My first LiFePO4 battery.

The weather's been a bit crazy these past few days.  I've a photo of me taken in a T-shirt at 650m in the mountains last week at  +18 Celsius.  Last evening, I was in much the same place with full winter gear at minus 5 Celsius, in snow!

Winter returns to Snowdonia!  Last evening, with Tryfan at centre (C) MW1CFN.

 

So that hasn't made for much portable operating of late!  But it's been apparent for a while that my 15Ah gel matrix battery, though very convenient, is just too bulky and heavy to carry around much.  OK, I can put it in the backpack, but something a little lighter would be nice.

I had a quick look around today for something in LiFePO4 technology at around 7Ah capacity - a FT818ND should keep going on that for quite a while - and found exactly that - for just £55, free delivery and a charger included, though it can be charged off a solar PV system, which I use for all my batteries already.  You do need a charge controller with a LiFePO4 profile, though.

 

No more heavy lifting!

Though four times the price of a 7Ah gel matrix battery, the LiFePO4 is less than one third the weight - just 0.76kg as opposed to 2.65Kg - is largely insensitive to charge condition in storage, keeps that charge for about a year, and takes at least four times more deep discharge/charge cycles than a gel matrix battery.  In other words, in real terms, there is no cost difference, but there is a big weight saving.

UPDATE:

Had this battery for a couple of weeks now and very happy indeed with it.  7Ah capacity is perfect for QRP operation, with plenty of charge for a few hours' outing.  Incredibly light, it's like holding an empty plastic box in your hand.  My latest outing at ~4W on FT8 drained so little power that the battery was fully charged again in about 20 minutes. 

Only slight downside is that the charger produces a fair amount of RFI; the video below is of interference at 50MHz, though my antenna for that band is quite low.  At 24MHz, with a high Yagi, there was no discernible noise.  All the same, a shame, when RFI can easily be avoided through proper design.