My old (well used) SLA batteries are due to be replaced, and I've ordered a new 4.5 AH lithium ferrophosphate battery (LiFePO4) and wonder if anyone else here has tried or is using one of these and what their experience has been.
From what I've read, this battery should suit my SOTA needs better in a lot of ways: 1) Larger capacity than the 1.2 or 2.6 AH batteries I carry now. 2) Lighter weight: At 1.5 pounds - this is only 1/4 of a pound more than my 1.2 SLA. 3) Wider operating temperature range: -20C to +60C so the cold and hot days won't matter. 4) Low self-discharge rate - I can carry it longer.
The version I've ordered is advertised as a direct replacement for an SLA with built-in overcharge and overdischarge protection. A special LiFePO4 charger won't be necessary, and I could use an ordinary solar panel charger if needed. I checked with the Battery Minder people who told me not to use my desulvate/maintainance type of charger on this battery.
It's a little expensive, but not by much and I'm hoping that I can carry this battery for long-term backpacking and not even bring a charger along. My portable cw rig draws 750mA on transmit and 50mA on receive so I'm hoping to have enough capacity for 4 or 5, 1-hour activations or a week on the trail.
I'd appreciate the benefit of other's experience with this.
de Fred - N7KRN
Hi Fred, Based upon the
Hi Fred,
Based upon the numbers you have stated for TX & RX current, I calculate that you will be using 0.25 AH So you should be able to get 4 summits per AH of battery capacity. You should have plenty for 4 or 5 summits to spare! Plus a spare 2AH for a small LED light for getting off a mountian after dark. HA!
73, Don KO7i
Battery
Hey Don!
Thanks for doing the math! That's what I figured too... but I'm going to run a test to be sure. I understand that battery manufacturer's don't all use the same evaluating methods. It'll be good to know what to expect from this one... if it ever arrives!
I've started looking at constant-current circuits so I can breadboard one up to draw 750mA down to a cut-off of 12V or so.
Fred - N7KRN