[MRCA] D Cells in Parallel

[Peter Gottlieb]

This is usually not a problem if the cells are reasonably matched. It is always a bad idea to mix cells of different age and SOC. When I worked at a battery manufacturer we always had individual cell fusing and my recently built home-made packs do the same. I use #26 Teflon wire tack soldered on, the heat melts the solder. 

Modern alkaline cells can still leak and destroy equipment so in addition to the above, it is very wise to never keep them in any equipment. 


Peter
Kb2vtl

> On Apr 23, 2018, at 1:29 PM, B. Smith <smithab11 at comcast.net> wrote:
> 
>      Its military rally season and just a word of warning about using D cells in parallel. Several of us have experienced "D Cell Runaway" when using two D cells wired in  parallel.  Evidently one cell charges the other and the battery chemistry changes resulting in a very low resistance of one battery resulting in high current drain of one of the batteries and then the other one goes South. 
>       Does this happen every time you use them in parallel?    Ans. No.    It is random. As a possible preventive measure when using cells in parallel always use fresh batteries and from the same package and date code. Also test the batteries under load to make sure that they are equal. Do not mix different brands of D cells. Do     not store the batteries in a hot environment prior to use such as the rear of your vehicle.        
>      But these new  "Alkaline-Manganese Dioxide" batteries have plenty of capacity and a single cell can easily power the typical 1.5 volt filament circuits found in most of our older military radios. So why bother using two batteries in parallel?
> 
>        When using the FT-501 holder for the BC-611 - - - I would modify the fixture to  just utilize  1 D cell. 
> 
>       This runaway phenomenon usually  occurs with the radio  power switch OFF!
> 
> WARNING: DO NOT STORE any radios or battery packs with D cells in parallel      -      -     - REMOVE the batteries.
> Z
> 
> <gicdmcppiefdlmoi.gif>
> 
> 
> 
> 
> set on or off
> BC611 battery adpataer
> do not store
> 
> 
> duracell
> 
> ______________________________________________________________
> MRCA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mrca
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MRCA at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html