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Still seems kind of expensive even if the 5000 life cycle is accurate.Originally posted by Dmonicle View Post
A napkin calculation would say if I can get 1000 wh out of it (~83% DOD, 12v x 100Ah = 1200wh) for say 4500 cycles (5000 might be a stretch) that would come to about 4500kWh over it's lifespan.
If I purchased that same 4500kWh at say $0.15/kWh (which is $0.03/kWh higher than my avg charge) that would cost me ~ $675. Which is still less that what that battery would cost.
The math does not make that battery worth while to me or anyone that has a low charge rate. -
But that rated .5C5 charge and discharge rate would be attractive to someone with infrequent extra heavy loads or limited winter charging hours.
That and the PSOC operation mode.SunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
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I found these two here in the USA. Has anyone tried either of their batteries?
STARKPOWER "UltraEnergy" ENERGY STORAGE BATTERY:
http://store.starkpower.com/12V-100A...tery_p_24.html
Smart Battery
http://www.lithiumion-batteries.com/...lar-batteries/Comment
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No, but if they expect you will get 8-10 years life, why do they only warranty it for 1 year?Originally posted by Dmonicle View PostComment
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Neither of them recommend stopping the charging at 80% to prolong both calendar and cycle life, for what that is worth. This seems to me to show a lack of understanding of the RE market they are trying to sell into.Originally posted by Dmonicle View Post
They recommend 14.4 to 14.6 while the 80% SOC value is closer to 13.6.
This correlates with the two seemingly contradictory statements that there are and are not readily available off the shelf charging systems for LiFePO4 and other Li batteries.
A lead acid charger, with an Absorb voltage of 14.2 and up, will not flat out overcharge an LiFePO4 battery, so in that sense there are chargers available.
But for best life you really need a set point closer to 13.6, and in that respect there are not mass market chargers that have that as a preset.Last edited by inetdog; 10-11-2015, 08:24 PM.SunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
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Could a CC like a Midnite Classic 150 be programmed to properly charge these LiFePO4 batteries?Originally posted by inetdog View PostComment
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That battery looks expensive compared with building one from individual LFP prismatic cells off the boat from China.Originally posted by Dmonicle View Post
What is your application?Comment
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Solar battery bank for a small off grid back up setup.Originally posted by Living Large View Post
So far all I own are 4 x 215 panels.Comment
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Yes, most of the more advanced chargers have controls where you can reprogram the settings. That takes care of the Over Full charge end, the Inverters need to be programmed to shut off before the battery is drained Too Low. Again, the higher end inverters can be programmed to do this properly too. That just leaves the user to insure the pack is properly commissioned and balanced for the first few weeks till it stabilizes.Originally posted by Dmonicle View PostPowerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-ListerComment
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And very importantly, NO TEMPERATURE COMPENSATION, and certainly disabling any sort of "EQ" cycle.
There are a lot of fly by night LFP battery distributors out there, especially when they dangle the "drop in" carrot in front of you. Do your homework first, and you can rest easier without succumbing to high-priced / low quality "drop in's".
Look for GBS, CALB, Winston, and A123, Kokam, LG unless you absolutely know what you are getting.
I HIGHLY recommend sticking with reputable battery dealerships, and not some fly-by-night online garage.Comment
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Yes. And if you use the WhizBangJr. with a shunt you can even set the precise .05C (or whatever) value for ending the Absorb (constant voltage) stage and then set the Float voltage low enough that it does not try to charge the battery at all. (Low self-discharge compared to Lead Acid).Originally posted by Dmonicle View PostSunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
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In addition to the Midnite, add the Outback MX or FM controllers that will also allow for setting the end amps at x-voltage.Originally posted by inetdog View Post
~CrazyJerry[B]I'm around...[/B]Comment
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If one just needs an off the shelf charger of high quality that works ok with lifepo4, then the SAMLEX SEC series does a fine job.
Although intended for lead-acid, you have user adjustable dip switches for gel or flooded, (14.1 to 14.4v). I run mine at the gel setting which set for 14.0v, takes the cells up to about 95% SOC. Although as discussed before, voltage isn't everything, but it gets the job done. If you want to take it to 14.4v you can. Note that I'm not going into balancing aspects here.
Similarly, for 24v systems, their 24v SEC line (black / yellow) allows you to set a conservative 28.2 or 28.8v. Let's talk voltages here, not just "canned" presets. The analog steam-gauges are actually useful for across the bench checks.
So far the Samlex SEC series are probably the most convenient chargers I've found that can be shoe-horned into lifepo4 service - especially because you can set a slightly conservative lower setting of 14.0-14.1v with gel.
And the float voltage is low enough that it won't harm a lifepo4.Comment
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