Hi guys,
Just had a thought about harvesting power a bit more efficiently..
I currently have a bit over 5000w of solar being regulated by two devices. I have a bit over half going to an apollo t80 (purchased before I was enlightened) and the balance going to a classic 150. My battery bank is 1600ah in 24v config that can safely accept 93 amps (10% of c10).
I have both regs limiting output amps so i dont go significantly above the battery input charge limit..
My thought was.. can the classic be made to limit battery input amps as apposed to regulator output amps.. In order to take into account big loads such as pool pumps or ac units..
If it can already - please share the knowledge.
If it can not, is it theoretically possible? what can I do to help
Cheers
I don't get why you want to limit battery input amps . And how is that different from the controller output amps ?
The Classic will supply the power to the big loads if available from solar - and it is not going effect the charging current. For example if the Classic is regulating charging to 10 amps and you suddenly have a load of 30 amps dc - the extra 30 amps will basically go right to your inverter . The Classic will still maintain the 10 amps charging current - depending on what state it is in . If it is in Absorb then unless the voltage drops because of the load , then the Classic will supply the 40 amps ( if available) 30 to load, 10 make it to battery. If you have your amps output on the Classic restricted below 40 amps lets say to 30 amps - then you will only get that much out.
Larry
As its understood, Midnite has that feature on the drawing board. But it has been there a while and it sounds it may be another year....
What he means is to be able to limit the current going INTO the BATTERY instead of the current
coming OUT of the MPPT controller because that current coming out of the controller does NOT
all go into the battery.... That is, unless you didn't have any DC loads like an inverter etc...
But I suppose there wouldn't be any need for a battery bank if you didn't have any loads
to such down the battery.
This limit would be done by way of the Whizbank Junior battery shunt sensor that could
tell the Classic when to limit its output current. This feature all by itself is pretty easy
actually EXCEPT that if there are more charge controllers in the system, it won't be
as easy to communicate that information to all of them and have them all limit
proportionally. It's not all that hard either but that is what would take the majority
of the work.
Also, since you have the Apollo TS and the Classic, I suppose the Apollo could just do
all that it can and let the Classic limit itself as long as the Apollo doesn't charge higher
than you want.
That being said, this feature should come some time.
I just can't say exactly when.
boB
Thanks boB,
What you describe is exactly what I was suggesting.. I would think that the wizbang jr would be installed in between the charge controllers and the batteries so it would 'see' the current going in and have the classic adjust as it sees fit. In my case, the T80 would not be able to limit based on output from the wizbang jr (unless I could get the Apollo people to work with you guys - not likely). The Apollo does have aux in/outs but I don't think they are proportional inputs to use with an output ignal from the wizbang/classic. I'll have to dig out the manual.
Anyway, thanks for the info and Im looking forward to what you guys come up with next
Cheers
Have the same issue and waiting for this function ;)
see my posts ...
Big thumbs up, when this function will be included! ;)
On my system I have 48V 230Ah battery bank and must limit the Classic to 23 Amps because the 10% charge max.
But it the classic sould be able to deliver more amps and I have the load, the classic can not "see" this and will not give more then these 23 Amps.
If I don't cut it at 23 Amps it would cook my batteries with more then 30 Amps in best sun.
Quote from: binkino on October 02, 2015, 08:22:13 PM
Have the same issue and waiting for this function ;)
see my posts ...
Big thumbs up, when this function will be included! ;)
On my system I have 48V 230Ah battery bank and must limit the Classic to 23 Amps because the 10% charge max.
But it the classic sould be able to deliver more amps and I have the load, the classic can not "see" this and will not give more then these 23 Amps.
If I don't cut it at 23 Amps it would cook my batteries with more then 30 Amps in best sun.
If you put in more than 23 amps doesn't the voltage rise quickly , putting it into Absorb, and then it regulates the current down ? It won't always put in maximum current when in Absorb . Are they flooded lead acid batteries ?
Larry
Yes, the 0.1C "rule" is not inviolable. However the higher you go the bigger the risks, and if things go wrong the bigger the mess. Hence 0.1C is a good place to be for FLA. For AGM you can go to 0.2C comfortably, and in certain good quality brands even higher. However watch the temps and make your own (informed) call about it.
Or... get into lithium and charge away to your hearts content.
Zoneblue - just looked at the write up of your system . That is an excellent review of the Classic .
What kind of lithium batteries are you using ? I think I only saw AGM in your write up.
Larry
The AGMs are still going. Now three years old. Next bank will be lithium.
Still trying to "finish" the install. Combiner, SPD, AXS, and tidy up all still sitting in the corner.
Nice neat looking job on that zoneblue .
Here is my post to this topic:
http://kb1uas.com/mnsforum/index.php?topic=2555.0
I am just actualy in the situation, that this function would be more then neccessary.
I had problems with my 230Ah AGMs and brought them today to the dealer for meassuring/testing.
Because one again failed in its capacity and I also let them check the other two batteries.
One was changed some weeks ago.
So, as I am "off grid" most time thanks to the midnite, batteries and inverter.
It is impossible to drive the charger with the inverter without batteries, but I see no sense to "waste" the energy :D
So I take the old 27Ah batteries from my e-scooter (like these 50ccm scooter, just electric) and connected them to the system.
Yes, I know with 27Ah I don't get the big price - but it is better then nothing and on day I can feed my home with energy instad of paying for the energy.
So the situation, they are rated by max. charging of 5 amps.
If I set the classic to 5 Amps, it will rise and fall with the volts, switches from and back between grid and batteries.
So I had to set to 10 amps, hope the inverter will need enough energy, that the batteries are not blown.
So you see, it is more then importand needed to have a function, that watches the charging current and regulate the amps.
Specialy today I am very sad about missing this function. I can not sit here all the time and regulate all couple of minutes the amps manualy. (also the changed amps in the classic settings are not in real time changed... takes a time... why?)
So hope you all understood the situation ,,,, and my english ... once again ;-)
My advice is if you need to get new lead acid batteries to replace old ones - ask if you can get flooded instead of AGM . They are longer lasting and you can do maintenance and check the specific gravity on each cell to make sure all is well.
Larry
yes thanks that is right, today I know this all ...
the thing was in my situation, there were AGM build in from this untrustworthy company and (see my story on www.a68k.de/pv/ but it is in german)
and after I found out that 2 batteries are 'dead' I had to get very quick new batteries and it was most the money thing
Sure, the next batteries will be either OPzS or like that, or something better - but next year.
Meanwhile we watch the battery market, whats new and coming on :)
But I do not give up the hope (we say, the hope is dying at last) that we can have this function ;)
maybe you should get lifepo4 batteries. they take a much higher charge and can be discharged lower.
Binkino, re: your signature 1.21GW? sorry - not on my PV
please tell us how many panels you have as this is a commercial amount of power, if you have 1.2 Gw you should be selling into the grid....!!!
Hi Westbranch
I believe it is a reference to time travel in "Back to the Future"
Cheers
OK, never saw it, even now nor 25 years ago... :o
Quote from: SuperTed on November 01, 2015, 04:59:17 PM
Hi Westbranch
I believe it is a reference to time travel in "Back to the Future"
Cheers
that's right, just a funny ref. :)
If someone don't know BTTF ... :(
We just celebrated the 30th Anniv. in Cinema and with friends
GREAT SCOTT!!!
Quote from: zoneblue on October 19, 2015, 04:52:07 PM
The AGMs are still going. Now three years old. Next bank will be lithium.
Still trying to "finish" the install. Combiner, SPD, AXS, and tidy up all still sitting in the corner.
This picture gave me a few ideas for my system....thanks!
Hi again
Will there be a way to limit only the charging current?
Lead acid has so many peculiarities to it! I am glad I bypassed them and went with LiFePo4. Simple charging. No input limits. Well, It would take a pretty damn big array to put in 3C for my 48v bank of 100aH. 300 amps incoming. Hmm. That would be fun over a wire, huh?
8)
Quote from: Cniemand on January 20, 2016, 08:25:53 PM
Lead acid has so many peculiarities to it! I am glad I bypassed them ...
8)
Actually, in a fairly balanced system, LA batteries are robust, forgiving and predictable. That is probably why they are still so widely used for more than 150 years.
Am glad that others are adopting other battery technologies ... but there are a number of acceptable ways to store energy.
Am very happy with the LA batteries in use here. FWIW, Vic
Hello, Vic.
Not saying there is anything inherently bad about using Pb. Well. It's had it day for 150 years because that was what was available. However, tech has really advanced since just 2008 with the release of Lithium Prismatics.
IMHO I see Pb cells being nearly entirely phased out for other chemistries that are more "plug and play". Chemistries that do not have typical maintainance issues. Sizing ratios of battery bank aH to PV watts available. Sulphation. Off-gasing. Inability to charge at higher rates. Conversion efficiencies. Temperature compensation/capacity losses.
At this point it is merely a financial point. They simply cost more. Although they make fiscal sense over a long run as most things do in the Solar World. I.E. Hedging bets against runaway energy costs.
I am happy to see the Tesla Giga Factory coming along. It alone should push the drop of Lithium prices to something very affordable. Much akin to China Flooding the market in 2007/8 with Solar cells.
:)
P.S. Wasn't my intent to be boastful or come across as snobbery. Lead Acid works. No doubt. I'm only speaking of good, better, best.
What do we know abou LFP recylclability?
Here is an article on recycling - from 4 years ago .
Sounds like at least at that time it is still a work in progress. But perhaps for larger cells like would be used in solar and the manufacturer and exact chemistry is known that might make it easier to recycle.
http://powerelectronics.com/markets/uncertain-future-recycling-electric-vehicle-batteries
ZoneBLue :
Recycling always falls to an economic interest. When the metals inside a battery are worth it to recycle them and make a profit companies spring up to do just that.
The lithium isn't spent inside a LFP cell. Nor is the Copper and the aluminum.
I suspect we will have very little choice in the upcoming years about recycling. Due to government regulations and the inability to create new landfills. I can also see a time when landfills themselves are re-processed and seen as a place of valuable resources.
Thanks, Larry. The linked article talked about how much recycling is linked to the value of the materials being harvested. Good Stuff.
yes but some things are just so complex that they are too hard to recycle. For instance plastic packging is theoretically recyclable, and yet virtually none is actually able to be cost effectively brought back to the same grade of virgin plastic. Reason? too much junk mixed together, differnt plastic for lid, label, etc. The required microflters are too expensive, and mega tonnes off the stuff is just accumulating in vast piles, or incinerated, or at best used to make playground matting and the like.
Given the complex admixtures in LFP, and the universal reluctance to introduce deposit schemes, i fear something similar? Lead acid OTOH as we know are THE most recycled product class there is.
right, sure, there is allways something better, more efficient, and so on
but just don't solve my (and sure others) situation / problem.
Can not be such a big thing?
System measures the amps going out of the charger
it also measures the amps going thru the WBJr to / from the batteries
and the difference is what needed by load
we have one setting, the maximum amps going out the charger.
we only need a 2nd setting for "max. charge amps". measured from these datas.
At the moment there's a fine line, I have 30 amp set which are at too low consumption partly to high charging current to the batteries.
Actually in the winter time, this is only a short time happening. But back in summer, it can do bad damages to the batteries.
if I set to 23 Amps, this is the max. charge amps, and a load is there, the 23 Amps don't increase. I waste energy.
and so on.
Oh yes the joys of charging lithium house banks at 3C .
Now I just need 10 more classic 150's and a field of PV so I can input the required 1200A! into my 400ah - 48v lithium house bank ;D.
For now I will just have to be content trickle charging the lithium at 160A with the two classics and 8.2kw of PV ;D
Kurt.
Haha. How cool. 8)
Ahh the things that could be done with 8 kW of panels... Panel Envy. (2 kW) :)
A nice feature for charging lithiums would be for the Classic to be able to disable charging if the battery temperature is below freezing ( or close to that ) . I just got some lithiums for a new system. My lead acids I just leave out in the shed and let the Classic temp compensate them. But with lithium I understand it isn't good to charge them below freezing.
Larry
You are right, Larry! A temp compensation to switch off the input entirely on a 32F and below LFP bank would be a useful feature. Although this year, I do not let my cabin interior temps fall that low! :)
Hmmmm.... Well, there is a setting to turn off charging when the Batt Temp goes ABOVE a certain temperature
but now below. Didn't think about Lithiums. Usually you WANT a cold battery to get warmer, but that would be
for a Lead Acid.
These types of things are reasons for adding a separate micro to fine-tune your control I guess...
boB
Usually that is the case, boB :however, LFP cells create little shorts inside the cells when you try to charge them up below freezing. Something to do with how the lithium atoms inter-chelate in the structure.
Yes this is a feature we need to add to both controllers. (Low temperature limit) on the charging. I have asked Mario to look at adding it when you select lithium on setup on the kid.I will talk to Mario about adding it to the Classic as well.
Thank you! :)
Quote from: Halfcrazy on February 01, 2016, 06:15:57 AM
Yes this is a feature we need to add to both controllers. (Low temperature limit) on the charging. I have asked Mario to look at adding it when you select lithium on setup on the kid.I will talk to Mario about adding it to the Classic as well.
Thank you Ryan - That would be great !
Larry
and what about output limit dependent on max charge amps of the batteries?
Actually the Classic JUST last night got Current limit based on WBjr in the code. I will be testing over the next few days to a week and releasing it as Beta
Hi,
some news? ;)
Now I have my Renault Twizy (a small french electric car) and now it would be great, to have a chance to influence (right word?) the output of the Classic.
So I can charge the drive battery a little bit, before I start driving to work.
If sun stands over the house, I have so much energy and can put it in the car.
But in maximum power it can take, this would mean about 50 amps in 48 volt side.
So if the classic must limit the output because the setting, I would lose energy.
(sorry my english is terrible today)
If the classic could meassure the needed energy, it could increase the output, @^# long it is needed.
thanks
Andy
Have now measured the load of the car charger, it sucks 8,2 Amps on AC line (230 V) ("TRMS" with a "clamps" instrument)
... calculating ... this is on 48 Volts ~ 40 Amps
The Classic is limited at 30 Amps (23 Amps for Battery charging maximum + some Amps for the inverter and my home)
So I need a way I can switch between the setting, if it can not do it automatic ...
Changing the setting in the MLP, makes no change effect.
I change the max. Amps from 30 to 40, but nothing happens minutes long.
I repeat change the setting, nothing happens. After a long time, some time, it changes.
That is just not a useful option to do the business with it ...
Any suggestions?
Binkino,
This has to do with the basic way that a computer works. A computer can do only one thing at a time, just because you change a value in a register does not mean that the program will go off and read that register right now. There is a list of things to do in order of importance to the task at hand. The program may wait some time until it needs to read that register again........
I have noticed this behavior in my Classic but it does indeed record that value and does within a reasonable time change operation to that value.....it has never been a problem......we can talk and chew gum....a computer can't
Dave
Edited for iPad's spelling attempts!
Andy,
Don't know of that electric car, I would think of maybe a solar system dedicated to that purpose.
1 kW is a tad bit small to charge an electric car
Dave
Quote from: tecnodave on May 10, 2016, 07:03:34 AM
Andy,
Don't know of that electric car, I would think of maybe a solar system dedicated to that purpose.
1 kW is a tad bit small to charge an electric car
Dave
Hi Dave
it is not a really "car" ... it is classified as a "Quad" or "quadbike".
cheap in insurance an very easy to handle.
You can use it as a daily "car"
The charging power is about 1800-1900 Watts
(measured the Amps ... so I have here ... line: 230V * 8.2A = 1886VA ...
calculating in 48V it is about 40 Amps
(the 48V is system voltage, it is higher while charging and so a bit less Amps, plus the lost in converting the energy, we still don't want to give a notice. viewed over the thumb, it is the needed power)
no problem for my PV, if sun is above the house ;)
My problem still is, that I have to limit the power output in the Classic to 30 Amps because the max. charge Amps for the AGM batteries.
(OPZ are in planing, but are in the future)
There is much more energy I could use.
And build an extra PV ... no, then better charging from grid.
Some days it will be neccessary to recharge a little bit before driving to work, for let's say 30 minutes.
That's enough for a lot extra range.
The Twizy can drive about 80-100 km, and my way is 2 x 38km.
Some days I will have to recharge from grid, some days I want to recharge from PV.
Dependend from weather / sun / ... and how much I have to drive
You can see this fancy car here:
https://www.google.de/search?q=renault+twizy
Renault is still in progress to bring it to the States, labeled as a Nissan:
http://cleantechnica.com/2015/11/02/renault-twizy-comes-to-us-as-nissan-new-mobility-concept/
but limitet to 30 mph Vmax (like the 45km/h Version hiere in Europe, young people can drive - or only need insurance like a scooter)
Has a regular plug ... so you can charge on any wall plug
Andy
The brochure says that Twizy can go 50 mph , 56 miles range , and priced around $10,000 - though the setup they have in England is to rent the battery for it.
https://www.renault.co.uk/vehicles/new-vehicles/twizy.html
Larry
Brochure says Li ion battery but no type......I like the approach taken by BYD LFP prismatic batteries and voltages low enough that a solar controller can charge it.....maybe Renault chose that path
Does anybody know?
Dave
Quote from: tecnodave on May 10, 2016, 09:50:04 AM
Brochure says Li ion battery but no type......I like the approach taken by BYD LFP prismatic batteries and voltages low enough that a solar controller can charge it.....maybe Renault chose that path
Does anybody know?
Dave
I would think that most of those package battery systems will want to use their own provided AC charger system and charging circuits with included protections. So probably stuck with having some inefficiency using an inverter. If it goes 50 mph it probably has a high voltage battery pack.
Larry
It is not possible to charge with another charge, then the build in.
58Volt battery pack afair
I can post more informations in its own topic if there is interest. We have collected a lot infos and pictures of the drive battery in the twizy forum http://www.vectrix-forum.de
There are some users who exermine the kind of communication of the battery and the system, also to build a independend battery pack.
As the battery is rented, some users don't like it and some want their own battety pack.
Also if you once cancel the contract with Renault and you give back the battery, Renault never ever gives you a battety again. You have a brick on wheels then standing in your yard... absolute insane.
But as long as you rent it, you have the right for a working battery, if gets broken or loses capacity <75%
This has not often happened, only the charger of the first rev had problems.
The price of 10.000$ is like here for the 'Technic' version with all extras.
Will you have to pay transport costs extra to the car-price in the US?
Renault now had a discount of 2.000 Euros, so it cost me 7.300,- plus transport of 650,-
Btt: i must charge from AC ;)
No option for fast-charging like in regular electric cars, and no way to charge slower with let's say 500 Watts
I will be building my own electric car, I'm interested in where it's going .
I have one Dihatsu 3 wheel pickup. Like the little Cushman vehicles used in parks, originally 12 hp 2 stroke gas burner. Tiny little cab that 2 can squeeze into, suicide doors, one front wheel with small hood and Austin-Healy bug eye style head lights 3'X 5' bed.....so butt ugly it's cute....candy apple red
Right now has 6 dead worn out GC-8 golf cart batteries ,48 volt, and transplanted golf cart drive. I'm planning CALB or BYD LFP batteries and modern controller charged by Classic
One more project in the works
Dave
let's push this topic once again :D
Quote from: binkino on July 15, 2016, 05:57:54 PM
let's push this topic once again :D
I think Ryan has the Beta output limit firmware he has been trying out -- maybe he will post it - or send him
a message and ask him.
Larry
This feature was added in REV 2096. Attached is the white paper on using it
Hey great!
...have to update (have 2079) :D
I did it short after my post, I believe its working ;)
So just thinking back to this topic, because have to change it; one of these crap batteries I have is dead and had to replace it with an older smaller capacity one for continue working the system. (for the time, till I have a new one)
But you must be very carfell, that you don't change the register number inadvertently while pushing the buttons :D
Allways keep an eye on the display, what the fingers are doing ;)
*remeber the "shift" ting, for faster change the Amps :D
So this is a nice working way.
May be we can get this for easy setting in the next Midnite-App? :D
Just in theory ...
what happens, If I set the max charge amps to 30 and the max amps in the app to 20 amps? :D
Will it override the 30 amps and only charge with 20 amps?
(interesting for my temporary issue with the battery)
Binkino:
Thank you for bumping the topic. I'd lost track of it over the summer. Now I'm reading HalfCrazy's link.
I somehow missed this too .
Will have to upgrade tomorrow.
Larry