Just installed my 2nd user enginer 4 kwh kit.

I read about the Zephyr years ago, and by the time I got my enginer kit, I am siting there scratching my head what are all these guys thinking?
the cell log is ok I guess, but its just an hvc cut off and lvc alarm, not enough but that is all the stock bms does anyway.
the other route you are going that is $4k, I wonder if you mean BMS only I would not be surprised,
the zephyr I got couple hundred into it an afternoon and a night so far, waiting on some other parts now, I got to rewire the jst balance taps, I don't care for them much
now my question to you is:
if you're going to throw all that cash around, why get a used Enginer kit in the first place, lets see, batteries junk, bms junk, now you need a converter, why you are at it might as well upgrade the charger, hey it came with a nice shiny box didn't it?
I think you are going about it the wrong way, those were ment to be cheap, and I am going to fix it in that manner, building a zephyr is more like legos, testing and trying to understand it is where my ears start bleading, as for the Idea, I only had the Idea to build one and figure out how to make it work in those kits, I am no where near that smart to come up with it, that is that mad man Richard, his design is simply beautifull, still a bit above my paygrade but none of that software upgrade stuff and weird bottom balancing logic, I don't know a lot about the mini's but it sounds a lot like them, and that's how most that done ev's do it, so to me first priority get the pack charged good and go from there.
all that manual balance stuff Anthony likes to do it, I would rather spend the time building a system for it, I would like the wife to be able to use this, rather than having teck support managing the kit
I think you are getting a little too excited and all you are doing right now is throw good money after bad, that is what most Enginer users been doing all this time, I did not want to brag about what I am building until it is done and integrated into the system, and that is the message I was trying to get across to you, hold your horses, this is not going to be fixed overnight, and throwing $ at it does not guarantee it either, let me see if this works first, it wont cost you nothing but time, I had faith if Sush's BMS but if it's that much different you might as well get the whole kit from him, and that defies the point, what your local shop suggest, well that is great and nothing new, pricy too.

 

the car (which i bought only a month ago) had the PHEV kit already installed.
i bought the car cheap, with the full knowledge that the kit was probably not working.

the 4k that i talked about is for...

32x 40AH Calb cells, all interconnects, BMS modules, BMS master unit with 48V contactor, plus a new 25A charger.

the only things i will be keeping are the converter, the box and the switch up front.
as i said, i got the car cheap enough, that im comfortable spending some coin on fixing the PHEV kit's issues.

im kind of re manufacturing it in a fashion that it SHOULD have been when enginer sold them.
with quality components, decent battery management and a nice fast charger.

the 25A charger (it's an active PF corrected unit) draws a maximum of only 6.5A at 240V, and charges at up to 25A
so, in theory i should be able to do a full charge in about 2 hours or so.
less daily, as my normal commute will not completely drain the the pack.

the BMS is a custom designed unit built by a West Australian EV shop.

it's not like i am super rich and just throwing cash about. 4k for me is roughly 12 months worth of regular savings.
i am enjoying the car greatly, and im getting great economy already. even with a kit that will only supply about 700 watt hours before tripping the LVC.

factor in i like my tech and gadgets, and im having a blast with this.

i am really looking forward to seeing what it can do once i have about 3.5kwh useable....

Jason.

 

wait you are still using it as is? Christ man, are you trying to thrash it completely, I bought my kit used and tried it twice before I parked it, no sense beating a dead horse. forgot you bought the car with it on, as for the local shop, don't get me wrong I get it, I am all for good quality locally produced components, hey something breaks warranty or not manufacturer is next door, myself just recently acquired a good used Rfe pack thou I had the kit since spring, and started the Zepher build right away, I think main priority is to get the pack charged right first, and you already had a solution for that, beyond that point the rest of the system should behave, 2.5v lvc is not that horrible, thing that most ppl on here are confused ( I think ) about is that LVC is actually a second degree of protection, just in case something went wrong, and if you hit LVC on any particular cell you might want to have a look at it and replace it,
the problem with this system is that it relies on LVC to terminate discharge, it rags on one cell or another every time,
$5 says that if you charge that new set of batteries with those RC chargers, and if they work like they are supposed to , say you go 90 something % at say 3.55v I bet the converter will terminate discharge long before any of those cells are anywhere near LVC, otherwise you may need to have a better look at the one that got that far down.
that's what I was trying to get across to you, I think you already had the solution before you bought the car, I don't know much about those RC chargers but they might just do the trick, if they can charge and balance the pack with them.
that is exactly why I am building the Zephyr, granted it has all that LVC, HVC, charge throttleing etc and you can program it to whatever your hart desires, but for the most part you got to start with an even pack

 

yeah, im still using it. i figure the cells are already dead. i got nothing to loose now.

once the new cells go in, and are balanced the first time properly, the new BMS will be programed to shut off at 80% dod. should be long before any cell goes LVC. the BMS uses coulomb counting and voltage for SOC calculations, so as you say, the LVC is a second defense layer that should never be reached in normal circumstances.

and, as for the cells i have now. i have data on the SD card that shows some of them way way down at 1.65V per cell.
that's the real deal breaker here. the car was left on the dealers lot for over 90 days with the BMS turned on and connected. with no charging.

so combination of the BMS and the self discharge rates, killed the cells.

don't get me wrong, i see nothing wrong with your approach, it's just that building the zephyr wouldn't be something i could do. i have tried kit building in the past, with little in the way of successes.

so anything i do has to be off the shelf, commercially available stuff.

Jason

 

you'd be surprised, it's really not much to it, in some sense it is no different that what you are doing, you're matching the Calbs, with the bms, and charger, same Idea, you get a board a list of components and instructions where and how they go, I am no stranger to building stuff just electronics is kindof new for me.
That system you speak of yeah sure it's fancy no doubt, bit overkill, but hey, whatever floats your boat right?
bottom line I read through a lot of those threads when I got the kit, and Enginer owners are rather passionate, but with the chance of speaking out of place most have no clue as to how to go about it, I don't think the officials, the ppl behind it had a clue, I am no expert by any means, rather inexperienced actually and I noticed it right away, since when it's ok to rely on HVC/LVC to control the charge discharge cycles, and what are you all doing trying to make it work that way?
bad balancing logic, and what is the solution, turn it off and do it manually every so often, I think they even published a procedure about it, really?!!!!!!!!!!!!!!!!
Anyway, I raging on what has been done is not what I am trying to accomplish, point is it was wrong in the first place and this is not how it's done, so don't rub a wooden leg, you should have seen the replies I was getting on ES as I was asking for advice, wait it does what? and it works how? you're not making any sense you sure you know what you are speaking of? where did you hear that? It just simply did not make any sense to me either, further more they sold this stuff to your average housewife too, what is the idea? let's see how long it takes her to blow it up? chances are that battery pack of yours was toast before it hit the dealer lot, sitting did not help either, guy I got mine from was fixing to trade in for a new prius, dealer wanted nothing to do with it told him to take it all of and come back we'll just pretend this never happened.
the only way I know of going about it is what you just mentioned, the mini BMS, Zepher, I know in Australia there was quite a bit of ev movement and for the most part they all were using individual cell modules with shunts , on the top side, ball parking it is a bad Idea in my honest opinion, let's manually balance them the best we can eyeball it and charge till the first one pops, call it good for 6 months than do it again, if it don't work out we'll just lower the HVC, I don't know about all that. Not for me.
anyway we'll see how I come along this weekend hopefully I got it in me to see this through, if anything my skill, experience and knowledge ( lack of actually ) may be the downfall of this attempt, I'll report here as soon as I figure something out.

 

that is next on my list, as soon as I figure this one out first

 

i did think about the PIS system, but i think ill be happy enough with the reduced fuel use i should see when the kit i have now is operating properly.

if i can regularly get 80-90 mpg in the city, ill be really happy. im already getting 70 mpg now.

Jason

 

I just got done testing my Zephyr, I think I got it, all my shunts come on a 3.56v-3.57v I was aiming for 3.55v, good enough I guess, in theory at the end of charge all my cells will be at this voltage dead even every time, bet none of you ever seen that before, but I'll leave it at that for now, I want to see it work for myself before I start braging about it, just figured to give you all an update, I plan on using the original BMS ( battery monitor system, it's not much use otherwise) too just to monitor the charge and tune the Zephyr, maybe log a few charges, as long as the Zephyr works it will never hit its HVC LVC, I set the Zephyr at 3.57v and 2.7v.

 

i just went to the garage downstairs to hook up the RC charger to the batteries...
i discovered that even though the charger is capable of charging 8S strings,
the charger does not have the correct board to do so..

i only have the one for 2S - 6S strings, so i have ordered the board and ill try it once it arrives.
if i can use the RC chargers, the pack would be fully balanced at what ever cell level i set , every time at the top of the charge.

i still think the packs i have now are beyond salvaging, but for a couple dollars in a new charge board, ill give it a go and see.

with the new BMS and cells i have planned, they will be fully balanced at the top of every charge also.
the cells will have a BMS module that will simply shunt current if a cell get to the high setting first, while the others catch up.

also, it's LVC i will have programed at 80% DOD for cut off. so it should also never see much below 2.8V per cell.

good to hear that you got the zephyr up and running. i am looking forward to hearing how it does.
it should be great. shame it's way beyond my skill level really.
but, i have made my decisions now, and i will stick with them.

Jason.

 

one thing that was sugested to me and I can confirm that can be done, likely what you have there is a couple blocks that are fudged, that's definately the case with mine, each block is made of 4 cells, make them out of 3 instead and you got a good 3 kw pack, now if you allreadyordered and paid for your stuff than stick with it but don't kid yourself the Zephyr is not that hard to build, and one of the designers is still very active on ES and still suports the product a build at a time, it sounds like a lot but you take it one resistor at a time and before you know it you are done.
technically with a properly charged pack one should not see LVC anyway, the converter cuts off at 47v, just shy of 3v per cell, that's why I built one I want all my cells to start even everytime.

 

well, as a consequence of my continued use (or should that be abuse) of the RFE cells, i now have one that is swelled up. so i have now unplugged the kit entirely. the BMS has been turned off and disconnected completely, and the anderson plugs have been unplugged also...

on the positive side, 2 boxes of goodies arrived today










so i now have most of the parts required to re boot this plug in....

32x Calb 40AH cells, cell interconnects and a 25A TCCH charger.

i am still waiting for the BMS and the cell modules to arrive.
it's all coming from the one supplier. he is going to send the BMS and cell modules in a few days via express post.

more updates will follow...

Jason.

 

Calb is going to be way easier to deal with the RFE.
Especially if one ever needs to be replaced.

 

got some goodies myself the other day, charging with the zephyr as we speak, got 2 kw in so far we'll see how it does towards the end there, my original bms is way out of wack, I may need to recalibrate it, I am running it too and I am measuring cells with a volt meter as it goes the bms is not showing the same, also the weirdest thing cell 9 first on the right block, apears the bms is not reading it off it's jst conectors but rather, the #8 positive and second pin on the right jst, I have some improvised wireing that drops voltage by 0.13 v between banks and cell 9 shows it, I will be disecting it after this experiment to see what is happening
so I did open up the bms 16d, sure enough on the right bank pin 1 is floating, it does not go to anything, it measures cell 9 voltage between the pin 9 red on left bank and pin 2 on right bank, due to the wireing there's a .14v difference, big difference if we are talking 2.5v or 2.35v, either why mine could use a calibration and while at it I wonder if done with the existing wireing woulf it actually compensate, but still it's bad enough this unit does not do anything right readings ore off too, I'm sure glad I went this routeand not let it destroy another pack, let's see how long the converter holds up

 

update so far so good nothing blew up. I got about 3.3kwh off the wall, and cells 15/16 allready reached 3.58 v and the zephyr is holding them there pretty good althou the charger is still in CC mode drawing 11 amps off the wall, calculated 15amp out, the charge would have been terminated by now, never reaching CV mode, normally the rest os the pack is still at about 3.41v, they have a way to go, this is why I did not like the original setup, now here's the twist, I had them manually ballanced before I began, on the bottom like most do, but still some cells take charge faster than others and here we are 2 are full and the rest is .2 v behind, that is just simply not acceptable for me, will update shortly as it goes along

 

well just as it aproached 55.5v the charge was terminated, however the pack has a way to go, I am not sure but I believe the zephyr trigered it it does have a charge throttlyng modeif it can not keep up, I tryed plugging it back in through the bms16 d but it would not go, so now the zephyr is on it's own, I bumped the voltage on the charger a bit, it is cycling now, the charger led flashes between red and green, 8 amps fluctuating off the wall, not sure if this is the chargers doing or the zephyr, it was just going into CV mode, amps were droping down to 9v when it reached 55.5v

 

I just got done testing and tuning and completed my first charge with the Zephyr, took a minute even if I had them manually balanced on the low end some got ahead rather fast, the end result it's priceless 3.56v across the board give or take a hundreth, no engineer pack was ever charged this well, 57.1v total, and don't let anyone (even the experts) tell you the charger is not adjustable, I had some help with it, not sure if I should disclose who but the one can is welcome come foreward.
I ended up helping it along the way, drained some cells , charged others, it was handleing itself pretty well the designers thought of everything, I just wanted to help it and speed things up, now everytime I charge it unless I don't alow it to finish it will allways top off to this level so any inconsistencies in the cells will be corrected a little at a time every charge, they should never get that bad out of balance again.
I am banking that the packs will charge discharge rather similarly so the Zephyr won't have to work so hard everytime and after a few cycles it should become more and more consistent.
as far as I am concerned It's the only way if you are going to run lithium, maybe the mini BMS would be another option, I believe they work rather similar , and at the end of the day the build ran me about $200 my tyme well that is a different storry, the end result priceless, just checked the cells #9 and 13 were the last ones to shunt so they were not as saturated they sagged to about 3.5 v most are still at 3.56v that was my chosen HVC, now that is how you charge lithium, see pics

 

congrats

I'm really happy that it's working so well for you. i hope it continues to get better with each charge, no reason it wont...

with my new cells and BMS in place, at the top of charge, all cells will be equal. any that get there first will simply be held there till the others catch up. the BMS modules that go on top of each cell have an 800ma shunt ability.

only thing i wont have is a nice cell by cell display. for that, ill have to resort to a DMM.
key for long and happy life for lithium is rarely charge to 100% and rarely if ever go below 20% on the discharge.
and major differences in cell capacities will really only show themselves at the extreme ends of the charge / discharge cycle.

so keeping them in the mid range should ensure a nicely balanced pack, and a nice long life too.

i should be doing my install in 2 weeks or so.
i am still waiting for the BMS and cell modules to arrive.
my BMS is a distributed one, unlike the zephyr which is centralized.
neither is necessarily better or worse than the other though.

Jason.

 

sounds like you are getting the minibms, I think they do the same thing, the zephyr is rated for 1 A, I had it cooking at almoast 2 and boy did it get hot, that is the thing with those large 80 ah blocks, if you have some at full and the rest at say 80% that meand about 16 ah to go, at 1 amp you'll be at it all day and evening, further more most comercially available units are rated at 70ma-130ma, those will never balance a pack like this, I even stopped the charge and hooked up lightbulbs to some power supply to others to get them closer and speed this up. all this while I had the pack manually balanced on the bottom, like most Enginer users do, in my experience with it bottom balancing is not acurate at all, I had all my cells at 3.21v, display was showing 8% range, however some were way ahead of others as soon as I put a charge on it.
I ran it at first through the enginer bms to zephyr to batteries, the bms16d is acurate at rest but not so much under load or charge, particularily cell 9 I wrote about it earlier it was off by .14 v due to resistance in the wires, with the pack manually balanced on the buttom it actually charged in CC mode almoast all the way, for the last hour cells 15 and 16 were shunting.
here's what I found, when the light on the charger turns green it is not done charging, it is in a slow top off mode, bet you all did not know that, it charged to 55.5v with the led red, for the last volt or so, half hour before it turned green, the amps started dropping, started with about 10.5 off the wall and it satyed pretty steady for 3.5 hous, than it started droping slowly down to 9 amp, that is where I thought it was entering CV mode, as soon as it reached 55.5v and the green light came on the 16D terminated the charge, I tried to restart ti but it just not would not let me do it, so I took it out and charged with the zephyr only manually checking, as I would turn the voltage up either the Zephyr got very hot or started cycling ( a feature it has interups the charge to alow extra time for the shunts to bleed down), so I took it the rest of the way very slowly took all day yesterday, that is whare I was adding bulbs to help the bleed down, PS to charge the low ones, the the idea is that once they are in sink, next charge they will reach the top closer together and the shunts wont have to be on for so long, and it will get more and more consistent.
I was going to use the 16 d for the display but it messes with the charging process in a stupid way it is not just the hvc which it never gets close now, but it cuts charge when the charger goes green, at that point it is still pushing up to a couple amps I seen it, that is the final and most important stage, I may just wire it to monitor the discharge, just plug it into the pack I am thinking to keep the display run the charge through the zephyr directly