Can I Charge A 3.7V Battery Pack With 5V Charger?
Your daily used Power Bank is equipped with a 3.7V cell, but the charger hast a 5V output, will you consider, if is safe to charge a 3.7V battery with a 5V charger?
“My charger port is broke and I want to charge the battery pack, I need to know if a 5v charger will kill the 3.7v power bank?” A guy asked this question but didn’t get a very good answer, so he planned to buy an original charger.
As we all know, if we use a 5V charger to charge a 3.7V cell, it will make the cell to heat and dangerous. But in fact you DON’T need a 3.7V charger.
Because you don’t charge the cell directly, you have a power bank, which has not only battery cell but also PCB and other electronic components to increase 3.7V to 5V.
Voltage increases the amperage into the battery to recharge it. Problem is, without an automatic circuit to reduce the voltage back down to the battery rated voltage within a short time limit, the battery will continue to overcharge, either damaging the battery so that it doesn’t work or, worse, rupturing the battery which can cause additional damage or injury to surrounding items.
So you can charge your 3.7V battery pack with the 5V charger, but be careful, choose one with the automatic circuit, just like the EasyAcc Power Bank. It is equipped with multi-protection, just like over voltage protection, short circuit protection and so on.
The above mentioned idea seems good for any 3.3V microcontrollers, but if you want to operate some 5V devices within the 3.3V circuit (or you are using a 5V microcontroller), powering the system from the 3.7V lithium-ion battery pack demands a suitable dc-dc voltage booster circuit to convert the existing 3.3V to 5V dc level. Described here is an economical yet efficient solution for this problem. The circuit in picture is nothing but an ultra-simple boost converter realized using the popular 8-pin chip MC34063A.