Introduction: Convert AA Battery/Batteries Devices to Lipo ! QUICK & DIRTY Version 1 Lol

About: Always trying to help someone, though my own skills are limited, i always hope i can help where possible :) . If we all get roughly under 100 years to live a Lifetime, if we are lucky to reach that far, then i…

With today's Power Sources pretty much moving away from the usual Ni-Mh and Alkaline batteries, Lipo are taking over !!

Plus, i really HATE the power given by the Double-A ( AA ) and especially the Triple-A ( AAA ) batteries (dont even get me started on the useless 9v battery lol)

Okay so.. i have a headlamp, it takes 3 AA batteries, as shown in the pics above, it lasts for just over an hour but takes 6-8 hours to recharge using the Manufacturer's own branded Charger, in this case, the Energiser brand of Rechargeable Batteries...

I Solder with a standard soldering iron but i solder SMD components so as they are extremely tiny(like 3.2mm x 1.6xx !!) i need ALOT of light.

Also, i need batteries that'll last longer, and take less time to charge, and so.... I'm now on a mission to convert EVERY device i have to Lipo LOL

At this moment in time, i cant walk, so im stuck in a stationary place for a great many hours, so i have most things at arms reach, although i love making my own PCB's, i cant just yet, so i used what i had laying around, literally at arms reach lol

Literally desperate for power, i used a type of Veroboard that is a "Pad-Per-Hole" type, im not really sure what else to call it, its NOT stripboard as it doesnt have "Strips" of copper lanes, rather it has each individual hole and a copper round (Via) circle around the hold to solder to. see pics and youll see what i mean :)

Step 1: Removing Ni-MH Capability & Cutting Veroboard

Please kindly Note;

As im in high amounts of pain from an ailment, im heavily sedated on pain killers so this was a VERY VERY VERY QUICK & DIRTY HACK to get this battery conversion done lol.

First step is to remove the AA Battery compartment, luckily for this instance, only 4 screws held down the compartment that holds the 3 x AA batteries..

Desoldering the Positive & Negative wires from the AA Compartment free's it from the housing.

Next, As you can see from the Photo's, i didnt have a Ruler lol, so most Veroboard pieces were just "Guesstimated" to fit the Headlamp housing lol

Hand-breaking the veroboard and then i had a pretty useless and blunt file that i used to file down the pieces of veroboard.

The design

Its a really simple design, a piece of veroboard to lay 2 batteries onto, which will have an end-stop (& Front-Stop which will be reinforced as it'll hold the Pogo Pins) and what i also just stumbled across looking for other stuff, lol, was POGO - PINS !

POGO PINS - But the ones i used were Flat-Round Heads - BE CAREFUL of which ones you buy because i bought a large pack of very sharp ones by accident and not looking properly at the picture

Pogo-Pins are spring loaded pins that can be soldered into your circuits and act as battery or contact points for whatever you need !

I opted to use these Sony Ericsson BST-38 type batteries, as i have like, 10+ laying around collecting dust, so thought id make use of them, see picture.

I also opted to use two batteries in parallel but using just one recharge-PCB to charge them up, this is because ive already opened up these types of batteries before (SEE DISCLAIMED RIGHT NOW !!!)

So i know these ones that i have all have the protection PCB's inside them PLUS there is a protection circuit inside the IC that charges these Lipo batteries too, which alerts me when they are fully charged, so im not worried about any charging/overloading problems.


Opening LIPO batteries is DANGEROUS - i bear no responsibility for your own actions, read this as information only unless you KNOW WHAT YOU ARE DOING.

Same goes for Charging/Discharging Lipo Batteries, KNOW WHAT YOUR DOING or DONT DARE ATTEMPT THIS...


So i soldered a back-stop to the base-plate as a starting guide, then measured roughly using the batteries themselves where they will sit and marked with a permanent marker (the veroboard pieces will be cleaned with Nail-Varnish Remover, then polished with Brasso just before soldering so fingerprints, tarnish, dust etc isnt a worry at this stage)

For the Pogo pins, id need 4 of them, two for Battery 1 and two for battery 2..

Plus id need 2 pieces of veroboard - one as a front-stop of the base plate, one to make sure the pogo pins are structurally solid after soldering (reinforced), because even small to medium and large-ish blobs of solder are pretty weak and very malleable (soft) so the pins require some support, i thought...

The pics show in sequence how it all came together, see pics

The Charging PCB, Sony Ericsson Batteries, Pogo Pins and Veroboard i had bought from Ebay, click on the links to see examples, the whole setup cost me around £3-4 GBP/$4-5 USD but as i had everything laying around, it didnt cost me anything.

All in all, a very cheap upgrade & All in 1 step as the pics were taken step by step so you can use this as a photo-guide to use for informative information purposes only :)


Added wire diagram, showing how ive wired it up

- Looking down on it, the left side Pogo Pins are soldered together which form the POSITIVE Rails

- The RIght two Pogo Pins also soldered together to form the NEGATIVE Rails.

- A Wire from each set of pins wired to the BATT Positive & Negative PADS on the USB Lipo Charger PCB Board

Tinker AT YOUR OWN RISK - this should be done using ADULT SUPERVISION providing said Adult knows what they are doing !!!

Step 2: Items to Source

Just 4 Easy to source items; (All Prices in £, Online Conversion tool HERE for your Currency)

BST-38 Siny Ericsson Battery; 1.63

Charging PCB 0.99

Pogo Pins 1.78 ( for 100 pins )

Perfboard 0.99 (for 5 pieces of 50mm x 70mm boards)

Total = £5.39 to buy everything - BUT for TWO of the items, the PerfboardandPogo Pins, you will be able to create & Make LOADS more of these Battery conversion units !!

As for the Charging PCB and Battery = Just £2.62 Each !

So to make your first battery conversion HACK it'll cost you £5.39 but for your second, third, & forth it'll cost just £2.62 EACH !

Thats guessing it'll use one of these 50mm x 70mm pieces of perfboard each HACK, and the one of the peices of perfboard to use to make the front, Back-stops and reinforcement-stops, this is a very pocket-friendly HACK to get involved in :)

Happy Hacking !


The Headlamp has 4 Light Modes, as shown in the pics, Low, Medium, High & Flash, but for these tests i conducted on the High light settings.

All i did was use a stopwatch to time it how long it took for the Headlamp to go to a DIM state or when i could stare into the LED's without hurting my eyes, i dont have an LED Brightness tester, maybe thatll be another instructable in the future lol


Running on 3 x AA Batteries:

Time to Dimness: 1 hour 48 minutes

Charge Time; 6.5 hours

Using Energiser Brand Batteries

Running on two Sony Ericsson BST-38 Batteries;

Time to Dimness: 3 hour 41 minutes
Charge Time; 2 hour 6 minutes


So ive more than doubled the working time of the headlamp and reduced the charging time too, but as i have over 10 of these Sony Ericsson batteries, i'll just keep them ALL charged and quickly swap them out to continue soldering or working on whatever i need the headlamp for lol !

Plus when i get started soldering, im usually soldering for like 3-6 hours so having these batteries charged up and ready to swap out at an instant will be of great help.


Just charged up 12 of these Sony Ericsson Batteries using the Head-Lamp's newly hacked charger, tested each battery with a multi-meter and they all show they are from 4.10 volts to 4.12 volts..

THEN Charged the already charged batteries using a USB charger that specifically charges these type of cell phone batteries and they charged for about 10-20 minutes extra until they all reached around 4.20 volts to 4.25 volts..

So... Conclusion 2;

The protection circuitry inside the Charging IC on the Head-lamp's hacked charger stops charging when the batteries are around 4.13 volts - OR/AND - the protection circuitry inside the batteries themselves also stop the charging so theres clearly over-volt and under-volt protection here. :)



The ones with the holograms i buy but they come from China so no doubt there are fakes lol

Do i really care if they are fakes ?

hell no - they work lol

EDIT; Final Test Results & Thoughts;

Okay by now, ive tested the latest batch of these Sony Ericsson batteries, which HAVE BEEN SITTING IN MY DRAWER since 2012 due to inactivity, on first inspection, they tested for voltage BEFORE charging around 3.83 volts

After a good 2-3 hours on charge, as i haven't used these batteries for YEARS, to my Ultimate Surprise, one PAIR of these Cell Phone batteries lasted SEVEN HOURS !!!! before going too dim to work with..

Also, closer inspection of the charging PCB's IC <--== Click for Photo, it uses a TP4056 <--== Click for Datasheet IC to charge, which doesn't need a MOSFET, sense resistor or blocking diode, click the link of the IC name to see datasheet for more detailed info.

So the IC charges the Lipo batteries to 4.2 volts with a precision of 1.5%, which works out to be 0.063 volts (which is 1.5% of 4.2v)

4.2v minus 0.063v = 4.137

So on my very first & initial testing of the charged batteries in my headlamp, the pair registered at around 4.10v to 4.13v which sounds exactly right for the 1.5% Variance of the charging IC.

All in all now, im pretty happy with the result, have enough batteries charged up for continuous work at high levels of LED lighting where and when i need it most but MOST IMPORTANTLY;-

NO MEMORY EFFECT FROM LONG TERM STORAGE !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Compared to the Ni-Mh batteries that also have been sitting around since 2012, they have dreadful memory effect by now and they are NOT FAKES as i bought them with their own charger in Energizer Official Packaging and from a high street credible retailer here in the UK..

So original GENUINE Ni-Mh Batteries Vs Chinese Knock-off Sony Ericsson Lipo batteries, used AFTER being dormant for many years, clearly the Lipo ones have out-done the Ni-Mh.

There really isnt any competition comparing Ni-Mh to Lipo, its pretty much a no brainer lol Lipo are just in a league of their own, even though these are totally fakes lol

Watch this space, will be creating a really nice version of this PCB some time real soon, now that the prototype came out so damn well lol :)

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