acpiconf shows 2 batteries on a laptop?

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This is on Lenovo x240, with original battery:

$ acpiconf -i0
Design capacity:        23200 mWh
Last full capacity:     17740 mWh
Technology:             secondary (rechargeable)
Design voltage:         11100 mV
Capacity (warn):        887 mWh
Capacity (low):         200 mWh
Low/warn granularity:   1 mWh
Warn/full granularity:  1 mWh
Model number:           45N1773
Serial number:          15895
Type:                   LION
OEM info:               SANYO
State:                  high
Remaining capacity:     96%
Remaining time:         1:49
Present rate:           0 mW
Present voltage:        12050 mV

$ acpiconf -i1
Design capacity:        23480 mWh
Last full capacity:     21520 mWh
Technology:             secondary (rechargeable)
Design voltage:         11400 mV
Capacity (warn):        1076 mWh
Capacity (low):         200 mWh
Low/warn granularity:   1 mWh
Warn/full granularity:  1 mWh
Model number:           45N1127
Serial number:            116
Type:                   LION
OEM info:               LGC
State:                  discharging
Remaining capacity:     27%
Remaining time:         0:38
Present rate:           9312 mW
Present voltage:        10829 mV
$ 

Do I really have 2 batteries?
Is this expected?
Only battery 1 seems be charging and
discharging, not 0.

I found this out by accident - acpiconf -i0
was showing full battery, yet the laptop
was switching itself off.

Anton