Cptnvideo
Arizona - most of the time
Senior Member
Joined: 11/05/2006
View Profile
 Offline
|
No, I did not. And I don't plan to be in 32° weather either. LOL
Bill & Linda
Arizona
2019 Dodge Ram Laramie 3500 dually 4x4 diesel
Hensley Trailer Saver BD5 hitch
2022 Grand Design Solitude 378MBS
1600 watts solar, Victron 150/100 MPPT controller, GoPower 3kw inverter/charger, 5 SOK 206AH LiFePo4 batteries for 1030 ah
|
StirCrazy
Kamloops, BC, Canada
Senior Member
Joined: 07/16/2003
View Profile
|
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 ![[emoticon]](https://forums.motorhome.com/sharedcontent/cfb/images/wink.gif "wink") . 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 bocks
Steve
2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100
|
Cptnvideo
Arizona - most of the time
Senior Member
Joined: 11/05/2006
View Profile
Offline
|
TechWriter, I guess I should explain what I meant about waiting for warmer weather.
We are currently NW of Phoenix with the highs currently reaching the upper 50s and the lows going to upper 30s-lower 40s. I'm a wuss and waiting for temps above 60° before I do the install.
Per SOK, the BMS will shut down charging at 0°C BATTERY temp (not ambient temp), but will allow discharge to a lower temp. Charging would be turned back on at 5°C. I don't know for sure but I would expect it would take a few hours below ambient freezing for the cells to get to freezing temperature. Therefore, I don't see the need for a heater.
|
theoldwizard1
SE MI
Senior Member
Joined: 09/07/2010
View Profile
Offline
|
Cptnvideo wrote:I don't know for sure but I would expect it would take a few hours below ambient freezing for the cells to get to freezing temperature. Therefore, I don't see the need for a heater.
Charging and discharging will produce some heat.
|
profdant139
Southern California
Senior Member
Joined: 11/14/2005
View Profile
Offline
|
This post describes a DIY battery heater -- it is a little too sophisticated (well, actually a lot) for my skills or lack therof. But it looks to be a doable deal for technically-minded folks:
Li Battery Heater DIY
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and text
About our trailer
"A journey of a thousand miles begins with a single list."
|
|
|
3 tons
NV.
Senior Member
Joined: 03/13/2009
View Profile
Offline
|
profdant139 wrote:This post describes a DIY battery heater -- it is a little too sophisticated (well, actually a lot) for my skills or lack therof. But it looks to be a doable deal for technically-minded folks:
Li Battery Heater DIY
Well, if not so DIY inclined, a drop-in battery might be a far better option…
3 tons
|
PerryB67
Lanesboro, Minnesota
Full Member
Joined: 07/07/2017
View Profile
Offline
|
TechWriter wrote:Did you get the SOKs with heaters? The following is from SOK's web site:
SK12V206H designed for cold weather using! Can safely charge at temperatures down to -20°C (-4°F) by a standard charger or solar charger. The heater pads which draws power from the charger itself,battery cells no power lost.
The Sok heater only works when you are connected to a power source, i.e. plugged in at a campground, or during the day when you have adequate solar. If you're boondocking, when we would want a heater, they don't heat at night when it gets cold.
Enjoy,
Perry
2016 Bigfoot 25RQ
2019 F150 Max Tow, Max Springs, 3.5 EB Quad Cab
Victron 712, Victron 100/20, Victron 100/30
160 Watts on the Roof, 100 watt portable
Two 100 ah SOK LFP Batteries
|
|
