diff --git a/tv/2configs/default.nix b/tv/2configs/default.nix
index 514d313c1..dbf311479 100644
--- a/tv/2configs/default.nix
+++ b/tv/2configs/default.nix
@@ -14,7 +14,7 @@ with import <stockholm/lib>;
       stockholm.file = "/home/tv/stockholm";
       nixpkgs.git = {
         url = https://github.com/NixOS/nixpkgs;
-        ref = "238c7e0dbf73d7f330689cb6ec4b1218526cee4e";
+        ref = "1e1112edc57e93046f35707b874d2a4f3ff321e6";
       };
     } // optionalAttrs host.secure {
       secrets-master.file = "/home/tv/secrets/master";
diff --git a/tv/5pkgs/q/default.nix b/tv/5pkgs/q/default.nix
index 7e2a30c3e..a3a7cd739 100644
--- a/tv/5pkgs/q/default.nix
+++ b/tv/5pkgs/q/default.nix
@@ -84,11 +84,18 @@ let
       eval "$(${pkgs.gnused}/bin/sed -n '
         s/^\([A-Z_]\+=[0-9A-Za-z_-]*\)$/export \1/p
       ' $uevent)"
-      if test "x''${POWER_SUPPLY_CHARGE_NOW-}" = x; then
-        exit # not battery
-      fi
+      case $POWER_SUPPLY_NAME in
+        AC)
+          exit # not battery
+          ;;
+      esac
       exec </dev/null
       exec ${pkgs.gawk}/bin/awk '
+        function die(s) {
+          printf "%s: %s\n", name, s
+          exit 1
+        }
+
         function print_hm(h, m) {
           m = (h - int(h)) * 60
           return sprintf("%dh%dm", h, m)
@@ -115,39 +122,83 @@ let
         }
 
         END {
-          voltage_unit = "V"
-          voltage_now = ENVIRON["POWER_SUPPLY_VOLTAGE_NOW"] / 10^6
-          voltage_min_design = ENVIRON["POWER_SUPPLY_VOLTAGE_MIN_DESIGN"] / 10^6
-
-          current_unit = "A"
-          current_now = ENVIRON["POWER_SUPPLY_CURRENT_NOW"] / 10^6
-
-          power_unit = "W"
-          power_now = current_now * voltage_now
+          name = ENVIRON["POWER_SUPPLY_NAME"]
 
           charge_unit = "Ah"
           charge_now = ENVIRON["POWER_SUPPLY_CHARGE_NOW"] / 10^6
           charge_full = ENVIRON["POWER_SUPPLY_CHARGE_FULL"] / 10^6
-          charge_ratio = charge_now / charge_full
+
+          current_unit = "A"
+          current_now = ENVIRON["POWER_SUPPLY_CURRENT_NOW"] / 10^6
 
           energy_unit = "Wh"
-          energy_full = charge_full * voltage_min_design
+          energy_now = ENVIRON["POWER_SUPPLY_ENERGY_NOW"] / 10^6
+          energy_full = ENVIRON["POWER_SUPPLY_ENERGY_FULL"] / 10^6
 
-          printf "%s %s %d%% %.2f%s/%.2f%s %d%s/%.1f%s %s\n" \
-            , ENVIRON["POWER_SUPPLY_NAME"] \
-            , print_bar(10, charge_ratio) \
-            , charge_ratio * 100 \
-            , charge_now, charge_unit \
-            , current_now, current_unit \
-            , energy_full, energy_unit \
-            , power_now, power_unit \
-            , print_hm(charge_now / current_now)
+          power_unit = "W"
+          power_now = ENVIRON["POWER_SUPPLY_POWER_NOW"] / 10^6
+
+          voltage_unit = "V"
+          voltage_now = ENVIRON["POWER_SUPPLY_VOLTAGE_NOW"] / 10^6
+          voltage_min_design = ENVIRON["POWER_SUPPLY_VOLTAGE_MIN_DESIGN"] / 10^6
+
+          #printf "charge_now: %s\n", charge_now
+          #printf "charge_full: %s\n", charge_full
+          #printf "current_now: %s\n", current_now
+          #printf "energy_now: %s\n", energy_now
+          #printf "energy_full: %s\n", energy_full
+          #printf "energy_full: %s\n", ENVIRON["POWER_SUPPLY_ENERGY_FULL"]
+          #printf "energy_full: %s\n", ENVIRON["POWER_SUPPLY_ENERGY_FULL"] / 10^6
+          #printf "power_now: %s\n", power_now
+          #printf "voltage_now: %s\n", voltage_now
+
+          if (current_now == 0 && voltage_now != 0) {
+            current_now = power_now / voltage_now
+          }
+          if (power_now == 0) {
+            power_now = current_now * voltage_now
+          }
+          if (charge_now == 0 && voltage_min_design != 0) {
+            charge_now = energy_now / voltage_min_design
+          }
+          if (energy_now == 0) {
+            energy_now = charge_now * voltage_min_design
+          }
+          if (charge_full == 0 && voltage_min_design != 0) {
+            charge_full = energy_full / voltage_min_design
+          }
+          if (energy_full == 0) {
+            energy_full = charge_full * voltage_min_design
+          }
+
+          if (charge_now == 0 || charge_full == 0) {
+            die("unknown charge")
+          }
+
+          charge_ratio = charge_now / charge_full
+
+          out = out name
+          out = out sprintf(" %s", print_bar(10, charge_ratio))
+          out = out sprintf(" %d%", charge_ratio * 100)
+          out = out sprintf(" %.2f%s", charge_now, charge_unit)
+          if (current_now != 0) {
+            out = out sprintf("/%.1f%s", current_now, current_unit)
+          }
+          out = out sprintf(" %d%s", energy_full, energy_unit)
+          if (power_now != 0) {
+            out = out sprintf("/%.1f%s", power_now, power_unit)
+          }
+          if (current_now != 0) {
+            out = out sprintf(" %s", print_hm(charge_now / current_now))
+          }
+
+          print out
         }
       '
     '';
   in ''
     for uevent in /sys/class/power_supply/*/uevent; do
-      ${power_supply} "$uevent"
+      ${power_supply} "$uevent" || :
     done
   '';