Keysight N9927-90001 User’s Guide                                                            691
Working with the Lithium-Ion Battery
Charging the Battery
Using the External Battery Charger (N9910X–872) 
Figure 32-2 External Battery Charger (N9910X-872)
The external battery charger (N9910X–872), lets you charge a fully depleted 
battery in approximately three hours. It is a two bay, level–3 stand-alone 
battery charger that is compliant with the standard Smart Battery System. The 
two bays are charged sequentially on a first-come, first-served basis, though a 
discharge can be performed in the left bay while the right bay is charging. 
For more information, refer to the Instruction Manual included with the 
external battery charger.
Read the safety information in
 “For the External Battery Charger 
(N9910X-872)” on page 699
.
External Battery Charger LED Charging Status
Green Fully charged
Green flashing Fast charging
Yellow flashing Reconditioning – the accuracy of the 
battery’s internal LED charge gauge 
is being renewed. See 
“Reconditioning Battery” on 
page 692
Yellow/green Battery is reconditioned
Red flashing Error
Yellow Standby