I have a battery pack with an input: D.C. 5V, 2 Amps. I have a tablet-charger with an output: 5.1V, 2.1 A. Can that little difference in Volts and Ampere cause harm to the battery over time? should I look for a 5V/2A charger, or can I use the one I have?Detailed info about the battery and charger:Battery:3.7 V 10 000 mAh/37.0 WhInput: D.C. 5V, 2Aoutput: D.C. 5V, 2.1A + 1 A (two outputs) Charger:input: 100-240V - 0.45A, 50-60Hzoutput: 5.1V, 2.1A
TABLET CHARGER CAN BE USED AS THE REPLACEMENT.
If the battery pack is lithium-ion, it MUST be charged according to the manufacturer's recommendations to minimize the danger of fire. This requires circuitry that shuts off the charge current if the battery reaches an unsafe temperature, and it MUST terminate charging immediately when the battery is fully charged. If it is NiCd or NiMH, charge it at 0.1 c (10% of its Ah rating) for 14 to 18 hours.
That charger is entirely suitable. The 2.1A is the maximum it can deliver if necessary, but it does not force the battery to take it all. The battery pack has charging circuitry which requires a maximum of 5V, but draws only as much current as it needs.
