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Replace 12V SLA charger's LED indicator...?

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revans

New Member
Hi there, I've got a 12V SLA charger (12v Junior Battery Fighter 3 Stage 750mAh). I'm putting it in an enclosure with some other electronics and so have stripped off the casing, etc.

However, the charger has a red/green bi-colour LED that I would like to panel mount on the enclosure. Currently, the LED is soldered to the charger's PCB. BUT... while the stock LED is 5mm, while the LED panel mounts I'm using are 3mm.

I was thinking that in place of the stock 5mm LED I'd be able to run some wire to a similar 3mm bi-colour LED. Is there any reason why this shouldn't work? The led I'm looking at using is this one here: LED 3MM DIF BICOL RED/GRN I can post pictures of the circuit if you want.

Thanks for any help.
 
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RODALCO

Well-Known Member
As long the LED current doesn't exceed 20 mA's there is no problem fitting a 3 mmØ LED instead of a 5 mmØ LED.

Ensure that the series resistor is fitted.
 

revans

New Member
Hmm yeah, just remembered I have a multimeter lying around somewhere I could put to good use... I guess if the current and voltage are at pretty standard levels for an led there's no reason why I shouldn't just swap it out.
 

revans

New Member
Well I bought this bi-colour LED: LED 3MM DIF BICOL COM CATH ORG/GRN 4.5/6 - Jaycar Electronics

Now though, I'm wondering how to replace it. Specifically, I'm not sure how to tell which leg on my replacement corresponds to which leg on the original.

Obviously, they both have three leads. Going by this site here: Light Emitting Diodes (LEDs) I can identify the leads on my replacement, however I can't match them to the stock LED as its leads are no longer the original length... I would assume the middle lead is the common cathode, however I can't identify a1 or a2... How can I do this?

EDIT: Also going by the above site, I think what I'm dealing with is technically a tricolour LED
 
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revans

New Member
Success! I ended up removing the stock LED and determining which outside lead produced a green light, and then soldered the green lead for my replacement in the same place. Works a charm... and now I can panel mount my charging indicator... woot...!
 
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