[Milsurplus] Error correction for "Mil Spec Radio Gear" Volume 2

[Mark]

There are two kinds of errors that I tried extremely hard to avoid 
while writing "Mil Spec Radio Gear" Volumes 1 and 2.  The first is 
any sort of mistake that could cause injury.  So far so good on that 
one!

The second is any sort of goof that could result in equipment damage.  
It appears I slipped up on that one and I'm issuing this correction.

While I was sitting at WA4VAG's space at Dayton selling my books 
and tending the other guys' stuff, Peter Gottlieb from A123 Systems 
stopped by to point out an error I'd made in MSRG-2 on page 28 and 29 
in the "Lithium batteries" section of the battery pack write-up.  I 
write that the A123 lithium nanophosphate cells can be charged at .25C 
until the pack reaches 4.2 volts per cell.  This last is okay for 
Li-ion cells, but not the newer nanophosphate type.  Peter said the end 
voltage is too high and will risk damaging the A123 cells.  I've read since 
then that tests have been conducted charging Li nanophosphate cells on 
regular Li-ion chargers that charge to 4.2V and, while there was no swelling 
or overheating, it did result in significantly shortening the life of the 
cells. 

Peter said the end voltage for a full charge should be no more than 3.7 
volts.  He also mentioned the charge rate can be a maximum of 10C and the 
cells should not be discharged any further than 2 volts.

As always, I recommend carefully studying the specs for your particular 
battery before designing your own charger.

--Mark Francis
  KI0PF
  
There was a young lady named Bright
Whose speed was far faster than light;
She set out one day
In a relative way
And returned on the previous night.