Dan, You should check the instructions for the laser thermometer - I expect that, like mine, it recommends a maximum reading distance (from object of interest to instrument) in single figure inches! MW
On 15 Aug 2014, at 02:32, Michael Ross via EV wrote: > I am with Jan. > > The laser thermometers are averaging over the whole patch you see lit up > and they are not hugely accurate because of it. If the patch is larger > from being farther away or not circular because it is on an angle - it will > not report what you are hoping for. They are best for shining inside a > uniform container, oven, furnace, etc. Or if at a wall, then you need to > take a series of readings. > > Imagine on one terminal you slide off to one side and average in some > temperature from the top of the battery case. Or you have to get very > close to one and far from another, and so on. > > Can you share what make and model of thermometer you are using? > > Mike > > > On Thu, Aug 14, 2014 at 7:21 PM, David Nelson via EV <[email protected]> > wrote: > >> If this is a change then I would investigate. I have had my pack in >> for over 4 years and have not had the issue you and others have had >> and my pack isn't exactly closed to moisture and dust. I have 40 >> TS-LFP100AHA cells in a 2p20s arrangement. Because the BMS I used to >> use attached to the heads of the terminal bolts I used brass bolts >> since they are much easier to drill and tap threads in. This also >> meant that I could assemble the pack and torque the bolts independent >> of the BMS connections so they could not interfere with any >> connections. Before assembling my pack I wire brushed all the >> terminals to shine them up. I did this with NOALOX on the terminals >> and SS wire brush so that the NOALOX would seal the metal as soon as >> possible. I also tapped all the terminal holes again, using NOALOX on >> the tap though this was probably way overkill. I did find some >> terminals that didn't get tapped all the way down. I then put NOALOX >> on the bolt threads before assembling. This was mostly so that the >> soft Al and Cu terminals wouldn't gall up at all. I used bronze lock >> washers, too. I have had no terminals come loose or get warm. >> >> Some may say that what I did was a waste of time but they can't >> counter the results. It just works and I'm glad. LiFePO4 has been much >> simpler than lead acid in many ways. If I were you I would clean all >> the terminals using a similar process. If I were to do it over, and I >> have on small 4-8 cell packs, I would use NO-OX-ID "A SPECIAL" because >> it doesn't seem to get sticky over time like the NOALOX does. >> >> On Wed, Aug 13, 2014 at 2:20 PM, Danpatgal via EV <[email protected]> >> wrote: >>> I am using 38x130 ah CALBs in my Lectric Leopard and have had a too hot >> (> >>> 40C) warning on my BMS come on a few times in the last month or so. >> Today, >>> after a longer stretch of accelerating uphill to home, I checked some of >> the >>> battery posts. Measuring with a laser sensor, several of them were >> around >>> 33C , in a grouping, maybe 6 or 8 posts adjacent on the most positive >> side >>> of my pack. Posts just a few cells more negative were much cooler, maybe >>> around 26C or cooler. >>> >>> I checked the bolts to make sure they were tight, and didn't notice any >> real >>> problem with the connections being loose. My only other thought is that >>> perhaps (as has been discussed in other threads), these connections have >>> corroded over time ... adding a little resistance layer (I didn't >> initially >>> polish or use Noalox on those) that is now finally heating up. I am also >>> using the original copper straps with steels M8 bolts. >>> >>> Are others noticing this kind of heat with the lithium cell terminals? >>> Aside from just cleaning the terminals and putting on some Noalox, might >>> there be other things to do? I installed these in Sep. 2012, so they are >>> not quite two years in service. >>> >>> Thanks - Dan >>> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
