navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address. Following continuous spam/hack attempts on the forum, "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: 1 [2] 3 4 5 6   Go Down
  Print  
Author Topic: UPS and Growatt SP2000 unit  (Read 17656 times)
book_woorm
Full Member
***
Offline Offline

Posts: 119


« Reply #15 on: November 13, 2015, 04:42:11 PM »

Turns out the Volt units are not compatible with LiFePO4!!! Just have to keep searching.
Logged

2.4 Kw Kyocera Panels (west facing) Feronius inverter; Sonenkraft Solar Thermal with Twin 180Lt & 280 Lt Thermal Stores; SAP 'A' rated property with UFH & wood burner. Full weather compensation on the UFH buffer temperature & differential controller decides where the heat from the wood burner goes.
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #16 on: November 13, 2015, 05:33:10 PM »

This is the issue I found.

Trouble is the off grid stuff is designed for lead acid and with lithium batteries new to market there's not a lot about for reasonable money.

Also, there's a lot of bad press regarding lithium cells and their volatile nature. I am no battery expert but did read a great deal on lithium battery technology before I took the plunge and convert my standard Prius to a plug in Prius using lithium batteries. There are a few different lithium technologies available of which 2 are mainstream in the ev market.

Limnco2, or lithium cobalt manganese, all ev manufacturers use this tech, high energy density
Lifepo4 lithium ferrous phosphate, Chinese designed, a lot of use in the phev and ev conversions, not much Oem ev usage

Lipo or lithium polymer, very high energy density, not used at all in the ev industry hobby remote control stuff. Very unstable out of its operating parameters.

Most self converted electric vehicles use lifepo4 as they were cheaper to purchase, but as crashed Nissan leafs become available, most ev converts I know through various forums would opt for the leaf packs as they will be cheaper.
I have been using lifepo4 for about 2 years, had no issues with them at all, very stable, don't go out of balance, easy to charge, no profile, just charge to max voltage or your desired max voltage per cell. In my case that would be charge to 3.5 v and discharge to 2.8v, well within the manufacture tolerance of 3.8v and 2.5v.
For this project I will be using a current limiting meanwell 750watt 48 v power supply as a charger,
Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
book_woorm
Full Member
***
Offline Offline

Posts: 119


« Reply #17 on: November 14, 2015, 09:47:10 AM »

Hi, glyndwr1998 - I to have researched the chemistries available. Having seen the sort of ventilation that the GPO used to have for its battery banks and the consequences of a ship fire started by SLA's that weren't sealed! coupled with my neighbours horror stories of lithium ion on aeroplanes (he was an air accident investigator) I'm going to go for LiFePO4. I just hope the prices start to come down.
Logged

2.4 Kw Kyocera Panels (west facing) Feronius inverter; Sonenkraft Solar Thermal with Twin 180Lt & 280 Lt Thermal Stores; SAP 'A' rated property with UFH & wood burner. Full weather compensation on the UFH buffer temperature & differential controller decides where the heat from the wood burner goes.
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #18 on: November 14, 2015, 11:14:14 AM »

Lifepo4 is a good choice, I have been using them for 2 years with no issues.

How many kWh capacity are you looking for, I am on a few ev forums where members sometimes sell on their old packs for upgrades in range.
Most of the horror stories surround the lipo chemistry.

The leaf cells too are very good.

Anthony.


Hi, glyndwr1998 - I to have researched the chemistries available. Having seen the sort of ventilation that the GPO used to have for its battery banks and the consequences of a ship fire started by SLA's that weren't sealed! coupled with my neighbours horror stories of lithium ion on aeroplanes (he was an air accident investigator) I'm going to go for LiFePO4. I just hope the prices start to come down.
Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
book_woorm
Full Member
***
Offline Offline

Posts: 119


« Reply #19 on: November 15, 2015, 12:27:49 PM »

I'm contemplating adding some more panels at the same time as I get battery kit - But being in a National park I need planning permission to modify the roof so that I can put panels where the dormers won't shade them, then there's the wood work as well. A job for the spring I think.

As a mater of interest what can you get a 'Leaf battery' for? and what are its dimensions, the scrap yards around here are not being very helpful. I like the idea of a big battery something around 22KwHrs I believe.
Logged

2.4 Kw Kyocera Panels (west facing) Feronius inverter; Sonenkraft Solar Thermal with Twin 180Lt & 280 Lt Thermal Stores; SAP 'A' rated property with UFH & wood burner. Full weather compensation on the UFH buffer temperature & differential controller decides where the heat from the wood burner goes.
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #20 on: November 15, 2015, 02:12:47 PM »

Hi bookworm,

A Nissan Leaf complete battery is quoted as being 24kwh, with about 22kwh useable.
The pack is split into 3 modules,
Module 1 is 24 cells in a block, 196v max voltage,
Modules 2 and 3 are 12 cells in a block and 98v each.

They can easily be reconfigured using the existing battery buss links.

The apc 10kva ups I have has an input for an external 200v DC battery so maybe module 1 can fit with this type of ups fairly easily.

For a 48v ups system you'd need only 7 cells in series, this is how I have my leaf module configured. 7 cells is about 3,5 kWh and I have 2 in parallel making 14 cells at roughly 7 kWh with a couple of spares.mwith the voltage parameters I want to run to the working capacity would be more to 6 kWh so shorten the depth of discharge and extend battery lifespan.

A complete leaf battery at 24 kWh would fetch 3000 quite easily, and would not hang around long at that price either.

Lifepo4 currently sells for about 1 per ah plus vat in the UK.

I have recently sold a leaf battery complete for similar and could have sold it 5 times over at that.
In a complete state they fill the whole floor pan of a leaf, YouTube shows a good video of a leaf battery tear down that'll give you an idea of individual cell size and whole pack size.

Anthony.
Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
book_woorm
Full Member
***
Offline Offline

Posts: 119


« Reply #21 on: November 16, 2015, 04:35:49 PM »

I'm curious; What is your thinking to use 7 cells for each nominal 48V battery made up from 'leaf' cells, that comes out at 57.1666v? Ok so there are few cells left over once you've made up 6 lots of 7 cell batteries so you can eliminate any that aren't too hot. Am I right in thinking each leaf cell is actually 4 pouches in 2x2 series-parallel or is it parallel-series?

I know the chemistry of LiMnCo2 is different again, but at what voltage are you going to turn the charger off on the charge part of the cycle and at what discharge voltage are you going to shut down the inverter to prevent over discharge?
Logged

2.4 Kw Kyocera Panels (west facing) Feronius inverter; Sonenkraft Solar Thermal with Twin 180Lt & 280 Lt Thermal Stores; SAP 'A' rated property with UFH & wood burner. Full weather compensation on the UFH buffer temperature & differential controller decides where the heat from the wood burner goes.
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #22 on: November 16, 2015, 07:38:01 PM »

Well, I looked on the ev forums at the charge cycle for their 48v lead acid packs and they seem to be charged to 57.5v, of course they will drop back alittle from that setting.

I've set the power supply to 57v, that equates to about 4.1v per cell, the leaf cells are 2 in parallel 2 in series, so one built cell would then be 8.2v, the charger at 57v is alittle less than this.
The cells can go to 8.4v max voltage.

The cut off voltage will be set to 50.5v, that equates to around 3.6v per cell, or 7.2v per built up leaf cell. The lowest r commended voltage for these is 2.5v,or 5v per built up cell, so well within lowest range to save the battery life. Also, the discharge curve drops quite rapidly after 3.5v.

I figured the ups must be ok operating at 57v as that what it is set to charge to, I'm no expert, so I ran a few cycles at these settings and everything worked ok. Had a 6kwh actual capacity with this working voltage range.

So, charge max set point will be 57v

Max discharge set point 50.5v.

I have got hold of a few Peter Perkins type bms slave boards, and a master, that could be used to run and contro the pack, the settings on the slave and master picaxe chips would need to be reprogrammed to work with the leaf cells, but they are in the voltage range so could and should work ok, I haven't any programming experience at all, so it's a massive learning curve for me personally with the bms system, but I do have one full system here that could be used, it's just I'd need to learn how to use it, and to diagnose it if things started to go wrong with it.

At least with the system I will be using its old school voltage, temp and current sensing via relays, I can cope with this ok.

I wish I had someone local who was a hobbyist like me who knew how to program and could show me some basic commands just to get me to learn only what I need to, ie, program voltage and temp parameters in c+ or arduino.
I have 2 complete 16 cell slave boards enough for 2 48 v systems, and 1 master unit, an arduino or duinomite can be used for the second system if I knew what I was doing.

Anthony.
« Last Edit: November 16, 2015, 07:54:02 PM by glyndwr1998 » Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #23 on: November 16, 2015, 07:56:32 PM »

Also, there is a chap on a German photovoltaic forum from Norway that uses I think 2 complete leaf packs in a 7 in series configuration working with a sunny island and that works very well, so I figured if he's using 7 in series successfully then I'll try it too.
Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
roys
Sr. Member
****
Offline Offline

Posts: 439


« Reply #24 on: November 16, 2015, 08:41:54 PM »

Hi glyndwr1998 where about in the world are you roughly speaking, as this sounds an interesting project.
Logged
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #25 on: November 16, 2015, 09:18:31 PM »

Hi Roy's,

South Wales valleys buddy, a small town called Aberdare.

Most of my parts came today, so I can start wiring up the 12v control circuit tomorrow, I'm still waiting on a 12v power supply for the supply to the relays, but I can use a battery for testing purposes.

I'm going to,use a programmable voltmeter with current shunt to measure the pack voltage and current, this has the facility to switch a relay on max and min voltage, current overload too. And visually provides an instant voltage and current delivery form the pack at any time.

I've got 2 programmable temperature controllers that have a relay swtich output to keep an eye on the battery packs

2 junsi celllog 8m devices will keep an eye on individual cell voltages and these can be programmed in various ways, ie, cell max and min settings, pack max and min settings, cell variance between cells, cheap but effective.

I'm hoping to start the wiring of the control circuit tomorrow.

Hi glyndwr1998 where about in the world are you roughly speaking, as this sounds an interesting project.
« Last Edit: November 16, 2015, 11:46:12 PM by glyndwr1998 » Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
book_woorm
Full Member
***
Offline Offline

Posts: 119


« Reply #26 on: November 17, 2015, 09:51:03 AM »

Can you reprogramme the top voltage on the Celllog it appears to only goes up to 43V or are you going to use one over 4 cells and the other over 3 of the pack. Might not work though as I think the cells need to be in serial pairs which would might snooker use on your 7 cell pack even if you can reset the top voltage.

As I'm after something very similar myself 'd like to help, but I'm 150 miles away via the Severn bridge on Dartmoor. I've done quite a bit of Arduino programming in the last few years and I learnt to program many years ago on a LEOII (machine code, 5 hole punched tape etc.). I've found the thing that takes the most time is physically designing and setting up the sensor interfaces to the chip. Lots of issues there of electrical and mechanical security not to mention safety. The software is not too much (for me anyway) provided you don't run out of space on the chip, then you have to start dismantling the code of the libraries to make custom versions that save space. I'm having to do that on the second generation of my differential thermal controller to get the extra functionality in (more channels, better web interface, better download of data log files etc )

Logged

2.4 Kw Kyocera Panels (west facing) Feronius inverter; Sonenkraft Solar Thermal with Twin 180Lt & 280 Lt Thermal Stores; SAP 'A' rated property with UFH & wood burner. Full weather compensation on the UFH buffer temperature & differential controller decides where the heat from the wood burner goes.
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #27 on: November 17, 2015, 10:14:16 AM »

Hi bookworm,

I have been using the cell loggers for over 2 years in the Prius conversion and they work very well.
The have an 8 cell input, so can read any cells up to 8, so 1 cell logger does 7 cells ok, I already have these fitted and working ok for my cycle test runs on the ups.

I'm going to start on the wiring later, and when I'm finished I'll do a video walk through and put it on YouTube, please bear in mind I'm no expert, so the experts out there will probably pick a lot of holes in what I'm doing, so, I'll listen to that advice and maybe revise to revision 2 after the experts cast their eyes over what I am doing.
I think I'll be ok though, got most things covered, I have got something similar already running in the Prius at 265VDC, and just basically copying the control circuit plus additional temp controllers.
There is a small electronic circuit via a breadboard, basically the cell loggers output via a transistor that is very sensitive or weak, so I take that output and onto a breadboard, through a resistor and connect to an opto isolator, this protects the Vella logger and provides total isolation to other circuits.
All wil become clear in the photos and video.

The Peter Perkins BMS was developed over on the battery vehicle society forum and has proven to be very successful and reliable.
I have the 16 cell slave boards, and version 2 master, basically the save boards have a pic 12f683 to each cell to read cell temp and voltage on a slave bus, the data is transmitted from the slaves onto the master bus and passed to the master pcb, this then extrapolates the cell info, has cell parameters set up and balancing circuits to balance the cells at the top end, balance resistors open at 3.6v, max charger cut off 3.8v. These levels are too high for me for lifepo4, I'd rather open the balance at 3.45v and max cell voltage 3.55v.
From running the lifepo4 in the Prius for over a year, the voltage climbs very quickly past around 3.48v.
All this was see signed before the arduino and similar micro controllers became available.
The las
a newer version has been designed on the forum by a chap called Greg fordyse, using a ltm 14 cell chip designed for battery management, his later type also works very well, it is open source, I cell board doing 14 cells costs about 60 in parts, and the controller he used was a duinomite, the later models of this type of platform from olimex use very fast dual and quad core cpu tech like in mobile phones, and can be used as master controllers to comms to slave ic,s via a I2C protocol, which is sadly out of my depth at the moment.
I'm a time served mech eng 50 yrs old, got a degree in mech eng, ok At electrics, and am very keen to learn to program, I'm sure if I sat down with an expert for a day, I'd get the basics enough to get by and learn along the way.
I have got Plc experience via my manufacturing experience and have sat a 2 day Plc course to program and fault find on Plc circuits, so it's not alien to me, and I can learn very quickly, but am much better being shown and examples rather than reading on my own.

I am learning every day on this project and really enjoyed converting the Prius too to a plug in hybrid using 16kwh of Nissan Leaf cells.

Anthony.
Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
glyndwr1998
Full Member
***
Offline Offline

Posts: 104


« Reply #28 on: November 17, 2015, 01:10:03 PM »

The Peter Perkins bms is open source, I have the latest revision of the code in txt and hex format, the same for the master pcb.
With the advancement in technology over the last few years, very powerful micro controllers now exist for little money, a olimexino pcb that has many I/o pins, hdmi out, 4gb on board ram, supports uart has Ethernet, and much much more is around 40 euros, it can operate well as a master controller communicating to a slave via a twisted pair of cables on I2C platform, code is easy (apparently) if you know what your doing, and are very stable.
I just wish I knew how to use them. If they were Plc ladde based based I'd be ok.


I've found the thing that takes the most time is physically designing and setting up the sensor interfaces to the chip. Lots of issues there of electrical and mechanical security not to mention safety. The software is not too much (for me anyway) provided you don't run out of space on the chip, then you have to start dismantling the code of the libraries to make custom versions that save space. I'm having to do that on the second generation of my differential thermal controller to get the extra functionality in (more channels, better web interface, better download of data log files etc )


Logged

7.5kw solar pv
Prius plug in hybrid conversion by myself (now reverted back to standard prius)
Nissan e-NV200 wheelchair converted vehicle
roys
Sr. Member
****
Offline Offline

Posts: 439


« Reply #29 on: November 17, 2015, 04:09:59 PM »

Hi Anthony, pity you are so far away, I am up in Scotland.  I will be following this project with interest though.
PS I have a 300mA selectable voltage up to 12V wall wart transformer if you need it?
« Last Edit: November 17, 2015, 04:38:47 PM by roys » Logged
Pages: 1 [2] 3 4 5 6   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!