[Elecraft] PROPOSAL: K2/10 Battery LiPO / 8AA carrier option

[Chip Stratton]

I think you would be much better off with a 4S LiFePO4 instead of a 3S
LiPO. Your fully charged voltage would be just under 14 volts, and fully
discharged around 12 volts.

I once found a 4S LiFePO4 battery on Ebay that was almost exactly the same
size as the SLAB that the K2 battery kit included, and fit inside the K2
using the existing battery strap. It worked very well, even using the
original charging circuit. Although it had a balance connector, I found
that the cells were never significantly out of balance using the K2
charging circuit. I made a point not to leave it plugged in to the mains
power supply once the battery was fully charged, but LiFePO4 in my
experience tolerates overcharging time at low currents rather well, unlike
regular LiPO. Having said all that, YMMV and it is always best to balance
charge any Li rechargeable battery with an appropriate balancing charger
and away from the radio or potentially flammable materials, etc. etc. etc.

Chip
AE5KA

On Wed, Nov 28, 2018 at 11:37 AM Ignacy <no9e at arrl.net> wrote:

> This battery has very high current potential but does not have a limiting
> board. You can connect it to K2 via a resettable 3A fuse. But I would
> choose
> Li-Ion something with less max current and PCB board for safety and
> reliability. Like:
>
> https://www.batteryspace.com/li-ion-18650-battery-11-1v-2-6ah-28-86wh-4-2a-rate-3s-s-battery-module---un38-3-passed-ndgr.aspx
>
> For many years I used 3S1 combination using flat cells inside my K2. It was
> charged at 12.8V with 1 A limit and the connection to K2 was by a
> resettable
> fuse. Keeps > 11V for about half the charge. Never a problem despite
> travelling across all continents. Very light. But I was always afraid that
> something would short causing trouble. With batteries with PCB for limits,
> the risk is far lower.
>
> Ignacy, NO9E
>
>
>
> --
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