R.i.p. 2kw enginer kit

sorry to hear it. you missionaries should be getting free service and parts, not the cold shoulder.

 

My story is simular to yours , sadly. Except I am going to lose way more I fear. I have two 8 KWH systems, bought in 2009 and 2010 respectivly and my 2009 system batteries are quite weak now(they will EV only 10 miles on 8 KWH kit!) after way less than 1000 charges and only 50-60% DOD when discharged. I have had to replace: 9 converters, 7 balancers/BMS, 12 chargers, 12 Mottcells and 1 50 amp breaker. I am not complaining about the hundreds of hours of my labor diagnosing and replacing bad parts, i knew that was part of it when i bought the kits and in the first year, Jack responded most of the time, eventually, but my systems/kits sometimes sat for MONTHS without working, waiting for parts. Now when i contact Enginer/Jack, i get the TOTAL cold shoulder and no calls back at all - EVER. I guess the several thousand i spent, did not make them enough to continue customer support(if any customer support at all). They even have a "service center/installer" for Enginer in Minnesota (biggest in the USA i think), But they will not even exchange new for old parts with me, even if they have the replacement parts there, unless i bought the systems from them, not Jack/Enginer itself/himself. If i get any parts exchange at all now, i have to pack then ship the parts to Michigan, pay the shipping and wait and wait. As an early adopter/customer who ventured into this on some faith like me, i really feel burned, to say the least. The latest was last month, my BMS16C failed(did not stop the charging!) and charged my system way way too high. I have damged cells from this and i contacted enginer. I finally got a response, after several weeks and emails and was told to ship all bad cells back to them and they would send out replacement cells. Oh great i FINALLY got a response. But who is paying the $300.00 or more on shipping to send all the bad cells back that there failed part(BMS16C) damaged. Mmmm, i think i am, OUCH! Of course, i could just drop them off at the Minneapolis installer/Enginer seller, but when i asked this, i got no response. Of course when i asked Enginer to cover the shipping of the bad cells back to Michigan, i got no reponse either...I hate when the truth hurts!

 

I've looked a pics of the cooling in the system and it doesn't look up to the task, IMO. Can anyone comment by first hand experience if cooling is the issue on the component failures?

 

I've worked on some large scale EVs and the Enginer system is a complete joke.

The DOD cannot be controlled well because the converters and BMS are so inaccurate. With LiFePO4 cells, being off by a hundred millivolts is a considerable error with the state of charge. So if you think you are driving until dead at 50%, you may be going down to 20% or worse. Also charging you might be getting them up to 90% or even high 90's instead of keeping it down around 75-85. Both of these derate battery life.

Look at slide 2: http://www.thunder-sky.com/pdf/201072311158.pdf

You will see there is 200mV difference between fully charged and 20% charged. The BMS system in Enginer systems is so wonky that you will have no idea where the SOC is. 80% discharge gives 3000cycles and 70% gives 5000cycles. This is if they are all balanced, charged, and maintained accurately. Again the system is so wonky you are going to have misbalanced cells to begin with.

It is a nice toy, but that's all.

I might be interested in buying your batteries. The rest I could care less about. I need a set to do some Prius PHEV experiments. I am building my own system and am at the point where I need some real capacity cells.

 

I might be interested in your converter and maybe your charger too.

I'm considering purchasing four of the optima yellow-top D51 batteries and hooking them in series in addition to/in place of the Thundersky cells I have. I understand that even though they are deep-cycle batteries they won't last as long as the (advertized) life of the Thundersky cells. But it seems those aren't really that robust anyway. Weight per battery is 26 lbs, so it will be adding ~100 lbs to the unit. If it works well, I might remove the Thundersky cells to lighten the load.

Main issue will be installing them securely and venting them. They have vent plugs so I should be able to hook some tubing together and run that outside. If I run the charger to the D51s (through the circuit breaker of course) and then run the leads from the batteries into the converter I think it would work the same as the Thunderskys, with any luck, having a greater capacity as well. I would also need to run some kind of voltmeter rig up to the front so I can monitor them.

See any holes in that idea??

 

I thought the problem would be related to the cheap(ness) of the LifePo4 cell manufacturing. As is low quality.
Not the electronics to the millivolt level affecting SOC to that level. Incredible.

Also incredible is building a business on what is a great engineering concept, in essence as simple as possible, for a PHEV system, to have such complicated shortcomings like charging.

Makes me appreciate full EV's such as the LEAF even more. Might make me consider keeping my hybrid a hybrid, and getting a full EV as a 2nd car (instead of the current 'cheap' Hyundai Accent my SO uses to/from work).

IOW, the subtleties of PHEV systems blow me away.

From all these PHEV posts and DIY systems I've read on PC for the last 5 years, it seems the best system would be to double the current NiMH Toyota HV battery, installed in parallel.
With perhaps a shunt/charge system for the 2nd battery. Or not, since I do some highway speed driving to work. Best bang for the buck?

I really wish Enginer's system the best, as it's my current favorite PHEV option. Pun Intended.

 

For the price of 4 Optima D51 (~$640), you are almost at the going rate for 16 40ah cells from CALB or Hipower (~$850), for 1/2 the weight.

 

Why would I expect any better performance from them vs the erratic Thundersky cells I have now? Do you have any experience with them? Granted, the problem with the Thundersky may be BMS related rather than the cells themselves. In that case, again, why should I expect any better performance?

 

kammssss,
Sorry to hear of your latest issues. If you have the ability to record data about the batteries as you drive, I would be interested in seeing it so as to see what's up with battery condition. I have seen cases where a single cell is affecting how many kwh can be charged. Any idea how much you are able to get into the pack? An individual cell balance can often take care of the situation.

As far as not hearing from Enginer. They have said that they are quite busy and a bit shortstaffed. Plus the rising gas prices probably contributing to more interest. I have experienced weeks delays at times before hearing back, but eventually I get what I need. (parts, etc.) Feel free to contact me if you have any questions or leave a time and number to call and I'll give you a ring.

 

I really hope you mean you will use the extra converter just to boost the 12v's up and tie them in parallel on the output (OEM HV battery) side...

Otherwise, NO!

The charge cycles for the two chemistries are completely incompatible as well as the resting voltages.

The batteries they are using work just fine when they are used correctly. When abused as they are, the life you got, is the life you should expect. I am not saying this abuse is your fault, it is the fault of the poor quality chargers, and BMS inplace.

It is a good concept, and it can work well. But there is a reason why people pay premium dollar for a good BMS system. With something as picky as lithium, it better be good or it is thousands of dollars wasted.

Anyways, it seems like you have an interested party in the batteries (me) and the charge/converters (mj frog), so will you part it out or just sell the whole thing on fleebay?

 

Yes, absolutely. I plan to connect the D51s in series (output is ~52v), then run them into the second converter which would run either in parallel with the existing converter, or I would shutdown/remove the old batteries and converter.

The reason for using the D51s is because of all the BMS problems and getting/keeping the Thundersky cells balanced. I figure the D51s would be more robust and simpler to manage.

 

Ok cool. Doesn't sound like this will be as exothermically exciting like what I thought you were doing.

The Enginer system should be more than capable of managing those cells. They are much more forgiving. If you use restraint and follow the same advice of not running them into the ground after every charge, they should last a while.

 

Okay, there are a few different routes that you could take.

1. 4s 12V Optima running a second converter that you have added to your system. Converter low-voltage shutoff will protect against overdischarge. Run at a lower current than the other converter to get more life out of the Optimas. Need a 48V PbA charger.

2. 16s Calb/Hipower running a second converter. Make second converter primary, and existing converter secondary/lower current, to extend the life of the aging Thunderskys. Must have second charger and BMS.

3. Replace 16s Thundersky with 16s Calb/Hipower, after resolving BMS issues.

I don't think you can safely run a string of 8s2p Thundersky and 8s2p Calb/Hipower due to slightly different charging/operating voltages.

I have no direct experience with Calb or Hipower but reviews are favorable and one or the other will be going into my EV project. My experience with LiFePO4 in general is that a properly functioning BMS is critical. Solve that issue before making any changes!

 

The understanding of how to maintain the batteries is critical. Relying solely on a BMS gives a very false sense of security. I have a 8kWh kit in my 2010 prius and have been using the setup without any BMS for about 14 months now with 2 charges daily and my pack can still net me about 100 miles of blended driving if I push it. I don't see much depletion of capacity but I monitor my battery voltages very carefully after charging and after discharging. My pack stays very well balance since my initial bottom balance over a year ago.

Most of the problem is that this kit is not very plug and play due to faulty components. The individuals using the miniBMS maybe onto the road of plug and play as far as battery preservation.

 

miniBMS seems to be doing a good job with my pack. brought it back into balance quickly, and it is remaining there. It's inexpensive, and very simple.

 

I am in the process of having a 4kw system installed in my Prius and was wondering what the minibms is and where can I get one? Also how difficult will it be to install?

 

It is a bit more challenging than original system since you will need to do some modifications to integrate it. An additional 3-5 hours of labor plus parts and time to source the parts. Depends on how technically inclined you are. Actual BMS is ~$250.

Are you doing the install yourself or hiring someone?

 

I am having system installed by local enginer dealer. But a friend of mine is
very tech savvy and he will be assisting in any mods that will be required to make system more reliable.

 

Well, if the labor is free, that'll help you on cost. The additional parts needed are reasonable.