How about the heating matts for greenhouses.... they are designed to have dirty pots of plants put on top of them, and water and all. They seem to limit to about 120F even when sandwiched between foam insulation, and look fairly robust... about 15 watts per square foot, so not too much power.... I'm thinking about doing them for the EV bug conversion when I put the lithium batteries in. It's not a wintertime car anyway -- not having any defrost or heat either, but I'm thinking of days when it's 50's and sunny during the day, but still dropping down into the low 20's at night -- when it would be charging. The BMS will turn the charger off if the battery temp is too cold, but it would be nice to be possible to charge then.
On Fri, Jan 10, 2014 at 1:18 AM, Martin WINLOW <[email protected]> wrote: > This issue is one of the advantages of using an electric (bed-type) > blanket as the fluffy material the heating wires are sandwiched in - in > combination with a flat tray floor and protective, relatively hard layer > between blanket and cell bottoms - avoids point load problems that might > lead to damage to the heating wires. MW > > > On 9 Jan 2014, at 17:53, tomw wrote: > > > Kevin, > > > > If you tape the heaters to bottom side of aluminum sheet like I did, I > think > > it is a good idea to put two or three layers of a tough tape like Kapton > > over the place where the leads are riveted. Over time the weight of the > > batteries may cause those slightly raised riveted leads to punch through > the > > insulating layers on the heater causing a short between them via the > > aluminum. Nothing catastrophic, the fuse will blow, but a pain to pull > the > > batteries to replace it. The somewhat soft insulation underneath the > heater > > helps prevent it too - heaters pressing down into it. You might also > search > > on diyelectriccar on battery heating. Been a lot posted there over the > last > > several years. Some have used the thin film resistive heaters that are > used > > for radiant floor heating for example. You can purchase it by the foot. > > The Farnums are just one option. Taping to an aluminum pan that fits > snugly > > in the box helps spread the heat as well as protect the heaters. > > > > _______________________________________________ > 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) > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140110/b1fef1cf/attachment.htm> _______________________________________________ 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)
