S Davis wrote:
StirCrazy wrote:
otrfun wrote:
StirCrazy wrote:
otrfun wrote:
theoldwizard1 wrote:
. . . What I don't know is if below freezing will affect the battery life while discharging or storing.
Specs vary from manufacturer to manufacturer, but generally speaking, maximum recommended discharge current tapers downward as temps drop below 32f or so. Probably wouldn't want to do more than a .10c - .15c discharge at temps below, say, -10c (14f).
Long-term storage recommendations are not too stringent. If you follow the temp recommendations for charging (typically 0-40c; 32-104f) that should be acceptable. If you want the absolute best for your cells, strive for 25c (77f) and 30-50% SOC.
the specs for the new cells I ordered are pretty good that way, 0.5C discharge down to -30C short term storage of a month -40C/F long term storage -25C and charger from -5C to +60C. but it totaly does depend on the manufacture and for premades, they tend to add a little more of a buffer so they have less warenty clames they have to pay.
Very impressive. As far as advertised specs, it can work both ways. Make them conservative so they can reduce warranty claims, or make it look like their cells walk on water to sell more cells/batteries. Me, I tend to give the research and testing produced by independent labs the most creedence.
these are the new K cells from EVE and the specs are from eve's testing sheets not a salesman ;) . now am I going to set them to charge ar -5C, naa I'll keep it at +1 as my batteries are inside the living space so will never get that cold anyways, I may test the cold discharge though... well then again naa, I aint going camping at -30C haha, but the thing of interest to me was you can short term store much colder than long term (short term they describe as 30 days or less) and the fact that they seam to be a significantly more robust than the normal 280AH cells rated at 5000 cycles (100% to 0%) instead of 3500and I realy like the new double tapped termanals on them two bolts for power path instead of one skinny post.
Steve
They are not much more robust, they changed the testing specifications. The older LF280N that I have are rated at double the amp draw, 1c for 3500 cycles with a compression fixture. The new LF280K are rated at half that at .5c for 6000 cycles with a compression fixture.
Hmm, I just checked that out again and yes there was a cycle test chang, but eve actualy weighed in on it and they are a more robust construction and will still have more cycle life than the normal 280 which is why there being discontinued and the N and K will be the only two but the N are for local chinese sale only. but thats not the reason I am getting thoes ones, its the termanal blocks they have.
new bocksSteve
