[Elecraft] KX3 Please evaluate LiFePo4 battery/charger choice, UPDATE

[Fred Jensen]

On 11/22/2013 11:00 AM, Arno Dienhart wrote:

> So I understand you are using two fuses, one for each pole. What amp rating?

Yes, I put a fuse in each lead.  They're 5A fast-blow, they're supposed 
to open in less than 2ms.  I decided to tolerate the tiny increase in 
resistance for the protection.  I used the "blade" type automotive 
fuses, they make a really good, low resistance contact in the holder.
>
> My PCM includes overcurrent discharge protection at 42A with a protection
> delay time of 20 ms.
>
> Does that sound like it has the "fuse" built in?

Yes, it does, and it probably will reset once the overcurrent condition 
is removed.  Many of these packs that are capable of dangerous discharge 
currents seem to have them these days.

LiFePO4 batteries like to be stored at less than full charge ... around 
2/3 - 3/4 or so.  My charger has a "storage" cycle on it that charges to 
full and then discharges to 2/3, keeping the cells balanced.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org