On Tuesday, April 3, 2018 at 11:44:49 AM UTC-5, jfitch wrote:
On Monday, April 2, 2018 at 10:47:02 PM UTC-7, krasw wrote:
tiistai 3. huhtikuuta 2018 2.16.45 UTC+3 kirjoitti:
The theoretical number of times the batteries of each type can be cycled is irrelevant if they will die of old age in a number of years, even if that's 10+ years for LiFePO4 and only 3-4 years for SLA in my use.


In my experience lifetime of LFP is not better than SLA. My first battery died completely in 6 months, second had much reduced capacity after 2 seasons. Idea that chinese LFPs last thousand cycles or decade is just false.

I going on my 5th season on the instrument LFP, it currently tests the same capacity as the label says. I generally replaced the SLA at 2 - 3 years as they had lost significant capacity by then. It cost 4x as much, or about the cost of two tows. To me the benefit of holding the voltage higher throughout the discharge cycle is worth that alone.

All batteries have a self destruct clock built in, ticking from the moment they leave the factory. SLA batteries have a shorter clock, but the thing that kills them is the use: deep discharge, followed by late recharge, followed by 6 months of idle storage. LFP batteries deal with this sort of thing MUCH better than SLA.

It's too early to tell if "chinese LFPs last thousands of cycles", but I know for a fact that Chinese LiPo batteries do, as I have a large number of devices that have. Chances are near 100% that if you are buying any lithium battery it was made in China. Chances are pretty good that if you buy an SLA it was made in China, too.

Here is my admittedly radical view-point: Just like the Imperial System of distance and temp measurements and downwind dashes in gliders, the SLA battery belongs on the scrap heap of history. Get over it, boys and girls.