[NSRCA-discussion] NiMH Question

[John Ferrell]

I am not aware of ANY sudden NiMh failures in non hostile environments. The 
failure rate in airplanes (recips) seems to be pretty high. They last a very 
long time in my digital camera. I can keep watch over them in my 
transmitter.

I have not given up on NiMh as a power source in an aircraft but it will 
require careful battery maintenance if it is to be workable.

John Ferrell
http://DixieNC.US

----- Original Message ----- 
From: "Jerry Budd" <jerry at buddengineering.com>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Friday, February 24, 2006 11:55 PM
Subject: Re: [NSRCA-discussion] NiMH Question


> >I find the same procedure also works well for NiCad's. If you reset
>>the peak charger and restart it you will cook the  batteries and
>>suffer short battery life. NiCad's normally fail shorted and you
>>have enough power to land. NiMh's normally fail open and you will
>>need another airplane to go with your new battery.
>>
>>That is also why I use NiMh in the transmitter and NiCads in the flight 
>>packs.
>
>
> John,
>
> Why, if you are concerned about a cell failing "open", is it OK to
> use NiMH cells in your transmitter but not in your flight packs?
> They're both single string systems, an open cell failure in either is
> going to result in a catastrophic failure and loss of aircraft.
>
> Are you thinking that the flight environment (flight loads,
> vibration, etc) is the primary contributor to the likelihood of a
> cell failing open?
>
> Thx, Jerry
>
> -- 
> ___________
> Jerry Budd
> Budd Engineering
> (661) 722-5669 Voice/Fax
> (661) 435-0358 Cell Phone
> mailto:jerry at buddengineering.com
> http://www.buddengineering.com
> _______________________________________________
> NSRCA-discussion mailing list
> NSRCA-discussion at lists.nsrca.org
> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>