battery backup

IC-7000 repairing - Changing a faulty PA transistor and a failed memory battery to Icom IC-7000

FT-857D Sense Wire Failure - FT-857 show battery icon instead of V, a failure on sense wire cause this.

Battery Bank - Specialize in batteries and batteries charges

Solar panels test - Solar panels test for portable battery charger by YO4HHP

Home Brew 9 Volt Battery Clip - Make your own battery clip by nj2x

Adjustable Regulated Battery Charger - This battery charger circuit is regulated and adjustable to make this circuit able to charge the mosto NiCAD battery.

A NiCAD Battery Charger - A NiCAD Battery Charger with Current and Voltage Limiting

ZL2PD CMOS Keyer - Two cheap CMOS ICs and a few transistors was all that was required to rebuild an elderly TTL automatic morse keyer into a low current lightweight battery powered iambic morse keyer.

Find RFI causes in mobile operations - Troubleshooting your power supply, in determinig connections to battery, alternator and regulator interference and checking power supply leads.