diff --git a/fhem/CHANGED b/fhem/CHANGED
index 4afa148a0..f799ef809 100644
--- a/fhem/CHANGED
+++ b/fhem/CHANGED
@@ -1,5 +1,6 @@
 # Add changes at the top of the list. Keep it in ASCII, and 80-char wide.
 # Do not insert empty lines here, update check depends on it.
+  - feature: 74_XiaomiBTLESens: add new set command resetBatteryTimestamp
   - bugfix:  93_DbRep: some perl warnings fixed
   - fhem.pl: restoreDir restructured (Forum #85801)
   - added:   88_xs1Bridge: added blacklist function
diff --git a/fhem/FHEM/74_XiaomiBTLESens.pm b/fhem/FHEM/74_XiaomiBTLESens.pm
index c4a34afd1..6d5e37839 100644
--- a/fhem/FHEM/74_XiaomiBTLESens.pm
+++ b/fhem/FHEM/74_XiaomiBTLESens.pm
@@ -39,15 +39,18 @@
 
 package main;
 
+my $missingModul = "";
+
 use strict;
 use warnings;
 use POSIX;
 
-use JSON;
-use Blocking;
+eval "use JSON;1" or $missingModul .= "JSON ";
+eval "use Blocking;1" or $missingModul .= "Blocking ";
+#use Data::Dumper;          only for Debugging
 
 
-my $version = "2.0.9";
+my $version = "2.0.10";
 
 
 
@@ -86,6 +89,7 @@ sub XiaomiBTLESens_ProcessingNotification($@);
 sub XiaomiBTLESens_WriteReadings($$);
 sub XiaomiBTLESens_ProcessingErrors($$);
 sub XiaomiBTLESens_encodeJSON($);
+sub CometBlueBTLE_CmdlinePreventGrepFalsePositive($);
 
 sub XiaomiBTLESens_CallBattery_IsUpdateTimeAgeToOld($$);
 sub XiaomiBTLESens_CallBattery_Timestamp($);
@@ -147,6 +151,7 @@ sub XiaomiBTLESens_Define($$) {
     my @a = split( "[ \t][ \t]*", $def );
     
     return "too few parameters: define <name> XiaomiBTLESens <BTMAC>" if( @a != 3 );
+    return "Cannot define XiaomiBTLESens device. Perl modul ${missingModul}is missing." if ( $missingModul );
     
 
     my $name                                = $a[0];
@@ -162,7 +167,8 @@ sub XiaomiBTLESens_Define($$) {
         
     
     readingsSingleUpdate($hash,"state","initialized", 0);
-    $attr{$name}{room}                      = "XiaomiBTLESens" if( AttrVal($name,'room','none') eq 'none' );
+    #$attr{$name}{room}                      = "XiaomiBTLESens" if( AttrVal($name,'room','none') eq 'none' );
+    CommandAttr(undef,$name . ' room XiaomiBTLESens') if( AttrVal($name,'room','none') eq 'none' );
     
     Log3 $name, 3, "XiaomiBTLESens ($name) - defined with BTMAC $hash->{BTMAC}";
     
@@ -265,7 +271,7 @@ sub XiaomiBTLESens_Notify($$) {
     return if (!$events);
 
 
-    XiaomiBTLESens_stateRequestTimer($hash) if( (grep /^DEFINED.$name$/,@{$events}
+    XiaomiBTLESens_stateRequestTimer($hash) if( (((grep /^DEFINED.$name$/,@{$events}
                                                     or grep /^INITIALIZED$/,@{$events}
                                                     or grep /^MODIFIED.$name$/,@{$events}
                                                     or grep /^DELETEATTR.$name.disable$/,@{$events}
@@ -273,8 +279,9 @@ sub XiaomiBTLESens_Notify($$) {
                                                     or grep /^DELETEATTR.$name.interval$/,@{$events}
                                                     or grep /^DELETEATTR.$name.model$/,@{$events}
                                                     or grep /^ATTR.$name.model.+/,@{$events}
-                                                    or grep /^ATTR.$name.interval.[0-9]+/,@{$events} ) and $init_done and $devname eq 'global' );
-
+                                                    or grep /resetBatteryTimestamp$/,@{$events}
+                                                    or grep /^ATTR.$name.interval.[0-9]+/,@{$events}) and $devname eq 'global')
+                                                    or grep /^resetBatteryTimestamp$/,@{$events}) and $init_done  );
 
     XiaomiBTLESens_CreateParamGatttool($hash,'read',$XiaomiModels{AttrVal($name,'model','')}{devicename}) if( AttrVal($name,'model','thermoHygroSens') eq 'thermoHygroSens' 
                                                                                                                 and $devname eq $name
@@ -349,10 +356,16 @@ sub XiaomiBTLESens_Set($$@) {
 
         my $devicename = join( " ", @args );
         $mod = 'write'; $handle = $XiaomiModels{AttrVal($name,'model','')}{devicename}; $value = XiaomiBTLESens_CreateDevicenameHEX(makeDeviceName($devicename));
+        
+    } elsif( $cmd eq 'resetBatteryTimestamp' ) {
+        return "usage: resetBatteryTimestamp" if( @args != 0 );
+        
+        $hash->{helper}{updateTimeCallBattery}  = 0;
+        return;
     
     } else {
-        my $list = "";
-        $list .= "devicename" if( AttrVal($name,'model','thermoHygroSens') eq 'thermoHygroSens' );
+        my $list = "resetBatteryTimestamp:noArg";
+        $list .= " devicename" if( AttrVal($name,'model','thermoHygroSens') eq 'thermoHygroSens' );
         
         return "Unknown argument $cmd, choose one of $list";
     }
@@ -462,8 +475,11 @@ sub XiaomiBTLESens_ExecGatttool_Run($) {
         while($wait) {
         
             my $grepGatttool;
-            $grepGatttool = qx(ps ax| grep -E \'gatttool -i $hci -b $mac\' | grep -v grep) if($sshHost eq 'none');
-            $grepGatttool = qx(ssh $sshHost 'ps ax| grep -E "gatttool -i $hci -b $mac" | grep -v grep') if($sshHost ne 'none');
+            my $gatttoolCmdlineStaticEscaped = CometBlueBTLE_CmdlinePreventGrepFalsePositive("gatttool -i $hci -b $mac");
+            #$grepGatttool = qx(ps ax| grep -E \'gatttool -i $hci -b $mac\' | grep -v grep) if($sshHost eq 'none');
+            #$grepGatttool = qx(ssh $sshHost 'ps ax| grep -E "gatttool -i $hci -b $mac" | grep -v grep') if($sshHost ne 'none');
+            $grepGatttool = qx(ps ax| grep -E \'$gatttoolCmdlineStaticEscaped\') if($sshHost eq 'none');
+            $grepGatttool = qx(ssh $sshHost 'ps ax| grep -E "$gatttoolCmdlineStaticEscaped"') if($sshHost ne 'none');
 
             if(not $grepGatttool =~ /^\s*$/) {
                 Log3 $name, 3, "XiaomiBTLESens ($name) - ExecGatttool_Run: another gatttool process is running. waiting...";
@@ -639,7 +655,7 @@ sub XiaomiBTLESens_FlowerSensHandle0x38($$) {
     my @dataBatFw   = split(" ",$notification);
 
     $readings{'batteryLevel'}   = hex("0x".$dataBatFw[0]);
-    $readings{'battery'}        = (hex("0x".$dataBatFw[0]) > 20?"ok":"low");
+    $readings{'battery'}        = (hex("0x".$dataBatFw[0]) > 19 ? "ok" : "low");
     $readings{'firmware'}       = ($dataBatFw[2]-30).".".($dataBatFw[4]-30).".".($dataBatFw[6]-30);
         
     $hash->{helper}{CallBattery} = 1;
@@ -690,7 +706,7 @@ sub XiaomiBTLESens_ThermoHygroSensHandle0x18($$) {
     chomp($notification);
         
     $readings{'batteryLevel'}   = hex("0x".$notification);
-    $readings{'battery'}        = (hex("0x".$notification) > 20?"ok":"low");
+    $readings{'battery'}        = (hex("0x".$notification) > 15 ? "ok" : "low");
         
     $hash->{helper}{CallBattery} = 1;
     XiaomiBTLESens_CallBattery_Timestamp($hash);
@@ -876,6 +892,22 @@ sub XiaomiBTLESens_CreateDevicenameHEX($) {
     return $devicenameHex;
 }
 
+sub CometBlueBTLE_CmdlinePreventGrepFalsePositive($) {
+# https://stackoverflow.com/questions/9375711/more-elegant-ps-aux-grep-v-grep
+# Given abysmal (since external-command-based) performance in the first place, we'd better
+# avoid an *additional* grep process plus pipe...
+
+    my $cmdline = shift;
+
+  
+    $cmdline =~ s/(.)(.*)/[$1]$2/;
+    return $cmdline;
+}
+
+
+
+
+
 
 
 
@@ -934,6 +966,7 @@ sub XiaomiBTLESens_CreateDevicenameHEX($) {
   <b>Set</b>
   <ul>
     <li>devicename - set a devicename</li>
+    <li>resetBatteryTimestamp - when the battery was changed</li>
     <br>
   </ul>
   <br><br>
@@ -1019,6 +1052,7 @@ sub XiaomiBTLESens_CreateDevicenameHEX($) {
   <b>Get</b>
   <ul>
     <li>devicename - setzt einen Devicenamen</li>
+    <li>resetBatteryTimestamp - wenn die Batterie gewechselt wurde</li>
     <br />
   </ul>
   <br /><br />