I heeded the warnings of others, paid a little extra and bought mine from Ian in Utah.
I like MPP's LV2424 for being good bang for the buck; plus welcome hearing of options in same price range that might have a better auto LifFePO4 battery charge profile; while also wondering how LiFePO4 charging behaves in the more expensive equipment options that I think could cost 3 to 4 times or more as much (but not sure). I agree with your concerns about bumping float charge config way up to get more charging amp, as I also think, from some of what I read, that could or would damage LiFePO4 cells. I am leaving my Float setting at 27.2v for now.
I am glad to hear some of my testing ideas might be useful to others; while gotta say: @ 25% SOC on Battery ...What voltage was your battery then ??? Plus: going from 34 watts In to 340 Watts In on a 1000 Watts worth of PV Panels ... would still have me wondering / as in wanting to double check voltages and amp currents of the solar wires IN, ... through each and every junction to potentially find a weak connection (or too small of wire which would be heating up), or something going on. Here in Northern Calif, early January winter, @ about noon without clouds in full sun, ... with my two (6 x 360) 2070 watt arrays ... I see about 1200 -1300 watts from each of my two level w roof arrays on same angle as my about 4/12 pitched roof. In contrast, from my 3rd (6 x370) 2220 Watt array, I see about 1880 watts when my array is angled to get more direct sun (maybe 85 degree vs 90 head on sun). One thing I notice too, if I am not using the power of my solar by not having much load on my LV2424s (got config for 240ac split phase), they are throttled back in showing or using watts of PV IN until I turn on my coffee boiler, turn on my heat pump heater(s), and/or an electric heater, and/or plug in and turn on my heat gun (to see how it all works). That might be the first idea to try when you are wondering about low PV IN watts. Let us know what you find :+)
Thanks Bill, I will check everything but the only variable between the 34 watts and the 375 watts was me turning off and then on the LV2424 so that is my prime suspect right now. Also, I have three smaller panels on a different charge controller that is measured by same shunt meter as the LV2424,, so the LV 2424 was producing even less than 34 watts if any at all.
Wow, that is very interesting, you mean there are no solar watts coming in when there are no loads? In my scenario I disconnected all loads and turned off the LV2424 inverter yesterday. I will disconnect all loads tonight and tomorrow AM I will turn on a load and see if the watts increase. I am seriously considering adding a Victron charge controller and just using the LV2424 as an inverter.
also wonder where your 25 % came from? ... including what voltage showing at LV2424 LCD (depending on page of options). Just wondering
When set at bulk 27.8/float 27.8, does it never then go to float mode, but simply keep on charging in bulk mode? What would be the result if you set the bulk at 27.8, but the float at 27.7, since if the float voltage is below the bulk voltage, no current should then flow...no voltage difference to drive it? If at that point the voltage drops below the float voltage, does it revert back to bulk once more?
I got it from my shunt battery capacity monitor, I don't remember the voltage this morning the pic below was taken at another time.
Excellent questions, I have no idea, maybe someone with more knowledge will chime in. I would test it but I have kids and thus no time.
In the settings above Bulk which is often described as Constant Current changes to Constant Voltage at 27.8 volts. That is often described as Absorb and on some chargers or charge controllers can be set to terminate after a set time or when the current decreases to a set point. Float is a type of Constant Voltage mode at a lower current and is sometimes called trickle charge. I think that setting float the same as Bulk termination would just continue the constant voltage mode. It may depend if the charging source is solar or an AC powered charger. It is not advised to do that with Lithium unless there is a constant load and even then it would be better if it was set at a lower point. Assuming a 16S pack that is 3.62 volts per cell and it is not wise to keep the cells at that voltage for a long time.
I like your description Ampster, which I agree with. A side note: The LV2424s does not have a configuration adjustment for the Bulk/Absorption cycle, which is instead on some kind of internal auto program for that cycle (my take from observations/ and, from what I have read; I believe MPP's 48v models do have that config option). ...& Even though I just Ah tested my 2nd set of 8 280Ah LiFePO4s this week, I still consider myself some what of newbie to LiFepo4s/ and have this Take: ... Re Solar4FunJim's "When set at bulk 27.8/float 27.8, does it never then go to float mode, ..." ;: : : I heard one guy on YouTube saying LiFePO4 do not need float, and that float charging LiFePO4s will damage LiFePO4s. I do not believe that is true at 27.2v (which is the figure I copied from Will P's webs info on LiFePO4s page).; but do think that idea of damage from float charge might be true at higher voltages, especially when no loads are being used, translating into shortened battery lifespan (who knows for sure ???
Yes that guy is correct and I think you correctly understand the context. Lead Acid batteries need float because they self discharge. Lithium batteries do not self discharge fast like Lead Acid and therefore do not need float.
