For projects requiring a bit more juice, the mass production of those small rectangular lithium ion batteries for cell phones, cameras and other electronics are extremely useful — the problem is, how do you mount them, short of soldering the terminals in place? With a bit of perfboard of course!
[Jason] came up with this idea when he was trying to figure out a way to mount small lithium cells for a battery fuel gauge for another one of his projects. He found if you use good quality perfboard you can use a 90 degree male pin header to contact the terminals, and a strip of female pin header as a kind of battery stop at the other end. This allows you to very snugly squeeze the battery in place — you may need to adjust the length of the male pins though in order to fine tune the fit!
Now you can add a nice wire terminal, solder up the connections, and there you have it, an easy to make, extremely useful battery holder!
Eh? Ok?
Just solder to the damn thing?
The plastic would start melting. You could damage the cell. You might want to re-charge with an external charger. I like this solution.
One could use a low melting solder. But if possible one should always try to make batteries replaceable IMHO.
One?? I think we all could.!!
I wrote a comment yesterday suggesting pogo pins but was lost somewhere, anyway you can solder to those batteries but you have to be very fast and accurate which for most people often translates into bad solder joints. If I had to solder the battery I would use a short wire, say 10-15 cm, paired with a standard JST connector like the ones they already use with lipo cells.
or just use LiPos for RC planes. they already have cables and connectors in place. Just plug it in and you’re done
In addition to Charlie’s comment, the primary reasons for me doing this is to have a removable, *low-resistance* connection to the battery. While soldering would achieve a low-resistance connection, it is not removable and risks damage to the battery pack.
I agree, I have a camera that uses this exact cell. The external charger is convenient, fast, and cheap (I lost one, had to replace it). I have a couple of cells for my camera and with this great idea I just might buy a couple more.
I like it, plus this way you can have dozens of the same battery and swap them out.
Next challenge is to make it take a variety of battery sizes. Something at the female header end to allow a pair of screws to give you a couple of cm of adjustment?
You don’t use Li-Ion cells as removable.
They sitt in place and recharged until replaced.
Not necessarily. While many applications do use a non-removable (embedded) pack, that doesn’t mean you can’t reuse a Li-ion battery pack in another device…
Maybe “you” don’t personally use them as removable, but the millions of cellphone and digital camera users that can only go so far on a single charge may beg to differ.
Seriously, what are you even doing on this website?
To bash nice projects, obviously.
And yeah I totally agree with you with the battery packs being removable. I wish most devices have them easily removable/replaceable as I use many portable devices. Most requires a screw driver for servicing.
That’d be handy in my cordelss electric tools, having them out of comission while they charge.
janostman, do you design smartphones by any chance?
Does anyone know of a good all-in-one interface module for these types of cells?
I’ve seen chargers and charge level monitors and current sensors and DC/DC converters, but it would be very nice to have them all on one board, so one can have the full function of the battery with a minimum of fuss. I’ve looked at sparkfun, adafruit, pololu, futurlec, seeed, etc. and nobody seems to have the whole package.
I like that, looks compact and functional. I have been planning to do something like that with pogo pins. Not as cheap as the headers but I thought having the spring action would be worth it but seeing how I haven’t put it into use this technique is probably better.
Pogopins or other spring connectors would be much better, as the plain pinheader can scratch the surface of the battery connector and does not give any space to movement. Battery connectors itself aren’t the big problem, more often difficulty is how to get the battery to stay in place and be still removable.
While more expensive one can still find good prices on ebay and other places, 100 pins for ~$10 isn’t that bad.
You don’t even need pogo pins here, you could use those springy safety pins. then use the “latch” of the pin as the header and cut off the pointed one.
Instead of pogo pins, remove the battery contacts from an old phone.
you guys are overkill and complicated.
with $5 (probably less than a perfboard and headers cost nowadays thanks to all the hobby electronic stores) you can get a lot of a dozen dead nokia phones off ebay that uses those batteries.
break them open, use the back. now you have a battery compartment with spring loaded gold plated connectors for the batteries. and a cover.
you can even probably salvage the charging circuity so you have charge in place.
Of course, but where’s the fun in that? ;)
The reason I built these holders this way is because I wanted to create a Li-ion battery holder out of common parts like pin headers and perfboard. Although one could definitely just buy the spring terminal block to hook up to the battery, but almost any electronics hobbyist would already have pin headers on hand to build this.
You don’t even need the stop on the other end. Use two rubber bands. One around the short side to hold it tight against the pref board, and the Other to press it against the contacts. Velcro Cable Ties work too.
+1 for rubber bands – nice and simple
A way to keep it “springy” against the pins would be using a small piece of rubber or vinyl tubing between the end stop header and the battery
I posted a comment directly on his blog site (which hasn’t yet gone through moderation, it appears) to suggest the use of pogo-pins. They are sold at Adafruit and Sparkfun, so they are easy enough to find, though they are kinda expensive. The only issue I can think of involving pogo-pins would be figuring out how to mount them parallel to the board… maybe finding a way to solder another piece of perfboard at a 90 degree angle to the main portion of board to which to attach the pogo-pins.
If You have a 3D-Printer, my friend made this: http://www.thingiverse.com/thing:367385
I was wondering if anybody had done such a thing with laptop computer batteries ?
There are many connectors and it is tricky is to know what connection is what.
Any clue any body ??
“+” and “-” are usually outer pins. Inner pins are for communication and thermistor.
I’ve never seen fixed contacts for battery in cameras, phones, players and other Li-ion powered stuff. They are always spring loaded pins or flexible gold plated contacts. I guess there is good reason for that since that type of connection is more expensive than just using fixed header pins.
Such spring loaded contacts are usually good for hundreds (or thousands) of insertion cycles. And will maintain good contact even if there is motion (phones, robots, etc).
Still, the simple method described here should work well enough for most projects.
If you want to increase reliability/longevity a bit, from what I’ve read, you should use a right angle header with pin plating that matches the type used on the battery contacts. For example, the battery in the picture appears to have gold plating; but some of mine have tin. And I wouldn’t cut the header pins to adjust fit as suggested, as that removes all protective plating – whether tin or gold – and will lead to more rapid oxidation. Instead I’d use a compliant material on the other side, velcro straps, or whatnot as others have suggested.
He should have used longer pin headers, bent the pins in a V shape (instead of keeping them straight) and have the bottom of the V touching the pads on the battery so that the battery could just be pressed down onto the holder and the connection would be solid as they’d be pushing relatively hard against the pads on the battery (much like the typical spring loaded pins currently used in cell phones and cameras)… Otherwise, excellent idea!
Why does no one make a 3 terminal battery holder for these types of batteries? Someone please make schematics for a holder like this for a 3d printer and email them to me please.