Where to get a battery for a B&M Luxos U

General cycling advice ( NOT technical ! )
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Benethi
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Joined: 6 Jun 2010, 9:50pm

Where to get a battery for a B&M Luxos U

Post by Benethi »

Hi,

I've got a couple of B&M Luxos U dynamo lights. The first was one of the original ones, with the detachable switch - despite the problems that people apparently had with it, mine lasted years.
Eventually though it became increasingly unreliable, I think just because the battery was dead, and I replaced it with one of the new ones with the switch permanently attached...which frankly is a right PITA, but that's another issue. Anyway, the new one didn't last five minutes - I really should have sent it back, but I was busy and not cycling much, and never got round to looking into it, and now two years seem to have passed and I haven't done anything about it.

Anyway, does anyone happen to know where I can get a replacement battery? It's this one:
https://www.aliexpress.com/item/4001084813163.html
however is showing as unavailable here and I can't find it anywhere else.

Cheers.
"Frankly, I’m suspicious of anyone who has a strong opinion on a complicated issue" - Scott Adams
Photos:
Scott's Travels 2010
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Sparky's Travels 2013
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cycleruk
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Location: Lancashire

Re: Where to get a battery for a B&M Luxos U

Post by cycleruk »

Is your Aliexpress link the exact battery for your lights. ?
You'll never know if you don't try it.
rjb
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Re: Where to get a battery for a B&M Luxos U

Post by rjb »

Those packs of batteries are similar to one's often found in cordless phones. They should be widely available. :wink:
If this is for a dynamo light it could just be providing a standlight function. So depending on your skillset it's possible to incorporate a DIY battery backup in your lighting system or even a super capacitor standlight.(no batteries needed).
At the last count:- Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X3, Raleigh 20 stowaway, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840 :D
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andrew_s
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Re: Where to get a battery for a B&M Luxos U

Post by andrew_s »

A Luxos U will use the battery to keep the USB supply to your GPS or whatever going whilst you are at the traffic lights, as well as providing a standlight, or to supply additional USB power if you aren't riding fast enough to keep up with the demand.
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Benethi
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Re: Where to get a battery for a B&M Luxos U

Post by Benethi »

cycleruk wrote: 27 Mar 2023, 1:03pm Is your Aliexpress link the exact battery for your lights. ?
Yes, at least it appears to be identical to the one I've taken out.
rjb wrote: 27 Mar 2023, 1:19pm Those packs of batteries are similar to one's often found in cordless phones. They should be widely available. :wink:
If this is for a dynamo light it could just be providing a standlight function. So depending on your skillset it's possible to incorporate a DIY battery backup in your lighting system or even a super capacitor standlight.(no batteries needed).
My skilllset...just about allows me to operate a light switch (if I concentrate) :wink:
Yeah, standlight plus various other mostly unneeded features. But thanks, I'll see if I can find anything with a similar battery!
"Frankly, I’m suspicious of anyone who has a strong opinion on a complicated issue" - Scott Adams
Photos:
Scott's Travels 2010
Sparky's Travels 2012
Sparky's Travels 2013
:)
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cycleruk
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Re: Where to get a battery for a B&M Luxos U

Post by cycleruk »

These batteries are labelled Li-ion and seem hard to find. It looks like China won't post to the UK.
There are 'Li-Po' ones which are very similar and can be used instead although not as good a cell.
Do a Google on Li-ion versus Li-po to see the differences.
Going on your link there will be 4 cells (2 in each pack) and probably soldered to a circuit board.
So if you want and can find Li-Po cells of a similar 'physical size' they should do the job.
These Lithium cells are used in small radio control models and should be available on the web' or some model suppliers.
Some soldering will be needed. Remove the blue heat shrink covering to measure the size of a cell for a replacement.
The link says 6.4 volts and 100mA. Nominally these cells are 3.7v each ( x2 = 7.4v ) so I presume there is some form of control on the circuit board. If replacement cells are more than 100mA then that's not a problem.
Be careful not to short out the cell leads and get them the right way round when soldering.
You'll never know if you don't try it.
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Benethi
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Re: Where to get a battery for a B&M Luxos U

Post by Benethi »

cycleruk wrote: 29 Mar 2023, 9:58am These batteries are labelled Li-ion and seem hard to find. It looks like China won't post to the UK.
There are 'Li-Po' ones which are very similar and can be used instead although not as good a cell.
Do a Google on Li-ion versus Li-po to see the differences.
Going on your link there will be 4 cells (2 in each pack) and probably soldered to a circuit board.
So if you want and can find Li-Po cells of a similar 'physical size' they should do the job.
These Lithium cells are used in small radio control models and should be available on the web' or some model suppliers.
Some soldering will be needed. Remove the blue heat shrink covering to measure the size of a cell for a replacement.
The link says 6.4 volts and 100mA. Nominally these cells are 3.7v each ( x2 = 7.4v ) so I presume there is some form of control on the circuit board. If replacement cells are more than 100mA then that's not a problem.
Be careful not to short out the cell leads and get them the right way round when soldering.
Thanks for the info! :)
"Frankly, I’m suspicious of anyone who has a strong opinion on a complicated issue" - Scott Adams
Photos:
Scott's Travels 2010
Sparky's Travels 2012
Sparky's Travels 2013
:)
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