Battery backup for Honeywell ST699B

[Niscars]

I think that the battery backup for my Honeywell ST699B CH Programmer has failed. Does anyone know if there is a replacement battery available or am I looking to have to change the whole unit ? Thanks.

 

[corgiman]

have you pressed reset??

 

[Niscars]

I should have been clearer in my original post. The unit works fine most of the time but if the power is lost then all the settings are forgotten.

I can't find a reset on the unit and there is no mention of it in the instructions. Is it inside ?

 

[corgiman]

Doh sorry my fault think of the wrong programmer

Is this your one

http://content.honeywell.com/uk/homes/Catalogue/Heating Controls/2.10 ST699.pdf

if so I dont think they have a reset, they do fail alot so maybe and idea to replace it.

sorry

 

[Niscars]

Yes that's the beastie. Looking at the pdf file supplied via the link, it states that the battery backup has its own charging circuit so I suspect it is not replacable and will require a new unit.
Many thanks for your assistance.

 

[Agile]

Those are very neat and easy to use units which have been made for about 20 years and are probably still made.

The battery was originally a NiCad and is soldered onto the PCB. Its an industry standard part and can be easily changed by anyone who can do electronics soldering.

Tony

 

[DP]

The battery on your programmer is fitted between two 'springy' plates. Remove the battery (note orientation) and source one from RS or Maplin. You will (more than likely) only be able to get hybrid nicad ( which is a better alternative) with solder pins. File these pins flush with face of the cell, then simply insert between the 'springy' plate (observing polarity).

Ensure cell is disposed NOT in the bin but recycled. Nicads can end up in water and then you end up drinking the stuff

 

[Agile]

I would recommend soldering the new battery into position rather than relying on "springy" contacts.

Reducing the possible failure points is better.

Tony

PS Web search failed to find any "hybrid nicads" although good basic battery info at http://www.powerstream.com/BatteryFAQ.html

I conclude its another of these things only found in Scotland.

 

[corgiman]

mind you changing the battery wont suddenly make the programmer work will it, its only a back so as you dont loose your settings

so why bother, its a lot hassle changing the settings once in the blue moon that the elastictrickery goes off innit??

Your isnt working is it??

 

[DP]

Maplin, any where in Britain, will sell you the battery.

See link http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=30958&doy=18m3

Afor mentioned timer is very popular (according to Honeywell)