I have purchased and received this battery from eBay. Upon opening it delivers 3v as oppose to 12v-10v and it has a petty output current. I am going to assume this is because it has not been charged much. I have a dc adapter similar to this and i am wondering if i can plug the adapter into the female plug of the battery to let it charge. Would this work and if so what voltage should i set the adapter to for charging?
closed as off-topic by pipe, Voltage Spike, Marcus Müller, Wesley Lee, Dmitry Grigoryev Mar 30 '17 at 8:55
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – pipe, Voltage Spike, Marcus Müller, Wesley Lee, Dmitry Grigoryev
If your battery delivers only 3V (while being obviously 3-cell battery), it means it is fully discharged and possibly damaged because of overdischarge. It may or may not recover if properly charged.
Before asking questions, you should familiarize yourself with methods of charging Li-Ion batteries. If you do so, you would discover that Li-ion cells must be pre-charged with small current (100-200mA) first until they get to about 3V level (each, meaning ~9V for your battery). Then the charge should go at constant current (0.5C is considered as safe level if battery specifications are nor known). Then, when the battery voltage reaches certain level as defined by details of the particular battery chemistry (4.2V can be a safe assumption, giving 3x4.2=12.6V for your battery), the charge should proceed at constant voltage (12.6V, or 4.2V per cell) until the current drops below 100-200mA. This would conclude the charge cycle.
Now it is up to you to decide if your "suggested method" fits into above description. Keep in mind also that the cells in the battery pack are connected in series, so the voltage on inner cells might be distributed unevenly, causing imbalance, overvoltage, and undercharge. For optimal performance and longevity, batteries must have a more sophisticated, "balanced" charger, with more than two connected wires.