Please use only the Grace Digital Lithium Ion proprietary battery back in the Mondo+ in order to not void your warranty. We have been informed by numerous customers that the cheaper blue non-authorized lithium Ion battery sold mainly on Amazon may cause issues when used in the Mondo and Mondo Plus (+). Issues may include the radio often re-booting, freeze, or overheating or not powering on at all while connected to AC power. (We have attempted to contacted the non-authorized 3rd party manufacturer to tell them of the issue but they have not responded back.)
To purchase the official Mondo+ battery please go to the following link: https://gracedigital.com/shop/mondo-battery-pack
We are happy to offer a coupon code to you if you would like a battery for your Mondo or Mondo+, just ask! Our San Diego based customer care team is available by telephone at 866-446-0961 M-Th 9 AM-4 PM and Fridays 9 AM-Noon Pacific. or via email at firstname.lastname@example.org.