[Elecraft] Re: Internal battery life (clarification)

[Ingo Meyer DK3RED]

Hello Bill,

> ... So I am curious how long the battery generally 
> lasts before going dead.

The time is dependent from your operating style, the installed option, the 
output power and from the style you wound the transformer for the internal 
K2 PA. I have not count the hours between charging periods. But its longer 
than I want to operate without a break. ;o)

The following is based of equal periods for transmitting and receiving, 
because i.e. I send my QTH info and receive the same info from the other 
station.

1 hour QSOs = 30 minutes RX + 30 minutes TX

If you use CW you don't transmit the whole 30 minutes, because there are 
spaces between the dits and dahs. The real ratio is about 1:1 while TX.

So the new formula is

1 hour QSOs = 45 minutes RX + 15 minutes TX

Now back to the K2. My K2 need 0.28 A while RX and 1.84 A while TX. The 
current is dependet from the installed options and more in your K2. Measure 
it with the internal meter!

45 minutes RX = 0.75 hours x 0.28 A = 0,21 A
15 minutes TX = 0.25 hours x 1.84 A = 0,46 A
--------------------------------------------
                    1 hour QSO       = 0.67 A

The internal battery contained 2.2 Ah so you can operate 2.2 Ah / 0.67 A = 
3.28 h (= 3 hours 17 minutes).

These period is valid only for hardcore QSOers. If you receive longer than 
you transmit, so the result will be greater.
-- 
72/73 de Ingo, DK3RED   Don't forget: the fun is the power!

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