I'm really hooked on the latest rechargeable lithium ion keychain lights such as the Fenix UC02 or the Helius Sigma VI. There are also models from MecArmy, Convey and Wuben among others. They are all somewhat similar sized (around 1.7" length, 0.6" diameter), output around 130 lumens of light (on high) and use either a 10180 or 10150 rechargeable Lithium Ion battery. Most of the these flashlights incorporate an internal charging circuit – so you merely plug in a Micro-USB cable from a typical cell phone charger – and the cell is recharged in under 1 hour.
I have a number of these lights and found their general performance quite good – but have had issue with the internal battery charger not doing a great job (often didn't charge the cell fully). There isn't much space to put high-tech charging circuitry into the flashlight, so there are obviously compromises. I looked for a suitable external charger and was really surprised there aren't many out there that can charge these 10180 or 10150 lithium cells (primarily because the typical Lithium Ion chargers output TOO MUCH current). From the 10180/10150 battery data I can find, the charging current should be around 100mA max, with a 50mA charge current most likely giving better long term life.
Most all common Lithium Ion cable chargers operate at 500mA or 1000mA charge currents (10x the current that you want).
Fortunately – I found you can modify the LiitoKala Model Lii-202 charger to output 50mA or 100mA (instead of it's standard 500mA and 1A modes). The LiitoKala Lii-202 charger is fairly easy to find and pretty in-expensive (I got mine for around $11 on Amazon: https://www.amazon.com/dp/B0742CNDC8/?tag=cpf0b6-20 ) It's a reliable charger that can charge two cells concurrently and automatically determines the battery chemistry voltage along with decreasing current to trickle once you've reached full charge.
NOTE: You will be modifying the charger – voiding any warranty. These changes worked for my unit, but I make no guarantee that it will work for all Lii-202 charger models. If you aren't familiar with soldering/de-soldering small components – I advise not proceeding any further.
I have no affiliation with LiitoKala or any charger or flashlight manufacturer.
You will need the following items:
· LiitoKala Lii-202 Battery Charger
· 0.62 ohm size 1206 surface mount resistor (Qty 2) Available on DigiKey: https://www.digikey.com/product-det...e-product/RLP73K2BR62JTD/A109861CT-ND/4032627
· Tools: Small Philips screwdriver, Soldering Iron, Solder
Here are the general modification steps:
1. Unpack the Lii-202 charger and remove the 6 Philips screws securing the base (figure)
2. Remove the base and pull out the Printed Circuit board. You will find two small resistors marked "R10" and "R20" close to the Positive Battery charging connectors (see fig).
3. Using a soldering iron, remove the existing R10 and R20 resistors and replace with 0.62 ohm 1206 size surface mount resistors.
NOTE: The original R10 & R20 resistors are 0.050ohm (which provide 500mA and 1000mA charge currents). Converting to 50mA and 100mA charge should require a 0.50 ohm resistor – but in practice I found that gave a little too much current so settled on the 0.62 ohm value to stay closer to 50/100mA.
4. Once the resistors are in place – replace the printed circuit board and secure the base with the 6 screws previously removed.
All Done. The charger will now charge at 50mA or 100mA rates – depending on the selected mode (0.5A mode is now 50mA and 1A mode is 100mA – see figures). You will need to add a spacer to accommodate these short 10180/10150 batteries. I've use a large diameter metal screw with good success – but any suitable metal spacer should suffice.
See charging measurements below on a 10180 battery (the Multimeter probes complete the circuit and measure charge current):
Hope this information comes in handy.
I have a number of these lights and found their general performance quite good – but have had issue with the internal battery charger not doing a great job (often didn't charge the cell fully). There isn't much space to put high-tech charging circuitry into the flashlight, so there are obviously compromises. I looked for a suitable external charger and was really surprised there aren't many out there that can charge these 10180 or 10150 lithium cells (primarily because the typical Lithium Ion chargers output TOO MUCH current). From the 10180/10150 battery data I can find, the charging current should be around 100mA max, with a 50mA charge current most likely giving better long term life.
Most all common Lithium Ion cable chargers operate at 500mA or 1000mA charge currents (10x the current that you want).
Fortunately – I found you can modify the LiitoKala Model Lii-202 charger to output 50mA or 100mA (instead of it's standard 500mA and 1A modes). The LiitoKala Lii-202 charger is fairly easy to find and pretty in-expensive (I got mine for around $11 on Amazon: https://www.amazon.com/dp/B0742CNDC8/?tag=cpf0b6-20 ) It's a reliable charger that can charge two cells concurrently and automatically determines the battery chemistry voltage along with decreasing current to trickle once you've reached full charge.
NOTE: You will be modifying the charger – voiding any warranty. These changes worked for my unit, but I make no guarantee that it will work for all Lii-202 charger models. If you aren't familiar with soldering/de-soldering small components – I advise not proceeding any further.
I have no affiliation with LiitoKala or any charger or flashlight manufacturer.
You will need the following items:
· LiitoKala Lii-202 Battery Charger
· 0.62 ohm size 1206 surface mount resistor (Qty 2) Available on DigiKey: https://www.digikey.com/product-det...e-product/RLP73K2BR62JTD/A109861CT-ND/4032627
· Tools: Small Philips screwdriver, Soldering Iron, Solder
Here are the general modification steps:
1. Unpack the Lii-202 charger and remove the 6 Philips screws securing the base (figure)
2. Remove the base and pull out the Printed Circuit board. You will find two small resistors marked "R10" and "R20" close to the Positive Battery charging connectors (see fig).
3. Using a soldering iron, remove the existing R10 and R20 resistors and replace with 0.62 ohm 1206 size surface mount resistors.
NOTE: The original R10 & R20 resistors are 0.050ohm (which provide 500mA and 1000mA charge currents). Converting to 50mA and 100mA charge should require a 0.50 ohm resistor – but in practice I found that gave a little too much current so settled on the 0.62 ohm value to stay closer to 50/100mA.
4. Once the resistors are in place – replace the printed circuit board and secure the base with the 6 screws previously removed.
All Done. The charger will now charge at 50mA or 100mA rates – depending on the selected mode (0.5A mode is now 50mA and 1A mode is 100mA – see figures). You will need to add a spacer to accommodate these short 10180/10150 batteries. I've use a large diameter metal screw with good success – but any suitable metal spacer should suffice.
See charging measurements below on a 10180 battery (the Multimeter probes complete the circuit and measure charge current):
Hope this information comes in handy.