Batteries for Flygt pump alarm

[choperooni]

Hi all, the rechargeable batteries for my 30 year old sewage pump alarm have failed and I wonder should I swap out ni cad for nimh? The alarm unit is powered by mains and charges up the four aa cells in case the alarm circuit trips at the consumer unit. I can't find a model number on the alarm unit. Many thanks.

 

[kerching]

I would tread with great care as the technology to charge NiCad or NiMh is different to that of alkaline which it sounds like you have at present

you may well knacker the charging circuit and/or batteries

 

[Geoff1946]

I read your question as "Can you replace NiCad with NiMh".  That right?     

Unfortunately its not an easy answer as it depends on the characteristics of the charging circuit, so the right thing to do is ask the manufacturer.   

If that's impossible I would be inclined to try to get new NiCads.though I think they are becoming harder to find. 

However, if neither of the above is easy, and you're not averse to a small gamble, then in my opinion NiMh will probably be OK. 

 

[choperooni]

Thanks for your comments, wise words and I am being cautious in my approach for the reasons you mention. I think I'll approach Xylem who now seem to own Flygt. My bet would be be NiCad because that's what were in unit which was installed 30 years ago. Thanks again.

 

[binky]

30 years for a battery is an epic life span! 

 

[Geoff1946]

30 years for a battery is an epic life span! 

I agree especially NiCads.   Perhaps they've been dead for 25 years and not had a power cut ?

 

[Andy™]

slightly related... once got called to find out why a tank alarm didnt work after someone overfilled a waste oil tank.  battery powered tank alarm with flat batteries... found the power supplies on the wall further up, brand new in their boxes