<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Hi Jay,<div class=""><br class=""></div><div class="">Within the next couple of weeks LiFeBlue Battery will be shipping the new Low temperature models. They have a heater built in and if the cells are below 32°F, charge current is diverted to heat the cells above freezing before transferring full charge current. All handled by the internal BMS. </div><div class=""><br class=""></div><div class="">You can build a box and add a silicone type heater with a temp controller. I\u2019ve bought items like that on eBay for about $25. See photo.<div class=""><br class=""><img apple-inline="yes" id="73E52BF7-B429-4E0A-877A-16E5AEA3BA2C" height="240" width="320" apple-width="yes" apple-height="yes" src="cid:08B995B5-A5C9-48CC-9041-68F2F1809A68" class=""></div><div class=""><br class="webkit-block-placeholder"></div><div class="">Larry Crutcher</div><div class="">Starlight Solar Power Systems</div><br class="">On May 16, 2019, at 4:41 PM, jay <<a href="mailto:jay.peltz@gmail.com" class="">jay.peltz@gmail.com</a>> wrote:<br class=""><br class="">HI All,<br class=""><br class="">I\u201dm wondering if anyone has suggestions about how to charge a Lithium battery in RV or in this case Polarius in sub zero temps.<br class=""><br class="">Are there batteries that have heaters built in, or is it still a custom design issue to build a heating system? <br class="">( insulation and heaters)<br class=""><br class="">Thanks,<br class=""><br class="">jay<br class=""><br class="">peltz power<br class=""><br class=""><br class=""><br class=""></div></body></html>