Daox's Enginer PHEV 4kWh install

Hi Doax,
Glad to here that you have the charger figured out. I think Enginer felt that origionally the chargers were set too high adding to failed cells. I expect that your charger was turned down to make charging safer.

What was your charger set to?

I am sure Jack warned you to be careful in turning the charger up. This setting is the only safety we have if for some reason we do not hear the balancer beep. I beleive that 57v is safe in balanced cells, but I encorage you to check this setting on all of you first 10 or so charging cycles and then maybe once a month or so. If you chould share data on how much "drift" you find, that would be helpful to all of us.

Thanks,
Dan Lander

 

This is really frustrating... I have now typed this 3 times because Priuschat has dumped it.
Anyway here we go again.



Hi Doax,
How well are you balanced? I assume you got some charge into the cells at the lower charger setting.

You are probably OK to use the higher voltage if you watch it like a hawk. You are better to use the lower voltage if you will be in and out of the area or if you may get distracted.


Attached is a SOC chart done by atfsi.

The blue line is his data. The left is volts per cell. The right is charger voltage if all 16 cells are balanced. The bottom is ah of charge into the 39ah cell. The flatened part of the blue line at the top is where the charger has turned off. Then when the cells droop the charger comes on, then off and on for a while. The charger for this data was set close to 58v.
The red lines are added by me. They are what would have happened if the charger was set at 56v and 57v. You see that at 56v you get 22ah of charge and at 57v you get 33ah. This gives you the data for the trade-off decision.
Hope this helps,
Dan

 

Hi Doax,
It is hard to follow your progress on two threads when you do not put all the information on Both. I am a Guest Only on Ecomodder.

Anyway, On Ecomoder you stated.....
The pack is far from charged. Its resting voltage is ~52V right now, charged is 57ish.


A resting votalge of 52v is a pretty well charged pack. There is a lot of historesis in these batteries. It sounds to me like you are in good shape. I would suggest running the car to do a discharge. It should pull the pack down to 46v and then turn the converter off. Listen for Beeps and turn the pack off manually if you hear a beep.

Then charge and balance again.

Thanks,
Dan

 

Daox,
Your experience with the spike in cell voltage is similar to what others have experienced. That voltage spike can occur rapidly, which is why it is important with any basic system like the Enginer system to keep an eye(ear?) on things when charging. When charging, if users simply "Set It and Forget It", I have sometimes seen that the Enginer system may inadvertently allow at least one cell's voltage to jump far above the others.

 

Is this keeping a close eye on the Enginer packs and being actually
physically present when charging necessary just during the initial
balancing/charging phase?

Or is it also the recommended/necessary practice when the system
is being charged after "normal" daily use?

 

Hi Rokeby,
This is dependant on the charger set voltage.

Doax, what was the actual charger voltage while charging the last time you checked it before the beep. What were the 16 cell voltages at that same time?

Thanks,
Dan Lander

 

Hi Doax,
So that puts your charger at 56v (16*3.5v) Is that what you read on the charger with a volt meter?

When you get to work on the car, I suggest that you put a pigtail in with an Anderson plug. Then you can put the box in and out without taking the back seat out again. Look at Atfsi's thread for his 2010 install.


Thanks,
Dan

 

Hi Doax,
So back to the question from Rokeby. If you leave the Charger at 56v, Then your alarms should go away when the pack becomes more balanced over time. That is if the charger was really set at 56v. Reallize that the charger reading is not nessisarily the charger set point. Keep reading the charger voltage everytime you charge. You may see that the set point is a little higher.

However, Even if you stop getting alarms, I would still not trust it for unattended charging. At least not for a while.

Thanks,
Dan Lander

 

Interesting. I have my charger set to 57V for about 1 week now and I have not gotten any over voltage alarms for the past week. My cells are pretty close to being balanced at the bottom. I try to let the system balance out for about 1 hour before charging after every use. I also don't charge all the way through in one cycle. I have a timer that charges for 1 hour and balances for 1 hour. I go thru this cycle about 4 times and on the four time the charger had already cut the voltage off. I have not notice any range difference in my pack but then I am using the buddy system with only 4kWh right now. At the end of the discharge cycle most of my cells are between 3.28 to 3.30V static. Underload, most of the cells have reach some 2.9V at the end of the discharge cycle. Keep in mind I am trying to work towards balance at the bottom (discharged). Most of the dead cells comes from discharging the cells to far in this system. I think atsfi (Jack) and I are trying to balance at the bottom.

As for the pigtail with the anderson plug, that is what I did. But I don't remember requiring the removal of the back seat. I was able to get to the battery terminal quite easily without removing the back seat at all.

 

Hi Banshee08,
I have not seen any data or information to indicate if cells are failing at the top or at the bottom. Clearly we can get both. Do you have data to back up your coment about failing at the bottom or are you just guessing? I would have guessed that most are failing at the top, but I admit that is only a guess.

My understanding is that at the top we see a lot of energy go to heat and then the cell phiscally expands bulging out the sides and leaking. At the bottom the chemical reaction on the plates inside the battery changes the plate so that the chemistry no longer works. Is this correct? If so, we should be able to open a bad cell and see what changed and then extrapolate what happened to cause that change.

Thanks,
Dan

 

Dan,

Actually, my experience with the motocells is that the cells expand and deform as they get stressed and heat up . I have experience two cells that went to .5V during discharged at the same time and I missed the alarm and the rest of the cells in the string started stressing and heating up trying to keep up with the other 2kWh string setup in parrellel. Now I have very weaken cells in my system and has taken me about 3 weeks to id and switch them out. I am luck I have 8kWh of batteries to work with cause I ended up with some 16 bad cells from the episode. This is why I went to the buddy system. That way the converter would stop if more than one cell went dead since the buddy system only has one string of 48V and not two.

I don't have any data just what I have seen so far. The theory in the balance at the bottom is that we like to see if we can get all the varying cell capacity to discharge to 3.1V all at the same time, they should charge to different capacity but as long as we don't go over the 3.6V per cell then it is ok.

I plan to use a 4 cell buddy system once all the replacement cells get to me. That way I have 8kWh all in one string of 48V. I have 2 converters I use and that really helps my highway mpg and systained EV modes (I drive some 30 miles of EV everyday). The way I balanced at the bottom is to put 32 cells in parrallel for about 24 hours, then put 10 amp load on the 32 cells at 3.3V ( in the form of 5 H7 halogen bulbs in parallel) for about 3 to 4 days till all the cells get to about 3.1V. After that I put the cells in the buddy cell format and charge them up, this has worked really well for me but I must admit it takes some real patience.