I take it that each low battery was on a separate series set?
Could it be that each battery was not at full charge because of in series/balance, and the led's where showing voltage from the series string?
I was supposed to hook mine up today. BUT, I spent my time dealing with an incident, so didn't put it up. You'll likely need heavier gauge wire from the combiner box to the inverter, depending on how many you are putting in parallel. You'll want to price that and factor that into your plan. I have 10 gauge for PV to combiner, 4 gauge for combiner to the inverter.I'm just realizing I should install a combiner box at the solar panels. I'm planning six 300 watt panels at 24v. Each panel generates 12.5 amps, so six 15 amp breakers in the Midnite Solar MNPV6 combiner box?
Well, you can see I have setting 20 at 25.5. Honestly, I haven't seen the 20 and 21 settings play a role in any way.Some interesting info to share. The past few weeks I've been having one of my two inverters faulting with an 06 error. Output voltage is too high. I've been working with Ian and MPP solar to troubleshoot. When Ian looked at my settings he had me change a few things as he had seen this before. I did tweak the settings as he requested and (knock on wood) things appear to have stabilized, however, I'm not ready to call the problem resolved.
Some background on my setup:
2 inverters LV2424's running split phase
8 Panels 2600 watts with 1300 watts tied to each inverter
6 Lion energy batteries for 285ah
My operating strategy for the system has been to maximize my investment by pushing both the panels and the batteries to use the power generated/stored in each. During the day I run loads higher than my capacity to drive power generation of the panels. If I don't do that they don't produce. As I'm not generating enough power for the loads the batteries pick up the slack and begin to drain. At a certain point, the inverters start to backfill with AC power so all three are feeding power. Once the sun goes down the panels turn off. The batteries continue to drain and then right before low voltage cutoff the AC charger bulk charges the batteries. After a few hours, the charge is complete and I'm running solely off batteries until the sun comes up and the cycle repeats. I don't want my batteries sitting there unused as I have many thousands invested in them.
My low voltage cutoff is 23 Volts
Bulk charge (was) 29.2
Float (was) 27.2
Setting 20 (battery Stop discharging voltage when grid available) was 23
Setting 21 (batter stop charging voltage when grid is available) was 29
1) Bulk charge setting I got from Lion energy
2) low voltage cutoff I got from experimenting and accounting for slight variations in the batteries themselves + a little buffer to ensure my batteries began charging before hitting the BMS cutoff
3) Setting 20 was set similar to Low voltage cutoff thinking that would be the voltage at which the batteries would begin to use the grid to charge
4) Setting 21 was set as close to bulk charge thinking that should be the same or close to bulk charge voltage.
Neither setting 20 or 21 are well documented.
Troubleshooting my issue.
1)Ian first had me lower my bulk and float settings down by .5 volts to 28.7 and 26.7 respectively
2) He then had me change setting 20 to 24 volts and 21 to 26 volts
I asked him to explain the logic behind the changes in settings 20 and 21 and he explained the following. The bulk charge and float voltages (17 & 18) are for the SOLAR charging only. The AC charger is not "designed" to be bulk charging every day and is instead to be used as a top off when the batteries dip down. While the units have two chargers the bulk charging should be handled by solar and the top off should be handled by AC power. I was effectively doing the inverse as my loads were exceeding my solar generation (as explained above) Ian felt having setting 20 set the same as low voltage cutoff was a red flag.
So how it works with the revised setting is as follows: when the batteries get to 24 volts (setting 20) and ac is available, it will begin to supplement with AC charging to bring the batteries back to 26 volts (setting 21).
So far things have been stable the past three days. I should add however that I feel largely unsatisfied in my understanding as to how I could be running for 3 months with my original settings without issue, now have this problem, and how these changes may have fixed it. I really just wanted to relay the details about how the settings are "designed" to interact with one another
Yeah. Same conclusion. Perhaps the BMS does voltage regulation. When connected to the bank, that can perhaps impact the LED readout too, making it less reliable when the bank has a load or is being charged. I haven't 100% proven this, yet. But, that's my current interpretation based on what I've seen.I had my batteries BMS hit low voltage cutoff just one time which made me realize when they are discharging they're even and flat. I could check them and they would all have the exact same voltage. but when they get to the very end they can drop off the cliff at slightly different rates. I had one that hit the BMS cut off out of six. I avoid that now by not allowing the pack to go below 23 volts or 11.5 volts per battery.
I just got some more information about my battery charging options when two or more MPP LV2424s are configured for USA spec 240ac split phase. I am not so happy with the options I just learned about from Ian at MPP in USA. I am posting my challenge to MPP in Taiwan for a firmware update that might make their great bang for the $ buck LV2424 even better: (via email dialog posted below with a link to this forum thread: (Hope this is not too long to post here:handicap for my wanting to be able to use my 4000 watt 120 ac Inverter Generator for AC INPUT to just one LV2424 (w three LV2424 currently wired for 240ac split phase) for a battery charge option. I currently think that is just not available w 240vac split phase configuration;
I think you have bigger problems than just ac charging. The correct configuration for a split phase mmp setup is to have two 120volt circuits feeding for not just battery but for any ac input. If you're running a 240 volt appliance and, the inverters and batteries are overloaded how will that appliance continue to operate when it cuts over to ac power and you have just one 120 volt leg?I just go some more information about my battery charging options when two or more MPP LV2424s are configured for USA spec 240ac split phase. I am not so happy with the options I just learned about for MPP in USA, and posting my challenge to MPP in Taiwan for a firmware update that might make their great bang for the $ buck LV2424 even better: (via email dialog posted below with a link to this forum thread: (Hope this is not too long to post here:
To Ian (USA MPP), and MPP headquarters in Taiwan
(Please forward this message to MPP in Taiwan.
cc: DIY Solar Forum Thread:
REQUEST to MPP in Taiwan Re: LV2424 Generator to Battery Charging Options:
I would like to be able to use a 120vac Inverter Generator to charge my battery bank
when I have two or more of your LV2424 configured for USA standards. 240vac split phase.
Re: Dialog with MPP in USA (attached below.)
I am Sad to get this new lawyer of information: I believe I understand it properly.
If I want to use a 120vac inverter generator on one of my three LV2424 when they are configured for 240 split phase,
... that is possible if I reconfigure one LV2424 back to Single Mode configuration, which I would leave connected to the same battery bank;
... BUT I have to the solo mode LV2424 120vac OUTPUT to a different separate sub panel.
I am sad to hear that is the way it IS with MPP' LV2424s when configured for 240vac split phase.
I already have my sub panel configured in fine shape. I do not want to re wire a new separate sub panel,
to get a 120ac source battery charging cycle going via the LV2424 internal battery charger; and doubt I will go there.
I might just reconfigure all three of my LV2424 in daisy chain for 30 amp 120ac to be able to use my 120vac Inverter Generator as back up option for battery charging cycle via the LV2424 built in 60 battery chargers; ... and say good bye to MPP' LV2424 240ac split phase.
I image THAT configuration would take 120vac grid or inverter generator input for a battery bank charging cycle option.
For me, If I reconfigure three LV2424 for 60 amp 120vac, I would have to figure out something else for my one 240ac 1/2 hp water pump.
I Do NOT want to have to buy a 240v ac inverter generator (when I have two new 120ac inverter options now), or a separate 60 amp battery charger to be able to be able to initiate a back up for charging cycle on my solar system battery bank. !!! Personally, it is frustrating for me to learn about this limitation after getting my solar project wired and working. I wish there had been a clue in the promotional information I studies before I purchased (I did not see this limitation coming. Is there any heads up info. about this shortcoming ?).
If this is possible; I Request MPP do a Firmware Update Fix for this Significant Handicap. I challenge MPP to make it possible for me to charge my batteries with just one leg 120vac INPUT from the grid, ... or from a 120ac inverter generator; when two or more LV2424 units are configured for 240vac split phase. Is that Possible?
Please let me know if that is a possibility; in the realm of MPPs engineering dept. and its' firmware update options. I want to know.
I think some folks on the DIY Solar Forum thread I am involved with (where I posted this same message) would also like to know.
Will MPP take this challenge on, to improve their great bang for the $ buck, LV2424 product, ... to make it an even better?
To MPP Taiwan, .... Please Let Us know IF an update (that would address my articulated challenge) is in the realm of possibilities.
Cordially, William Self in Northern California
***********
previous email dialog wit MPP in USA:
> William.
>
> golden rules for AC charging.
>
> If you are configured for split phase ouput , charging will only
> occur with split phase input, etc ( input has to match output, even
> on your third inverter )
>
> Option, have all three inverters on the same battery.
>
> Two as split phase, the third, unaffiliated (use on a separate
> circuit for 120V only) charge your generator via this third unit.
>
> Ian
>
> Ian Roux
> usa-mpp-solar.com / store / manuals / sales
> 801 403 0336
> Utah USA
>
> *****************
> On Mon, Jul 27, 2020 at 2:27 PM -0600, "Bill Self"
> <williamaself@yahoo.com> wrote:
>
>
>> LV2424 Generator to Battery Charge question:
>>
> I have three LV2424 All In One units I purchase from you on eBay
> (March 2020); now configured for 240vac split phase. I like em with
> a few questions.
>
> I can get the Battery chargers activated and working (only) when I
> apply both legs of 240 vac split phase to INPUT to all 3
> inverters.
>
> 120vac IN to one LV2424 worked great for battery charging only in
> solo mode (by itself) only when wired for one 120ac line in, and
> one 120vac out.
>
> I would like the option to charge my batteries via one of my 120ac
> Inverter generators, on my three LV2424 All In One when configured
> for 240vac split phase, and currently have not figure out how to
> make that work.
>
> I think I may have to reconfigure to parallel daisy change/ three
> LV2424 for 60amps 120vac if I want to charge my battery bank with a
> 120ac inverter generator. or go through the hassle of reconfiguring
> my 240ac split phase to drop one LV2424 out of the config, and put
> it back to solo 120vac mode to get my 120vac Inverter Generator to
> a battery charge option; or purchase a separate battery charger
> (even though I have three 60 amp chargers inside my 3 LV2424 ....
> I am kind of frustrated with my perceived options for charging my
> battery bank with my 120ac Inverter generators.
>
> Questions:
>
> Is there a way to charge my batteries with a 120vac Inverter
> Generator when I configure two or more LV2424 for 240vac split
> phase in the USA?
>
> Does configuring 240vac split phase require me to have 240vac
> split phase Inverter Generator if I want the option to charge my
> batteries via generator; when configured to 240vac split phase ???
>
> Cordially, William Self
> in Northern California
I do not understand how your question and statements are relevant to my desire to get a battery charging cycle going via 120ac IN to just one, or more of my LV2424 All In One Units when they are configured for 240ac split phase. I want this back up battery charging option for when there might be no grid power for a few days on some possible cloudy day cycle. ... Kind of comes from the realm of my "Be Prepared" Thoughts.I think you have bigger problems than just ac charging. The correct configuration for a split phase mmp setup is to have two 120volt circuits feeding for not just battery but for any ac input. If you're running a 240 volt appliance and, the inverters and batteries are overloaded how will that appliance continue to operate when it cuts over to ac power and you have just one 120 volt leg?
missing from dialog to make a little more sense / from Ian, in prompt response to my questions: ... The third inverter (taking one of my three LV2424 configured to 240vac split phase/ & reconfigure one to single use mode on same battery bank/ leave the other two configured for split phase) will be out of synch with the other two in split phase, so it will need to supply its own panel of loads. Does that make sense? You will just remove some loads off the split phase set onto their own panel. ... IanI am Sad to get this new lawyer of information; I believe I understand this properly.
This was/is the issue:Panels are also supposed to be grounded.
On a side note if they don't allow you to back feed, (or if you get no credit for it) then consider maybe a thermal dump or cooling dump.
That's good to know. Thank you.This was/is the issue:
I'm running the output Solar-Util-Battery and that solved it. When I get more pannels, I'll try bonding the neutrals.
That's good to know. Thank you.
Fortunately, it's not an issue if you are running it to a Reliance Controls transfer panel connected to your main. With that setup, your house wiring continues to use the neutral and ground from your main panel buses, only switching the hot when you transfer. The ground and neutral of your incoming gen (your inverter) gets connected to the main ground and neutral bus in your main.
The result is both your AC in and out ground and neutral of your inverter get connected to your main panel bus bars.
@Bob142
That's good to know. Thank you.
Fortunately, it's not an issue if you are running it to a Reliance Controls transfer panel connected to your main. With that setup, your house wiring continues to use the neutral and ground from your main panel buses, only switching the hot when you transfer. The ground and neutral of your incoming gen (your inverter) gets connected to the main ground and neutral bus in your main.
The result is both your AC in and out ground and neutral of your inverter get connected to your main panel bus bars.
@Bob142
Erik, great information. this is how I have my Mpp connected, it goes through my Reliance Control transfer panel and allows me to pick which circuits to use with my inverter . Also lets me use fewer circuits when my panel output is low from cloud, rainy days and my batteries do not get fully charged. I wish more people with use the Reliance transfer panel for connection to their AC panels. When using the Reliance transfer panel there is never a chance to back feed the grid.That's good to know. Thank you.
Fortunately, it's not an issue if you are running it to a Reliance Controls transfer panel connected to your main. With that setup, your house wiring continues to use the neutral and ground from your main panel buses, only switching the hot when you transfer. The ground and neutral of your incoming gen (your inverter) gets connected to the main ground and neutral bus in your main.
The result is both your AC in and out ground and neutral of your inverter get connected to your main panel bus bars.
@Bob142
Yeah, I love it! Very happy.Erik, great information. this is how I have my Mpp connected, it goes through my Reliance Control transfer panel and allows me to pick which circuits to use with my inverter . Also lets me use fewer circuits when my panel output is low from cloud, rainy days and my batteries do not get fully charged. I wish more people with use the Reliance transfer panel for connection to their AC panels. When using the Reliance transfer panel there is never a chance to back feed the grid.
I just got some more information (awhile back) about my battery charging options (via a 120vac Inverter Generator) when two or more MPP LV2424s are configured for USA spec 240ac split phase. I am not so happy with the options I just learned about from Ian at MPP in USA.