[Hummerboss1]

I want to run 4 devices that run on 3 to 3.3 volts (2 aaa, aa, c or d cell batteries). I am going to get a Lithium-ion battery pack that is 3.7 volts with 15.6 aH's. Yes this will make a very long run time since the devices don't use a lot of current. Here is the question, will 3.7 volts harm the devices that only use 3 volts? The battery pack when fully charge is slightly over 4 volts but this is the closest voltage I can find in a high capacity lithium-ion pack. This is all DC by the way as well. If it is too much what can I solder in line to reduce 3.7 volts to 3 volts that could handle 1 to 2 amps of current max without burning up? Thanks very much.

[Stratmando]

Do these devices have any distance to the run? if so, the voltage drop may do that for you?
Low voltage drops fast.

[Hummerboss1]

No, the devices and the entire circuit and setup are all within a square foot.

[Hummerboss1]

I want to run 4 devices that run on 3 to 3.3 volts (2 aaa, aa, c or d cell batteries). I am going to get a Lithium-ion battery pack that is 3.7 volts with 15.6 aH's. Yes this will make a very long run time since the devices don't use a lot of current. Here is the question, will 3.7 volts harm the devices that only use 3 volts? The battery pack when fully charge is slightly over 4 volts but this is the closest voltage I can find in a high capacity lithium-ion pack. This is all DC by the way as well. If it is too much what can I solder in line to reduce 3.7 volts to 3 volts that could handle 1 to 2 amps of current max without burning up? Thanks very much.

[Stratmando]

I would hook hup a meter, power up, check the voltage and power down, you may be closer than you think. A little momentary overvoltage should not hurt. Plus as the pack wears down, the voltage will drop.
You can always use a regulator.