2006 iTech, let the mods / upgrading commence

Hi Jason, I'm not quite sure what signal goes from the EV Works box to the charger to signal it to stop charging and just what triggers that signal. Is it a signal from one of the balance boards across the cells?

T1 Terry

 

Thanks Jason, I wanted to use the EV Works BMS to control the solar charging as well by shutting it off if a cell goes high. Does the balance board array send a voltage signal to the BMS if a cell goes high or low? Or does it just complete the circuit?

T1 Terry

 

Sounds like my next project :lol: I've started stripping down the old traction battery pack. the links between the modules are very corroded and actually require work on the sanding disc to clean them back to copper so I'm guessing this hasn't helped things much. I'll connect all the cells together rather than trying to do them one at a time and charge/discharge them using my hobby charger to see if any of them come good. I tried charging them direct just using an old solar panel and alligator clips but they took less than 1Ah and the module voltage was heading past 8.5v, so I canned that idea.
Have a project for the local Progress Society to light up the "Welcome to Mannum" brick wall type sign using an LED flood light from evilbay the runs at between 32v and 42v. I'm thinking of using these modules to power it if I can get enough to work again and charge them via solar. 5 modules should give me between 30vdc full discharged and 40v full charged so a 3P5S pack should easily power the light all night even if I can only get 4Ah out of each module.
Too many projects, not enough time :lol:

T1 Terry

 

Hi Terry,

Congratulations on your new Prius. Below may be of interest to you.​

Hi Jason and Terry,

Congratulations on selling your car. You can get a Teslanything Product Page | EVolution which allows you to plug your Prius 5 amp charger straight into any Tesla destination charger - Find Us | Tesla which I do frequently. Charging your PHEV or EV at any Tesla destination charger is free. Since I went from Prius to BMW i3 I have become a lot more knowledgeable of public charging. Anyhow maybe it would be of interest to T1 Terry. PlugShare - Find Electric Vehicle Charging Locations Near You

 

We are relative new comers to Mannum so we thought it would be a good idea to give something back to the community in return for the support they have given us as blow in east coasters setting up an unknown business model with next to no business experience.
Unfortunately the wheels of progress grind rather slowly outside the city areas so this has taken more than 12mths to get to the stage of having the box built ready for me to set up the rest. Next will be getting the local council to dig the hole to bury the box and a trench to run the cabling for the solar panel array .... and maybe a wind turbine if I can get that bit sorted.
The issues with getting the whole traffic safety side sorted as well needs to be addressed, just in case someone runs off the road and cleans themselves up claiming the light on the sign distracted them We are planning to mount the box and light on the road end of the brick wall sign so the light does not shine across the road as a safety initiative, but who knows when it comes to how safety people think The council will already be offside because they gave a quote in the tens of thousands to provide the solar lighting and we are doing it for free.

T1 Terry

 

Certainly interested in that. I'm a member of the AEVA and the local chapter and have had informal talks with a few of the govt people involved in setting up the Adelaide electric vehicle charging stations. There was no interest at all in setting up 15 amp single phase outlets at these facilities, mainly because it didn't appear to be a step into the future but rather a retrograde step and they were encouraging people to upgrade to meet the requirements of the newly established stations.
They have a credit/debit card tap and pay system set up on many of the sites, but it was hard to establish if the payment was based on electricity used or time parked at the "bowser" With the present system taking 8 hrs or more to recharge it could end up both time and money expensive, so I think I need to up the charging rate to something both the 40Ah cells can handle and the charging system can supply. Yet another project :lol:

T1 Terry

T1 Terry

 

Hi Terry,

Tesla supply their destination chargers to businesses for free. It's up to the business owner to pay for the installation and electricity costs. Tesla don't mind other EV makes using them despite the sign. Tesla does not own them. These chargers can be found just about everywhere. They are very handy when doing long trips.

 

I bought my charger online at Elcon 6000W HF/PFC LiFePO4 Charger [Elcon 6000W HF/PFC] - $1,620.00 : EV Assemble, LiFePO4, Electric Bike Conversion Kit, EV Charger, BMS, EV Components, EV Parts, All for EV! This charger puts out 105 amps at 48V DC. 6kW. The Tesla destination chargers will supply you 7.2kW using the 32A Teslanything adapter. You would need to install a 32 amp plug on the charger to connect to Teslanything.

 

Is the 32 amps single phase or 3 phase? My battery requires an end of charge voltage of 270vdc, that brings the 7.2kW available down to roughly 25 amps less losses within the charger, so say 20 amps at the worst. 2hrs to fully recharge the 40Ah battery isn't bad at all, finding a charger with that sort of punch might be a bit more difficult.

T1 Terry

 

The Tesla destination charger is three phase 21kW but the Teslanything will only supply one phase 7kW(32amps). When and if you order a charger from EV Assemble, LiFePO4, Electric Bike Conversion Kit, EV Charger, BMS, EV Components, EV Parts, All for EV! you will have to email them all your battery pack information like your lifepo4 battery cell configuration, cell type, make, model, AH etc etc. They then design and make the charger for you. Either way they will email you. That's what I had to do for my Prius using BMSplus. The charger was not available off the shelf. They had to design it and then make it. The price was the same as what is available from the shelf at 6kW.

 

Ok. I remember, now on this page Elcon 6000W HF/PFC LiFePO4 Charger [Elcon 6000W HF/PFC] - $1,620.00 : EV Assemble, LiFePO4, Electric Bike Conversion Kit, EV Charger, BMS, EV Components, EV Parts, All for EV! click "attributes" and then enter all your battery pack details.

 

wow, thankyou for all the info, much appreciated. I checked out the website, filled in the "attributes" calculated shipping to Australia and add the bit the govt wants for doing nothing and it comes out to roughly $3,000, so not too bad at all.
Now to sweet talk the minster for war and finance to allow me to by it :lol:

T1 Terry

 

It would be a good idea to check the Lifepo4 battery datasheet to check that they can take that much charge current. I cannot recollect the details.
76 cells x 3.2v = 243.2volts, current = 6000watts / 243.2volts = 24.67 amps
In any case you have a three wire control cable coming out of the charger which you can use to decrease the charge current using a variable resistor.

 

20 amps is only 0.5CA and that is the base charging current for Winston cells so it should be ok for the GBS cells every so often. The BMS will cut the charge if the cells go high anyway but as long as they are reasonably balanced the 270vdc charge cut is only 3.55v per cell. the balance boards kick in at 3.61v so any high cells should bleed off.

Back to the solar charging. It seems the battery must reach 277vdc for all the balance boards to light up. The 15 semi flexible panels I've used push in 4.4 amps up to around the 255v mark, then the current slowly tapers off. The battery has reached 274.5v and the current is holding at 0.9 amps and all but 3 balance boards have now lit up. Initially the range was between 3.79v and 3.52v, but they are slowly coming together. I disconnect the solar once the 277v is reached until all the red lights go out, then reconnect and each time the difference in the red LED brightness between the boards reduces a bit.
Now I need to figure out just how this linking system between the boards works, at the moment it seems there is no signal until all the red lights come on.
The battery is now holding at 275.6v and 0.8a coming in, the highest cell is now 3.66v and the lowest 3.55v, so it's getting there.

T1 Terry

 

It's a newby mistake to think that this is supposed to happen normally (cell goes over 4 volts). Only happens if you have a bad cell/s or the pack is really unbalanced. When this happens the signal (HVD - high voltage disconnect) is needed to switch off the charger before any damage is done (overcharging a cell/s).

On a good Lifepo4 battery pack this will not happen and the charger will charge right until the end. Each of the 76 cell board LEDs will light up towards the end of the charge to indicate top balancing and hopefully all at about the same time and after a few hours after the charging process has finished each cell should have a resting voltage of about 3.35 volts.