 12 volts to 15 volts would be in the acceptable range which is normal for motorhomes. Link to comment Share on other sites More sharing options...
Charles Posted August 30, 2015 Share Posted August 30, 2015 It's caused by cheap Chinese LEDs. Replace with high quality ones and they will last much longer. We looked at a new Autotrail at Brownhills and were put off by flickering LEDs Link to comment Share on other sites More sharing options...
ken the kontiki Posted August 30, 2015 Share Posted August 30, 2015 Robbo - maybe it was my thread you read on another forum? We installed some LED strips and the flickering was indeed caused by the switch. However, we'd mistakenly installed a 240v switch and the contacts proved unreliable. Having now installed a suitable 12v switch, the flickering has stopped. Wouldn't have thought AT could make the same mistake but bypassing the AT switch might prove if it's the switch or LEDs which are at fault. Link to comment Share on other sites More sharing options...
Guest Peter James Posted August 30, 2015 Share Posted August 30, 2015 Mine is a self build using the cheap 12 volt LEDs from Hong Kong via ebay. I used 240 volt switches no problem, and can see no reason why they would work better wth 12 volt switches. I try to remember to switch them off before starting the engine when the voltage rises to about 14.6 volts, but sometimes forget, which is probably why some individual LEDs have flickered and expired. I doubt if paying more would get me different LEDs. I think it would just make it irritating when they blow and have to be replaced. I put this down to being like light bulbs, which are usually excluded from any guarantee because you never know how long they will last, and the maker has no way of knowing how much use you have had out of them, or what voltage you have put through them. Link to comment Share on other sites More sharing options...
ken the kontiki Posted August 30, 2015 Share Posted August 30, 2015 Does this thread in MH Facts shed any light? http://forums.motorhomefacts.com/182-electrical/123444-flickering-led-light-strip.html Link to comment Share on other sites More sharing options...
Deesider Posted September 3, 2015 Author Share Posted September 3, 2015 Thanks for the above responses and particularly Armstrongpiper's suggestion to look at LEDHUT. From them we purchased some IP20 warm white leds and my wife and I fixed them on top of the existing plastic tube lighting (disconnected) with their self adhesive backing. The immediate verdict is a brilliant improvement with no flicker. We have not yet used them for any length of time but so far very good. At £4.80/m they are a better bet than AT's quote of £15.90/m for a direct replacement. Link to comment Share on other sites More sharing options...
Charles Posted September 3, 2015 Share Posted September 3, 2015 LEDs don't take much current, I lit a whole 5m reel off a 1a bench power supply just to test them. Any switch that isn't up to switching a few LEDs is faulty especially a mains switch. The faulty switch in the linked post above had a resistance across its contacts which gave a voltage across the contacts, Times this voltage by the current draw (P=VxI) and you have a Wattage being consumed by the switch, and that's why it got hot. I've just put a strip of 30 in our MH wardrobe. They're ok for now but on hook up the voltage is 13.8v so it might shorten their lives slightly. For one's in the main area though you could put a resistor in line with them to protect against a higher voltage. They only cost a few pence each. Link to comment Share on other sites More sharing options...
mgnbuk Posted September 3, 2015 Share Posted September 3, 2015 Robbo - 2015-08-29 10:37 PM I understand that LED's are capable of running from quite a wide range of voltages, so 12 volts to 15 volts would be in the acceptable range which is normal for motorhomes. That is not the case on the Led strings I have worked with, which have no active regulation of the supply voltage. These typically have the Leds in blocks of three, with the three diodes being in series with a small resistor whose value is calculated to limit the current through the Leds at the stated supply voltage. Put a higher voltage across the string & the current through the Leds will be too high - they will not get any brighter (unlike a filament lamp) but they will run hot and fail early. Being in series, only one out of the string of three has to fail for all three to extinguish. I suggest using a small regulator like this one on eBay (item number: 171814039953) set to give 12V (or slightly less) out using a digital multimeter. The boards are small & can be stuck near the Led string with double sided tape. Soldering skills are required for this particular board, but others are doubtless available with screw connectors. Using a regulator will supply a constant 12V to the Led string regardless of fluctuations of the input voltage. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted September 4, 2015 Share Posted September 4, 2015 It seems fairly common for LED ‘strings’ to be quoted as having a 10V-15V voltage tolerance (example here) http://www.litewave.co.uk/prod_cat/P_high-power-constant-current-led-strip-1015vdc-with-samsung-leds_318_featured_25.html and the ‘smart’ battery-chargers fitted to many modern motorhomes will produce a voltage in excess of 14V. Link to comment Share on other sites More sharing options...
mgnbuk Posted September 7, 2015 Share Posted September 7, 2015 Derek Uzzell - 2015-09-04 7:18 AM It seems fairly common for LED ‘strings’ to be quoted as having a 10V-15V voltage tolerance ...... .........and the ‘smart’ battery-chargers fitted to many modern motorhomes will produce a voltage in excess of 14V. The item you linked to does suggest regulation "on board" to deal with varying input voltages, Derek., though there are no close-ups of the actual Led string to see what extra components are fitted - it would be a bit more than the "transistor & resistor" mentioned, I think. The items linked to by the OP are described as "12V input" & the close-ups show the "3 Leds & a resistor " layout that I have limited experience of. I suggest that this type is optimised for the stated input volatge only & would benefit from an external regulator to maximise the Led life. As you rightly say, the on-board charger raises the nominal 12V to well over 14V for efficient battery charging - a 12V rated Led will not enjoy such an overvoltage for very long. It would be of interest if the OP could keep us posted as to how the replacement string performs (and lasts). Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.