Just installed my 2nd user enginer 4 kwh kit.

Well, in the uk we had a big government incentive 2 years ago to install solar, how it works is for every kwh of electricity generated by my solar, the government will pay me 45p, so this is an incettive to install it. It will take 3 years for the government payments for the electricity generated to pay off the installation, but then i get another 22 years worth of payments, it was a no brainer decision to be honest, with bank interest savings rates at all time low, 1%, my solar basically earns me 24%, so apart from me getting to use the electricity i generate, i also get paid to generate it, win win situation. It does get alittle more complicated in a few years time, as the government will install smart meters that will export any unused electricity into the national grid, at this time i will look around for some 2nd user lithium batteries as a storage bank, maybe 6kwh, to use in the night times when the solar has switched off, then an inverter will be needed to up the voltage to 240 ac from the dc batteries.

Solar is very good in the summer, not so good in the winter, but we are in norhern europe here, the sun dont shine a great deal in relation to other countries, but its still a good clean way to self generate. When the price of solar panels fall i will install more of them (but i am at my limit as far as the payments from the government are concerned, a max install of 4kw (16 x 250watt panels).

good luck with your chosen direction, but honestly, if you decided to buy the enginer kit, if it was cheap enough, you will always find a use for the batteries, and maybe sell the converter on the enginer website, theres always someone looking for one.
In my case, my son is disabled and uses an electric wheelchair, so it was in my mind that if the car project didnt work out i could a) use the batteries for solar recovery, b) use them in my sons wheelchair.

Anthony.

 

Enginer and a few other companies are now out of business.

It appears as the US had the biggest growth market, and prius over there are expensive, along with the pure ev vehicles becoming more available at a more affordable cost, then this is how poeple are going, rather than a mod to an existing hybrid.

I myself cannot afford either a new plug in hybrid or new ev vehicle, so this was the best and cheapest way for me, its not for everyone, but i am happy with the path i took.

best regards, Anthony.

 

Ok, that kit looks the same as mine, its a version 5 kit, and probably a version 3.3 bms unit, these are not good units.

You will have a steep learning curve in front of you, and please read loads on these, especially the installation, be safe.
The batteries are Realforce pouch cells of 20aH each pouch, 4 pouches per cell in parallel making each cell 3.2v and 80aH, you have 16 cells in series in 2 blocks, making 48v 80aH. The converter is a 5kw converter, one of the better ones, but still the bottleneck of the system. My converter pushes out 11 amps.

You may want to contact the seller and ask him if the balancing function of the BMS unit is selected to operate in the OFF position, the recommended setting. The BMS still protects the battery from overcharge and overdischarge, its only the auto balancing function is to be set to OFF. This is done by a jumper setting on the pcb inside the case.

On the BMS unit, it does allow charge to the battery at a level that is too high, set to cut off the charger at 3.8v. Unfortunately, this has been known to damage cells, as lifepo4 cells should have a max charge level of 3.65v, that is why poeple try to find alternatives to this bms unit. Even at 3.65v charge level, many beleive that is too high as on the charge profile for the battery chemistry, there is very little energy to be gained much after 3.5v, and this is a much safer setting, protecting the battery and massively extending its life.
My set up uses cell loggers and a pcb relay board, i have another thread here with a wiring diagram and pics of the parts used. basically, a paralle connector is placed in the line of the 9 pin jst cable form the battery that goes into the bms, and the other parallel cpnnection plugs into the cell logger, and the alarm output of the cell logger is set at 3.5v.
Now what happens is that the enginer bms worls as normal, buy my cell log circuit is working alongside, but cuts out the charger before the enginer bms. I did it this way as if i had a problem with the relay pcb or the cell loggers and they failed, my original bms would still cut charging. Just a safety feature really.

On your battery charge level, 2.8v is basically a nearly discharged battery. I have found that theres very little energy left in the battery near to 3v, and although the battery can be taken as low as 2v, theres not much left in it past 2.8v.

As far as balancing is concerned, i balance the cells manually. I have read alot about battery management systems that auto balance, and a few really clever ev experts argue that auto balancing actually may harm the battery rather than protect it.
So, i manually balance as i can control it, and monitor what is happening.
The 9 pin pst connector coming from the battery, the red wire (pin 9) is cell 8 positive, the other end (pin1) is cell 1 negative. Therefore if you placed a voltmeter on pin 1 and 2 you will read 3.2, voltmeter in pin 1 and pin 3 you will read 6.4v and so on until the end where you wil get 25.2v. 3.2 volt per cell. voltmeter in any pair along the string will read 3.2v.
You can view a youtube video of enginer and manual balancing of the batteries and see how its done with a hobby charger.
I discharge the cells with a 50watt headlight bulb, this pulls about 3 amps load out of the cell its connected to, then periodically monitor the cell voltage until it drops to the same voltage as the others. I have found that it is easier and quicker to take charge out of the battery to balance rather than put energy int the battery, but thats just my experience.

If you give me your email address I can send you all the info i have downpoaded (data sheets, install info and installation links to youtube videos detailing the installation, very good they are too, i installed mine myself with little trouble, i am a mech eng though and am used to working with tools and electricity)

best thing to do now is get an energy monitor device and put the pack on charge, and see how many kwh the pack takes, mine takes about 3.5kwh in with my lower set points, and i know i have got 2 batteries that are going high charge early, but its not too much of an issue for me at the moment. Once you see how much energy the pack has taken in, you can then see which cells are high early, indicating which cells need energy draining out of them to balance to get all cells getting the same voltage roughly at the same time (balancing).

I canb try to help you as much as i can, but please take time to read this forum, my threads, and join the enginer forum too, theres loads on there.
Aslo view youtube for enginer, loads there too.

Please be very safe installing the kit, the prius battery at 230vdc will kill you if you are not sure what you are doing.

Best regards, Anthony.

 

Yes batteries are 24v 2 in series.
The smaller 4 pin wires are temperature sensor wires, not adviseable to be used unless your in a very cold climate by all accounts, they are nit used in my packs.
The enginer bms cuts off the power to the charger on the charger dc output side, my cell loggers with a relay in the AC input side cuts off the power.
I`ll email the info i got i found it useful hpe you do too.

The device i use to monitor the kwh input is a device you can buy from walmart or other large store. basically plug in the device into the wall socket, then plug the charger into the device, the device will then read the voltage, amps watts and kwh used during the charge.
I think there is a device in the USA called kill o watt, alot of poeple on forums have used these but i havent personally seen one. Mine only cost about 10 dollars, no money really.

Email coming alittle later today.

Thanks, Anthony.

 

If you check youtube enginer installations, or pis installations, there is a ready signal you can tap into at the prius stock battery where the enginer + and -ve wires are fitted, but i am not too sure what colour wire you tap into. It saves you tapping into the ecu behind the glovebox.
I have just checked and i beleive its the yellow wire I`ll send you some pics via email where it is located shortly.

 

Good to see the install progressing.
Ok points as they are
The switch on the case side of the bms is just the bms on or off. If you run the kit with the bms in the off position then you have no protection at all for the cells they can be overcharged and over discharged as the kit will work with the BMW off.
I sent you a picture of the inside of the bms with the jumper in both on and off positions.

I have been told never never plug or unplug the 9 pin battery just cables into the bms when it is on, if your doing work on the bms always switch it off, but remember to put it back on when your finished.

The cell loggers are cheap £14 here in the uk for non logging ones or £27 for logging ones. Your choice which one to choose. AC relay was £10 and relay pcb's was £13 so quite a cheap mod to do for more protection on the charge side to cut off earlier.

The converter has 2 drilled holes in the top cover, shine a small torch inside thro hole and should see a turn pot under each hole, (if they line up, mine did) the turn pot nearest end is the amps adjustment, the one nearest the bms is the operating voltage adjustment.
They can output 15 amps apparently but then they are working hard and get very hot, not good for electronics. Mine is set to 11.5 amps.
The operating voltage I have adjusted, as when the converter had cut off at voltage high set point, the prius battery state of charge was 60%, I wanted it more to 65% and in the prius battery green zone on the mfd. turned them pot clockwise very slowly over quite a few converter sequences until I got the pint where I was happy. I monitored this with the torque app on my mobile connected to they car via a Bluetooth bod adaptor, works really well but you have a scan gauge so that is good too.
You will need a dc clamp meter to check the output amps are correct and if yu adjust the amps turn pot. I have also slightly modded the case with a fan of a pc to exhaust the hotnairnout of the engineer case when it's running to try to protect the converter from overheating. Heat and electronics is not good, hotter they get the shorter life they last by a general rule.

As my commutes are very short I try to run in ev mode as much as possible as it can get to destination mostly on battery power. Blended mode is better for the kit and you should see 80mpg. I have also got the engine coolant temp hack that works very well, bought it off here, again wasn't expensive maybe $50 or so.

Hope this helps.

 

Did you check that your mains voltage wires coming from the converter to the prius hv battery are connected in the corect place at the hv battery. Firstly, disconnect the converter output cables to the prius hv battery, they are the blue push in connectors, then check that the polarity of the connections are the right way around.
Please view the youtube videos of the installation. I viewed them on a tablet pc and then had the tablet with me during the installation, and referred to them constantly during the install, especially the wiring. If you have reversed the wires you may have caused some permanent damage to the parts.
Check polarity forst then report back

 

Ok, points

Cell loggers are made by junsi, cam ne bought from hobby king. 2 types a cell log 8m no data logging, only display and alarm mode. Ok for most of the time, or
Cell log 8s, data lagging also, it has a USB port where you can plug it into your pc and get a data graph of charge and discharge cycle, useful if trying to fault find the individual cells, although I haven't used that function yet, can do that myself with my eyes and reading the voltage displayed. Maybe buy 2 m models and use all the time and 1 s model to fault find and keep as a spare.
Imams urge clean power auto do a plug and play replacement bms, this will replace your bms entirely and is very good aparantly, it won't work in the up as we are on 240v mains, but is ok in the us as your on 110v, it's about 450 dollars but very good uses cell loggers too.

My converter only has 2 holes drilled, in line from charger side to power exit side. Charger side alters the operating voltage range.

As far as the display device is concerned, I have found it accurate except for the voltage out.
I have checked the amps with a clamp meter to what is displayed and it is quite accurate within 0.2 amps, good enough, although the volts out was reading 220 on the display and voltage was actually more to 235

I have got a Bluetooth OBD adaptor (eBay £12) that plugs into the cars diagnostic socket, and have purchases the torque pro app for the android phone that I have got. There are prius specific files for the torque app that can read the prius battery hv voltage, cell voltages, amps in and out, and and a wholE lot more, along with reading and clearing error codes should they arise.

I had the torque app open and adjusted the converter output voltage up until I got into the green zone on the cars mfd around 65% charge, maybe a little higher, but the app gives actual state of charge not just the bars level, ie 61 or 62 or 63% and so on, very useful.

 

Phew, i am glad it was as simple as the safety plug not in correctly.... great news.

Ok, the bms will shut off the converter at 2.6 volts or thereabouts, and once the load is taken off the cells, they will rest at a higher voltage (as they are no longer under load) similarly, when charging at the top end, the bms will shut the charger off at 3.8v but the cells will rest after about 30 minutes to about 3.8v (this is for a fully charged good battery).

My pack for instance, the bms does shut it off at 2.6v, (sometimes 2.55v), once the bms has shut of the system, the red led is on and a charge is required.

looks like the cells do need a balance, so easiest way is to balance at the bottom, (so i have been told) by draining voltage out of the cells with a bulb or resistor (i use a headlight bulb), drain out the cells all to about 2.8v, thers not much energy in the cels after this point to ist good enough, then charge the pack up and see how much juice gets into the pack, and see which cell actally trups the charger first, and if the other cells are close to it when it trips. If they are all close together, leave alone, or drain some out of the high cell and charge again, and so on so on so on, until your happy with it.

It is not unusual to have slight differences in the cells due to the manufacturing process, and cell internal resistances, as long as you are getting a good amount of juice in to the pack (say over 3kwh) then at least your pack is pretty good, relaly good balancing then may get you closer to around 4kwh.

How new is the pack, has it had alot of use etc,,,, al this will take life out of the cells, but they are quite resilient if you treat them well.

 

Another point about the cell logger devices,

they can be set to alarm also at the low voltage point, i have mine set up to alarm when low at 2.8v per cell. Now the alarm is a bleep rom the device, it is quiet buy i can hear it. At this poinyt i can either manually turn off the dash swtich of the enginer pack, or keep it running until the enginer bms cuts off the pack.

I tend to manually switch off as i want to try to keep well within the battery spec and try to maintain / extend life of the batteries by not taking all the charge.

from what i have read, the batteries have a 2000 cycle life at 80% depth of discharge and you get more cycles if the depth of discharge is lowered maybe about 5000 cycles at 70% depth of dischareg, so by setting at 3.5v on the hich side nd 2.8v on the low side is well within 70% depth of discharge range, hopefully getting me many more years of use.

hope this helps you further