£1 Lithium Ion battery charger


Here’s another custom Li Ion battery charger and holder. Yesterday we ran a post involving a custom battery holder for cell phone batteries, today it’s a holder for a more conventional 18650 type Li Ion batteries.

To make a battery charger, just solder the red and black leads to the BATT+/- terminals on the charger board. I got this PCB on eBay for US $1.58 (£0.98). It can be powered by a mini USB cable and features a TP4056 chip which is a generic version of the LTC4056 Li ion charger chip.

We picked up some UltraFire brand Li Ion batteries in China. Seems like a poor name for a product that does have some reputation for sudden and intense explosions.

Via the comments.

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  1. My experience: Ultrafire is fraud!
    *None* of those cells sold as “new” came anywhere close to the advertised capacity. From a batch of 8 pieces, none came above 900mAh while claiming 4000mAh.
    *All* of them showed welding marks at their contact pads indication torn off soldering/interconnection-tabs. They even were of different makes: some sony, one samsung rest unbranded.
    The obvious explanation is that these are recycled old battery cells stripped from defective laptop-batteries.

    Buy Panasonic/Samsung/Sony/Sanyo-cells. They cost a little more but it’s cheaper than to pay anything for that ultrafire-junk. 2000mAh, 2800mAh are decent values. 3800..4000mAh etc are ridiculous – I *promise* you wouldn’t get more than 2200mAh – and even that’s when you’re lucky and getting a healthy cell!

  2. How much should I pay for a name brand 18650 battery? Ultrafire and other battery names with the word “fire” appear a lot of ebay but the name brand ones cost a lot.

  3. How much? About 5 to 10$ per cell at a decent seller (i.e. not on ebay).
    Do you want a cell with protection (short-circuit protection / current limit, over-(dis)charge-protection etc) or do you want an unprotected?
    And then you need a good charger. The actually are quite cheap to make, however, all the cheap ones at ebay are dangerous crap – they will torture and maybe burn your batteries. Often they are recycled surplus and/or crudely hacked cheap NiCd-Chargers.
    Have a look at message boards that deal with LiIon-batteries and stuff…

  4. I cut the wrapper off of my Ultrafire battery and it is in a casing and the end is crimped. Does anyone know a good way to get into it? Or should I just cut the other end with a hacksaw and push the cells through?

    1. I don’t think the OP is really that bothered about blowing up cells, he made a cell holder entirely from metal! That’s a man that likes to take risks!

  5. The cost estimate is on the high side. I just bought 5 of these TP4056 charger boards for $1.36 on an auction site. :)

  6. oh dear, ‘shakes head in shame’ i’ve just bought a lithium charger off of ebay, £2.69 for charging 18650 batteries,

    so here’s my experience: first off i plugged my li ion battery into it, only to find the leds strangely glowing at both the charger and at the plug, so i put the plug into my 12volt powersupply and the unit lights up brighter, but starts getting hot,

    so being the curious kind of guy i am i decided to see what was in it, this is where i go oh my god i’ve been seriously ripped off, so what did i find?

    well firstly i decided to open the cigarette lighter charger plug, only to find out why it had been getting hot,
    yep it had one cheap resistor in it, a resistor that wasn’t big enough 1.6 ohm no circuitry , next i look and think “what’s that? it hasn’t even got a flamin fuse in”

    so that whetted my appetite for more, so i undo the four screws in the battery holder. now this is where i start to get scared, it is empty, yep guys theirs nothing in the thing, no fuse, no microchip, no circuit what so ever, just an led, what a x#x#x# rip off,

    so after seeing all that i decided to look in my camera’s charger (also off of the bay) and low and behold it actually has a proper looking circuit in it “phew”

    just think of it though, if i’d have left it charging, that cheap resistor could have overheated or the battery could have exploded and set fire to the house or the car

    the moral of the story ? be very careful who you buy from, it may just save your life

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