I'm looking to upgrade the battery in my bike light by switching out the single lithium-ion cell for two smaller ones in parallel. Is this feasible? I've heard mixed things about keeping them balanced, and I'm concerned if I'll need to completely replace the charging board or if there's an easier solution.
3 Answers
Using two cells in parallel is perfectly fine! They’ll actually stay balanced naturally as long as you make sure both cells have the same voltage before linking them up. No extra issues should arise with balancing as long as they’re matched well.
Definitely, going parallel is a good call. Unlike series setups that require tighter balancing, two cells in parallel behave differently. The weaker one tends to pull charge from the stronger one until they're both drained equally. Just keep an eye on their voltages during use!
You're right that while the light is off, the cell with higher voltage can donate a bit of current to its weaker counterpart, which might not be ideal long-term. To avoid potential problems, especially if you’re mixing performance levels, consider adding a diode to each output if you decide to go that route. However, if you're only connecting to a charging board that handles a single battery, it could complicate things.
Yes, I think you're right. It might overload the weaker cell with too much current.
So, if I have to stick with one battery connection for both charging and output, would that mean I shouldn’t even try using two cells?