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Modifying Tesco 3W Cree lights

amaferangaamaferanga Posts: 6,789
edited December 2009 in Workshop
I've started modifying my Tesco 3W Cree as I'm bored and needed something to do. I've cut down the barrel and soldered wires to the contacts to retain the switch. Now it needs a battery.

I messed about with a 3 x AA battery holder from Maplin, but it's neither waterproof nor particularly robust. A bit of Googling has uncovered various custom battery packs and I'm thinking of getting a couple (one to use and one to carry as a spare). But I'm unsure about what sort of connectors to use and what sort of charger I will need. I don't want to spend a lot of money (I already have a P7 torch which is perfectly good for most of my riding) so need something cheap-ish. I'm also wondering if I'd get away with 4.8V without damaging the light (I read that its 4V max, but also read somewhere about someone who was running it at 4.8V).

So my questions:

1) Where's the best place to get custom battery packs (3 or 4 batteries in one row is what I want with end tags) in shrink wrap? Alternatively, is it easy enough to solder batteries together end-to-end (bearing in mind I can solder, but I'm very much an amateur)?

2) Can I run the light at 4.8V?

3) What sort of cable and connectors should I use?

4) What sort of charger will I need?

Any other general advice would be much appreciated. I'm looking to end up with something that looks decent and not too Heath Robinson.

Thanks.
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Posts

  • rakerake Posts: 3,281
    i have a mild hobby of electronics.im building myself a double 3w led light.a power diode (under a pound from maplins) will drop about 0.7 volts over most of its current range.therefore 4.8v will be 4.1v even with varying current loads unlike a resistor so much more versatile and adaptable without having to be spot on with calculations.just wire it in series to your power lead. a side effect will be if you accidently connect the power reversed the diode will block it. i too am using 4.8v batterys. im using model car battery with 4600ma capacity nimh. maybee ill use two when i have some cash.i think they offer the best value. fast recharge capability. the problem with lithium polymer batteries apart from the cost is that they decay or go off even when not used.they have a shelf life.nimh can be used for 1000+ charges. thats 3years if you charged it every day.no need to be soldering its already shrink wrapped and leaded. they work out at a similar price to tagged batteries as well. then get a delta peak model charger for it. auto turn off when its full so no guessing and damage from over charging. and for the holder i have an old cygo light water bottle battery. all thats inside is a 4.5ah lead acid held in with expanding foam. get a wide mouth water bottle and just pack it in with foam and a rubber gromet for the wire hole out of the top. i think thats answered all your questions. feel free to put some more. oh and if you can tell me what power or current your lights will use il select you a diode from mapplins.
  • amaferangaamaferanga Posts: 6,789
    Thanks for that, really useful. I've found this 4.8V 5000mAh battery which looks like it might do. Can you tell me why there are two sets of wires coming from the battery? And what sort of connector would I need for the wires coming from the light to connect to the battery pack?
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  • rakerake Posts: 3,281
    the small wire is for the radio reciever you get on models. just ignore that.there are a few common types of connector but its most likely a tamiya plug.they will have a suitable charger.
    you can get packs without the servo lead. vapextech they are a top name in rc.
    you want a 1N5400 diode. the maplins order code is QL81C price is 23p.
  • amaferangaamaferanga Posts: 6,789
    Okay so I've found a charger and vapextech have 4.8V 4300mAh packs, but why the diode?
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  • hopper1hopper1 Posts: 4,708
    Look here for custom battery packs.
    Batteries used are 18650's... :wink:
    Start with a budget, finish with a mortgage!
  • rakerake Posts: 3,281
    you said your light is rated 4v. the diode will drop 0.7-0.8v off your 4.8v battery bringing it to the required range..
  • amaferangaamaferanga Posts: 6,789
    hopper1 wrote:
    Look here for custom battery packs.
    Batteries used are 18650's... :wink:

    Are those holders connected parallel or series or are they user configurable? It'd obviously need to be parallel for me. Looks quite interesting though.
    More problems but still living....
  • amaferangaamaferanga Posts: 6,789
    Just order one of these instead after realising the it'd probably end up costing almost as much or a far inferior light.

    3 hours at 900 Lumens or 4.5 hours at 500 Lumens :D:D:D
    More problems but still living....
  • rakerake Posts: 3,281
    they are very good. my home built should be equivalent to that on low about 500lm.but ive built a mega rear light to run off the same battery as the front.3 brightness settings and sos on each front light so many modes of operation. should go 8 hours on 1 light full and 4 hours on 2 full beam including the ****off rear light.cost about £40 with battery and charger. so theres not much margine for cost saving when you add it up.those lithium batterys do look good though.just hope they dont explode or decay too soon. i think the rear are overlooked but thats where you cant see and people come at speed.
  • hopper1hopper1 Posts: 4,708
    amaferanga wrote:
    Just order one of these instead after realising the it'd probably end up costing almost as much or a far inferior light.

    3 hours at 900 Lumens or 4.5 hours at 500 Lumens :D:D:D

    I've ordered two of those, one from BOB the other from Kai, both being shipped Friday.
    I also have two P7's on order, battery charger, spare batteries and updated LED's :shock:
    amaferanga wrote:
    Are those holders connected parallel or series or are they user configurable? It'd obviously need to be parallel for me. Looks quite interesting though.
    I think there in series, so I'll have 4 hours burn time with the P7, instead of 1 hour, when used with the single battery. The battery holder arrived today, very well made. Have to wire them up myself, but no big deal, instructions supplied.
    Start with a budget, finish with a mortgage!
  • amaferangaamaferanga Posts: 6,789
    hopper1 wrote:
    I think there in series, so I'll have 4 hours burn time with the P7, instead of 1 hour, when used with the single battery. The battery holder arrived today, very well made. Have to wire them up myself, but no big deal, instructions supplied.

    You need them in parallel to increase burn time.
    More problems but still living....
  • hopper1hopper1 Posts: 4,708
    amaferanga wrote:
    hopper1 wrote:
    I think there in series, so I'll have 4 hours burn time with the P7, instead of 1 hour, when used with the single battery. The battery holder arrived today, very well made. Have to wire them up myself, but no big deal, instructions supplied.

    You need them in parallel to increase burn time.

    Oops.... :oops:
    They're in parallel, then :wink:
    Start with a budget, finish with a mortgage!
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