Battery for servo.

Hello everyone, I have a problem that has been bothering me for a long time and that’s it:
I have 3 LW-20mg servos with these features:

Operating voltage: 4.8V ~ 6.6V DC
Running current(at no load) 6.6V - 500mA
Stall torque (at locked) 20 Kg-cm
Stall current (at locked) 2710 mA
Idle current(at stopped) 5 mA

On the servo is written LiFe, I think it means Lithium-Iron.

Given the cost of modeling batteries that cost an eye of the head if I bought a normal 6V 4Ah motorcycle battery would be okay anyway?
Then I would like to know if it is better to have a battery for each servo or a battery for all 3 is enough?
Thank you
chip

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You can run those 3 servos together on any battery that can supply an appropriate voltage and enough current. SLA batteries will work as will 5 cell 6V NiMH rechargeables as well as LiFe (which I have never found to be particularly expensive).

Steve

A fully charged motorbike lead acid is about 6.6v and should have ample power to power all your servos . You could get a four cell NiMh pack fairly cheaply which would be fine / better