Here is the response from Enerdel:
From: Battery Support <support@enerdel.com>
Date: Fri, Jun 17, 2016 at 7:22 AM
Subject: Inquiring on Think City Car
To: “john.mayer@greendropgarage.com” <john.mayer@greendropgarage.com>
Thank you for Inquiry.
We are sorry for your inconvenience, however, we no longer provide
replacement parts for the Think City Car.
However, there are two resources that may be able to assist you.
I’ve included links to their websites below.
http://www.tomwoodthink.com/
or
www.Thinkparts4u.com
Regards,
*[image: EnerDel_logo_Email_signature]*
*Enerdel Battery Support*
batterysupport@enerdel.com
8740 Hague Road, Building #7
Indianapolis, IN 46256
www.enedel.com
Here is the text of the email from me that it was in response to:
Hello Enerdel representatives,
My name is John Mayer, and I’m an automotive technician in Portland, Oregon that services Thinks. I have a Think in the shop now that had some water in the battery. It appears that at least a few transistors on a few different RLECS are ruined. I found a few small cracks where I suspect water was able to enter, and I sealed them up as well as I could. You can find a few photos here:
I have cleaned the RLECs with isopropyl alcohol, soapy water and rinsed with clean water. I baked for a few hours around 200 degrees F. I’m hoping to get them back into the battery pack on Wednesday to find out which ones are still working. (Update: only 1 of the 16 are working.)
So here is what I am hoping to find out:
- Are any RLECs (compatible with the 2011 Think City batteries) available to purchase new? Do you know of any companies or individuals that have bought Think batteries but are not using the RLECs and might want to sell them?
- Can you provide documentation to identify components so that I might attempt to have these boards repaired by replacing the obviously damaged transistors?
Also, can you provide documentation to show which parts of the circuit board are related to which specific function? For example, I have one RLEC (from a different car) that had a temperature value significantly different from all the others (something like moduleFiltTemp_7). If I knew where on the RLEC that circuit was located I might be able to find a bad solder under a microscope. Or replace the components in that circuit. - While I was inspecting the battery cells themselves to make sure no water was sitting between cells, I noticed some heat transfer material (I assume) between the battery cells and the thermistors on the flex/ribbon cable crumbled off. Can you tell me what material I could use to replace that? Would common CPU heat sink paste work?
Can I get some more of the fasteners that secure the RLECs and plastic covers on top of the battery modules? Is there a common part number and supplier from whom I could order them? Sometimes the little center pin part falls down into the battery module and would be too much work to get out. - I don’t suppose Enerdel would want to provide any warranty coverage for water leakage? I have seen 3 occasions (I think) where this has been a problem, and I think the root cause was insufficient sealant applied, usually at the right front corner. (I had to ask.)
- I would like to install some desiccant to batteries that have leaked, just in case my re-seal job isn’t perfect. There is quite a bit of room under the contactors, around the edges of the battery case, and maybe a little bit of room much closer to the RLECs, but I don’t want to disrupt the internal airflow of the battery pack. I can’t imagine that there would be any sort of chemical incompatibility with anything in the pack, but I’d like to hear that from someone who knows for sure. Do you supply any of your batteries with desiccant installed? Can you recommend the best type of desiccant to use? Can you recommend the best locations to install desiccant?
- Also, I was considering a preventative maintenance check for Think owners. I could drill a small hole in the battery (into the empty space below the contactors, with it still installed in the car), apply smoke, and check airflow to see if there are any leaks. If I found any small leaks I could apply sealant externally and apply a slight vacuum to the battery case to try to draw the sealant into the cracks. Then, if there is any sign of water infiltration, I could make a larger hole to install desiccant. Then I would seal it up with a plug and RTV silicon. My concerns here are, again, the desiccant, and also if there might be any negative impact from the smoke (it leaves a very fine coat of oil) on any of the internal battery components. (Currently I leak check batteries with smoke only after I remove the modules– I guess I’ve already smoked some contactors, current sensors, fuses and MLECs… oops.)
- As usual, I would really, really love to have the MLEC source code to see if there might be a way to prevent precharge resistor failure. I know that it’s not Enerdel’s fault that the precharge resistors burn up, but it seems far more likely that a solution to the problem could be found by tweaking contactor closing sequence than with trying to find documentation on the heater from a bankrupt company. In case you are unfamiliar with the precharge resistor problem in the Think City electric vehicles, I’ve attached a few documents with my analysis.
I know that Think has not been the best application to use your very fine product, but please know that there are lots of Think owners out there that really love their cars, and I really want to help keep them on the road. Many thanks,
John Mayer
Attachments:
PrechargeProposal