Battery Powered LED Christmas Tree Lights

[Bazz339]

Yes I know search engines are my friend and I have searched and come up with some options incuding these but can anyone recommend from experience a decent set,

maybe a bit more pro and ideally reachargeable.

 

 

The village christmas tree sits on a crescent of grass in front of my house. There is no mains power available (At least without running a cable across a small road which apart from the liability/legal aspect I would be quite happy to do) A couple of people have looked after it but one has died.

They originally used a 12V battery and latterly some sets powered by maybe 3 AA batteries each. There could really do with being more and brghter, I have been asked in a tangential way to have some input.

The set I have linked to used D cells with a timer which will obviously last longer but are there off the shelf rechargeable pro-ish sets? Ideally I would like 30M (Or more) and would probably use a couple of sets.

It is well within my ability to make something but it is bit late now. Mind you, it is probably a bit late to buy something as well but maybe for next year.

 

T.I.A. Bazz

Edited December 5, 2020 by Bazz339

[sandall]

No idea whether they have what you're after, but Lights4Fun do a huge range of "festive" stuff.

[adam2]

I have obtained acceptable results from cheap battery operated LED Christmas lights. For most applications I would avoid the ones with a timer. These timers are NOT ADJUSTABLE at least none that I have seen are. They run for 6 hours after the batteries are inserted and then go out for 18 hours, and repeat each day. 6 hours is not in my view sufficient.

 

The AA cells dont last long. Rechargeable cells dont work well as the voltage is lower. The run time maybe greatly extended by use of D cells instead. One option is to simply discard the included holder for 3 cells each AA and to fit instead a replacement holder for 3 cells each D size. If doing this, note that there will be a current limiting resistor (usually in the battery box) It is VITAL that this be retained in the circuit.

Keet the battery holder dry or it will rapidly corrode, aided no doubt by leakage currents.

Alternatively, solder wires to the three D cells, still try to keep them dry.

Two sets of D cells will run the lights from early December until twelth night. This is simple and affordable if only one or two sets of lights are needed. No accuracy can be claimed WRT to run times because the lights slowly get dimmer and it is a value judgement as to how dim is acceptable before new batteries are needed. Two weeks per set of good qaulity alkaline D cells is a fair estimate.

 

If several sets of lights are required, battery replacement becomes tedious and expensive.

An alternative approach is to discard the battery holders for the AA cells, and to connect three similar sets of lights in series. TAKE CARE TO RETAIN ALL THREE OF THE CURRENT LIMITING RESISTORS IN CIRCUIT. Three sets in series may be worked from a 12 volt lead acid battery. Such batteries can deliver dangerous currents and a small fuse close to the battery is prudent.

With six sets of lights (two series strings of three) a 7 amp/hour battery will last some days, and a vehicle battery a week or two. An old but somewhat serviceable deep cycle caravan battery is ideal. Think twice about about a new battery due to cost and risk of theft.

[Jivemaster]

What happened to the old lights, and where are they? Can you get more of the same?

[sunray]

A lot of my mains Christmas lights use a 24V transformer, when I've used this sort of stuff for events I've often used car 2 batteries rather than trailing mains cables.

[adam2]

Some types of LED lights do indeed use 24 volts from a transfomer, however this might be 24 volts AC in which case the lights wont work properly or at all, on DC.

[sunray]

Some types of LED lights do indeed use 24 volts from a transfomer, however this might be 24 volts AC in which case the lights wont work properly or at all, on DC.

I'm not trying to say they are all the same but so far I've found they are series circuits of incandescent bulbs or LED's with a series resistor.

 

 

To date I've encountered 2 issues: 1) polarity which is easily sorted.2) The sequencers on some sets sense the ac as a clock pulse but running them on continuous has not been a problem.

 

Several years ago I helped equip a 'Santas Sleigh' car trailer with crazy amounts of LED fairy lights, miles of the stuff, multiple layers wrapped round anything that could be wrapped round amounted to 12A @ 24V spread across 2 pairs of batteries [6A per pair], deliberately built as 2 totally different sets for reliability and day/night use. Ran for 12 hours without a hint of trouble.

I can't say all 24Vsets will run on dc as I haven't tried them all.

 

 

Mains voltage strings of LEDs are a different issue, quite often 4 channels of sequencers are run on 2 circuits incorporating 2 colours of LEDs and reversing polarity changes colour or ac shows both colours.