Haven't tried these myself, but it looks like a possible source for inexpensive A123 LiFePo4 packs.<br><br><a rel="nofollow" target="_blank" href="https://www.bioennopower.com/collections/lifepo4-batteries-for-communication-equipment-ham-radio">https://www.bioennopower.com/collections/lifepo4-batteries-for-communication-equipment-ham-radio</a><br><p><span><br class="yui-cursor"></span></p>