this is what i have, when i get the low battery message.

$ lshal | grep bat
battery.charge_level.capacity_state = 'low' (string)
battery.charge_level.current = 1 (0x1) (int)
battery.charge_level.design = 8 (0x8) (int)
battery.charge_level.last_full = 8 (0x8) (int)
battery.charge_level.percentage = 0 (0x0) (int)
battery.charge_level.unit = 'bars' (string)
battery.is_rechargeable = true (bool)
battery.present = true (bool)
battery.rechargeable.is_charging = false (bool)
battery.rechargeable.is_discharging = true (bool)
battery.remaining_time = 0 (0x0) (int)
battery.remaining_time.calculate_per_time = false (bool)
battery.reporting.current = 5 (0x5) (int)
battery.reporting.design = 1259 (0x4eb) (int)
battery.reporting.last_full = 1222 (0x4c6) (int)
battery.reporting.unit = 'mAh' (string)
battery.type = 'pda' (string)
battery.voltage.current = 3473 (0xd91) (int)
battery.voltage.design = 4200 (0x1068) (int)
battery.voltage.unit = 'mV' (string)
info.capabilities = {'battery'} (string list)
info.category = 'battery' (string)
~ $