Enginer PHEV automatic over/under voltage protection

Daox

do u have a schematic ? or just a sketch ? i was thinking of using 3 relays, 2 to detect the alarm from the two cellog; as each is at a different voltage reference. The 3rd is rigged to disconnect the charger upon alarm, indefinitely until AC is unplugged.

 

what's the opto isolator part number ? you're right, i just checked jameco.com; it's less than $1 each. but the one i've found has 1.5v input max.

what are the two power source issue ?

 

Daox - you can't connect the cellog (-) alarm pin together, one is at 0v from cell 1 and the other is at 24v from cell 9. You will fry your cellog

 

Daox - your diagram still shows cellogs' CL1- & CL2- pins grounded. I think these are float with respect to the car chassis ground. Their outputs are ok referencing to ground. Since the LTV816 input is rated max of 6v; i guess you're connecting to just the first cell, 3v, of their respective pack ?

I was going to use relays; but I think I'll try these opto to drive my latching relay, a simple DPDT relay.

 

I guess you'll update your diagram later to remove grounding of the two alarm low pins.

This diagram shows auto disabling of the charger, what is your plan to shut down with low cell voltage while driving ? if the arduino is not used during driving, then you don't really need to power it with the 12v ready and can eliminate the two diodes.

 

Where is the dash switch? This shows running off the ready 12v so it implys being on all the time that the car is on. I know that is not what you intend.

Thanks,
Dan

 

Daox - I got word from Jack that he thinks he'll ship the auto charge cut-off upgrade in two weeks, may be you don't need to complete this, unless you want to of course.

 

Hi Doax,
This wearing on the case is no big deal. The plastic case is not the case for the cells. There are 3 round blue sealed cells inside each gray plastic housing. You have a full 1/8 of an inch of gray plastic. So what you are seeing here is trivial. Enginer does install a clear flexible matt on the contact points for the cells, but it looks like they did not do this on the hold-downs. You could add a little bit of rubber sheet material here.

This heating is caused by having some resistance in the connection at the contact point. This is not caused by the cells themselves. The cell contact points are an inch or so away from this contact point and your heating is clearly not coming from the area where the cell is inside the gray plastic housing. This contact resistance can either be from a loose bolt or from a poor weld inside the gray plastic between the stainless molded in nut and the internal leadframe.

Get an infrared heat gun. After you reassemble the pack, run it in the car for a long drive. Stop but leave it on then use the infrared gun to check the temperature of all the connections. A warm connection would need to be tightened. I had a connection point that felt snug but was warm. A little tightening solved the issue. Remember that snug at ambient temperature can become loose when it gets warm and really loose after it gets hot.

You initially had only one hot spot. The second cell started to melt because the heat from the first hotspot traveled down the copper strap. Copper is a really good conductor of heat.

When you put the pack back together put the Copper bar with 4 connections close to the bottom of the box. Put them in in groups of 4. Then after a row of cells is in, put the flexible straps on the top to tie the groups of 4 together. That way the flexible straps will not loosen from handling during installation.

Hope this is helpful.
Dan

 

There it goes for the Mottcell quality.
I would ask for the replacement of the full pack with the newer type.

 

Don't be so fast to blame Mottcell.

There is more chance that this is not Mottcells fault than that it is. The gray case needs to be opened by an experienced person to make the determination.

Enginer has been very good about giving warranty replacements. I am sure that Jack will take care of Doax's needs on this.

But also we all need to be sure that our connections are tight so that things like this do not happen because of contact resistance.


Thanks,
Dan

 

In that last picture it kind of looks like the bolt on the left was not tight all the way. Was the bolt loosened up before taking the picture?