A Simple Question About LiFePO4 Batteries

On 05/11/2018 02:28 PM, wrote:
But you can drain a lithium battery "all the way" (to the point
where the protection circuitry prevents further discharge) with not much
loss of battery life.


This assumes that all lithium batteries have a full-featured BMS circuit
that protects against battery abuse. That seems to be a bad assumption,
particularly for LiFePO4 batteries. Pfiffner has posted some
interesting failures he's seen there, in the previous incarnation of
this discussion.

On Friday, May 11, 2018 at 7:15:02 PM UTC-4, kinsell wrote:
This assumes that all lithium batteries have a full-featured BMS circuit
that protects against battery abuse. That seems to be a bad assumption,
particularly for LiFePO4 batteries. Pfiffner has posted some
interesting failures he's seen there, in the previous incarnation of
this discussion.

I really was just asking about the taller size battery (the PowerSonic # is PS-12100H if you want to look it up; it's about $10 more than the usual size) to see if there were a LiFePO4 equivalent.

That said, I've read Richard's posts as well as others from a few pilots who have reported relatively premature deterioration of LiFePO4 batteries. The verdict seemed very clear a few years ago. Now...? Having a $35 SLA start to slide after a few years wouldn't be as annoying as would a $100 to $150 LiFePO4 battery. Yes, the only advantage of SLA is cost...but if I have to replace both types at about the same time, that's definitive for me.

T8, I believe you were using Bioenno whereas most posts are about K2, with a few about Starkpower and one unanswered query about Dakota. I take it you're still happy with yours.

Chip Bearden

On Friday, May 11, 2018 at 11:59:03 PM UTC-4, wrote:
On Friday, May 11, 2018 at 7:15:02 PM UTC-4, kinsell wrote:
This assumes that all lithium batteries have a full-featured BMS circuit
that protects against battery abuse. That seems to be a bad assumption,
particularly for LiFePO4 batteries. Pfiffner has posted some
interesting failures he's seen there, in the previous incarnation of
this discussion.

I really was just asking about the taller size battery (the PowerSonic # is PS-12100H if you want to look it up; it's about $10 more than the usual size) to see if there were a LiFePO4 equivalent.

That said, I've read Richard's posts as well as others from a few pilots who have reported relatively premature deterioration of LiFePO4 batteries. The verdict seemed very clear a few years ago. Now...? Having a $35 SLA start to slide after a few years wouldn't be as annoying as would a $100 to $150 LiFePO4 battery. Yes, the only advantage of SLA is cost...but if I have to replace both types at about the same time, that's definitive for me.

T8, I believe you were using Bioenno whereas most posts are about K2, with a few about Starkpower and one unanswered query about Dakota. I take it you're still happy with yours.

Chip Bearden

I agree that there seems to be a wide range of quality out there and that higher price doesn't guarantee longevity (K2). Several guys have the Bioenno 12 AH battery. I know of no issues, but it's a very small sample (also worth noting the obvious fact that this technology is still evolving). I reported my test results earlier this Spring... 11.5 AH capacity after five seasons of use.

What we don't have a handle on is what all the eventual failure modes are. If it turns out that they frequently die suddenly, or sometimes die in some hazardous fashion, then that would take some of the luster off!

I may well replace mine after this season out of caution. I'm more concerned with performance and reliability than economy when it comes to batteries. I'll offer the old one for $25 so someone else can brag on economy :-).

best,
Evan Ludeman / T8