Changing the previous battery on rechargeable bike lights

Hello! Recently I wanted bike lights for my bike. And I remembered that I
already had rechargeable bike lights that I purchased ten years in the past, that I hadn’t
tried in a very long time. I attempted to recharge them, however after totally charging them,
they solely labored for possibly 5 minutes earlier than they turned off once more.

I don’t know a lot about electronics, however I’ve been interested by whether or not it’s
doable to repair previous electronics for a very long time, and this appeared just like the
excellent restore undertaking as a result of I would simply want to exchange the battery.

So I went to the native queer makerspace the place I’m a member to make use of the soldering
iron and attempt to do it! I don’t know a lot about electronics and this submit does
not comprise any security recommendation as a result of I don’t know a lot about security.
I believe it’s good to do tasks in a neighborhood area the place you will get assist.

step 1: cut it open

The bike mild felt prefer it was manufactured from silicone, so I minimize open the silicone in
a haphazard approach alongside one thing that vaguely appeared like a seam.

I undoubtedly ripped some silicone within the course of and it was fairly messy however I
bought it open and located the circuit board.

I don’t know the mannequin variety of the bike lights however there’s a photograph of them at
the top of the submit.

step 2: remove the screws

There had been some screws attaching issues collectively so I eliminated them so I may
get the circuit board out.

Mostly I attempted to take away as few screws as doable as a result of I used to be fearful about
shedding them or not having the ability to put them again after. I most likely put the screws
in a bag or one thing.

step 3: get the circuit board out

I took out the circuit board. Here’s what it appeared like:

You can see the place the battery is hooked up, I believe it’s left of RI3 and above
Q2.

Here’s what the battery appeared like:

step 4: desolder the battery

I’d by no means desoldered something earlier than, so I discovered
the iFixit guide to desoldering and skim it.
Also I requested my buddies Lee and Lauria for recommendation.

Here had been the steps I ended up following based mostly on the information & the recommendation I bought:

1. Use a desoldering pump to take away many of the solder
2. Once most of it’s gone, form of pull them aside to attempt to separate them
3. Also attempt to keep away from getting the battery too sizzling within the course of by taking
   breaks to let it quiet down. I’m not superb with a soldering iron
   so it took some time.
4. The battery has an attachment that’s welded to the highest.
   For some time I believed I wanted to take away this and it appeared unimaginable, however
   it turned out the substitute battery comes with that half so truly I used to be
   supposed to depart it alone.

step 5: identify the battery

In the image of the battery in Step 3, you may see it says one thing like “3”
and “LI???77”. There’s a bit of steel that I believe is welded or one thing to
the highest of the battery. It appeared unimaginable and likewise possibly not good to attempt to
take away so I wasn’t positive how you can discover out what an “LI????77” was or how you can order
one other one.

I’ve been making an attempt to keep away from utilizing LLMs (although I cannot get into that as a result of
I’m exhausted by LLM discourse and I’m positive you might be too), however I actually had
no thought how to determine what the battery was so I requested an LLM. It gave the
response “LIR2477”, which (once I appeared it up) appeared precisely the identical as my
battery so I figured that was believable.

I might have an interest to be taught non-LLM methods to determine this out although.
There should be a approach. Lauria confirmed me how you can use
DigiKey’s search which was very cool
although DigiKey didn’t have that half.

step 6: buy the battery

I went to AliExpress and ordered:

1. 2 batteries (I had 2 bike lights and I wished to repair them each)
2. some silicone glue to connect issues again collectively

I believe the batteries had been $3 every and the glue was $8.

step 7: solder the new batteries in and glue it back together

The components took possibly 2 weeks to arive, and as soon as they arrived, I went again to the
makerspace and:

• soldered within the new batteries
• put the screws again in. The screws had been very small and exhausting to carry, so at
  this level I dropped some screws on the bottom and couldn’t discover them as a result of
  they had been too small. So I simply used fewer screws and hoped for one of the best.
• used the glue to attempt to put all the things again collectively.
• Make a considerably halfhearted try and clamp the components I used to be gluing collectively

Then after ready some period of time for the glue to dry I took it residence and
waited 24 hours for the glue to remedy.

Also I took the previous batteries to someplace close by that accepts previous batteries.

it works!

The lights work! I’ve used them to bike at evening! I nonetheless haven’t wanted to
recharge them (and tragically I needed to order a brand new Mini USB cable as a result of I bought
rid of all my Mini USB cables, so I’m nonetheless ready for that), so I nonetheless don’t
know for positive how lengthy the lifetime of the brand new battery might be.

Here’s what the sunshine seems to be like after re-gluing.
You can see that I didn’t glue very rigorously. It didn’t actually return
collectively that effectively however I’m hoping it’ll be adequate.

I believed it was actually cool that I used to be ready to do that with extraordinarily minimal
electronics expertise! It value about $20 CAD to purchase the components, and (whether or not or not
the restore holds up, I’ll attempt to replace this submit sooner or later!), it was enjoyable to
attempt to restore one thing and be taught one thing new.