LOWBAT never reaches openHAB2

Hi There,

maybe someone else has this problem. I user the Homematic binding and in general it work perfect, but i did not get any LOWBAT information into an item.

On the Homematic side i use homegear 0.7.0-1349. In the homegear log i see a lot od LOWBat information, but it never reaches openHAB.

Could someone help?


Did you create an item, that represents the lowbat channel?

Sure, i use the one from the maintenance channel

Number GfCoCt_Cellardoor_LowBattery "Batterie Kellertür Diele [%d]" <measure_battery> (gGfCoCt_Cellardoor, gBatteriesEmpty) {channel="homematic:HG-HM-Sec-SC-2:xxxxxxx:1#LOWBAT"}
The system does not care if i use NUMBER or CONTACT.


You could try the REST API to see if the low battery informations reaches OH by calling http://<you ip>:8080/rest/items/homematic_HG_HM_Sec_SCo_XXXXXXXX_MEQXXXXXX_1_LOWBAT

For me this works, also the defined item works.

Hmm, using the REST API with the channel definition gives me a 404, Replacing the : by _ gives me a 404 as well. Using the Itemname give me the informationen that the state is NULL.

Any Idea?


Try http://<you ip>:8080/rest/items to get all items first and search for the Homematic ID / Serial Number. This should give you a direct link to the item.

Nope :frowning:

With the http://<my.ip>:8080/rest/items i got something like that:

[{"members":[],"link":"","state":"UNDEF","type":"GroupItem","name":"gSecurity","label":"020 - Security Items","category":"secur_alarm_alarm","tags":[],"groupNames":["gAll"]},{"members":[],"link":"","state":"UNDEF","type":"GroupItem","name":"gDoorContact","label":"Türkontakte","category":"fts_door","tags":[],"groupNames":["gSecurity"]},{"members":[],"link":"","state":"UNDEF","type":"GroupItem","name":"gWindowContact","label":"Fensterkontakte","category":"fts_window_2w_open","tags":[],"groupNames":["gSecurity"]},{"members":[],"link":"","state":"UNDEF","type":"GroupItem","name":"gGfCoCt_Cellardoor","label":"Kellertür Diele","category":"fts_door","tags":[],"groupNames":["gDoorContact"]},{"link":"","state":"geöffnet","stateDescription":{"pattern":"","readOnly":false,"options":[]},"type":"ContactItem","name":"GfCoCt_Cellardoor_State","label":"Kellertür Diele","category":"fts_door","tags":[],"groupNames":["gGfCoCt_Cellardoor"]},{"link":"","state":"Unbekannt","stateDescription":{"pattern":"","readOnly":false,"options":[]},"type":"ContactItem","name":"GfCoCt_Cellardoor_Sabotage","label":"Sabotage Kellertür Diele","category":"secur_sabotage","tags":[],"groupNames":["gGfCoCt_Cellardoor","gSabotageAlert"]},{"link":"","state":"NULL","stateDescription":{"pattern":"%d","readOnly":false,"options":[]},"type":"NumberItem","name":"GfCoCt_Cellardoor_LowBattery","label":"Batterie Kellertür Diele","category":"measure_battery","tags":[],"groupNames":["gGfCoCt_Cellardoor","gBatteriesEmpty"]}

I only find the item with its name and the i got the following result:

{ "link": "", "state": "NULL", "stateDescription": { "pattern": "%d", "readOnly": false, "options": [] }, "type": "NumberItem", "name": "GfCoCt_Cellardoor_LowBattery", "label": "Batterie Kellertür Diele", "category": "measure_battery", "tags": [], "groupNames": [ "gGfCoCt_Cellardoor", "gBatteriesEmpty" ] }


I would assume that LOWBAT is a Switch channel, neither Number nor Contact. Did you try that?

Since this is OH2 you could check the paper UI binding to see a list of all available channels and their types :slight_smile:

I can’t (without using Homematic) - because the Homematic binding dynamically creates the Thing Types when being connected to the Homematic gateway. But @Dibbler42 should see it there indeed :slight_smile:

@rtvb Sorry, but i do not find the appropriate information. Where is it located

@Kai Kai Changed to Switch, but had not the time to check everything carefully


@Kai Seems to work, now i have to test it with some older batteries :slight_smile:

1 Like

Hi Dibbler,

how did you fix this excatly? I have the same problem. In the debug log(Karaf) i see that the value returned fron the device is “false”…so battery is OK.
But in openhab2 it doesn´t show up.
This is my item

String EGSchlafzimmerTuersensorBattery "Terrassentürsensor (Schlafzimmer) [MAP(Batterie.map):%s]" <battery> (gEGSchlafzimmerTuersensor,gSysBattery)


I definded my batterie items like this:

Switch GfCoCt_Cellardoor_LowBattery "Batterie Kellertür Diele" <measure_battery> (gGfCoCt_Cellardoor, gSystem_Batteries) {channel="homematic:HG-HM-Sec-SC-2:895298B3-A5AA-26E6-54D1-4339B9E56827:LEQxxxxx:0#LOWBAT"}

and this works. Because i am not showing the values i have no mapping.


Hi Thomas,

thx, i´ll test it.
but for me thisi is only a workaround. Mayby a problem in the HM binding :disappointed:,


Why only an workaround?

Hi Thomas,
because in my Sitemaps i use a “String” = “…Batteriestand OK”. For this i use the map file.
Now if i use a Switch i need a rule to do the same…like …IF Switch =ON…postupdate EGSchlafzimmerTuersensorBattery "Batteriestand OK"
So for me a lot more work to do :wink:

I created a group that is dynamically filled an shows only the items with lowbat. So i have only one location where i see if the batteries are ok and its is only displayed if the group has members.

Works like a charm for me.


…thats the way(dynamic groups) i filter every night the Items with “lowbat”. if there is an Item in this group i send a pushover :wink:
but on my sitemap i need a Sting