LMS 350 back up battery

[T basser]

My Lowrance LMS 350 does not remain in the last adjustment after being shut down. Lowrance advised me that the internal battery is out and it is not repairable. It is not a big deal but a pain to re program the unit on start up. Any suggestions, I hate things that are not correct. T

[CDave]

Try taking it apart and see what kind of battery it has. Might be able to get one at Radio Shak or at www.batterymart.com

You could rig up a battery back up by getting a 12V battery like is used in deer feeders or rig two 6V "lantern" bateries to 12V and rig a tie in to hook up the battery when the key is off.
All ya need to do is tie into the +&- on the fish finder and hook up a plug to those wires. You could use a trailer light plug to keep from hooking up the wires wrong. Then just plug it in. Ya could also leave it hooked up all the time and use a switch to turn the battery back up on and off.


This battery would work and is rechargable. http://www.batterymart.com/battery.mv?c=ups-apc-backups200

[150aintenuff]

i would imagine the back up is a 3.3 V lithium battery and its not a 12V circut...
opening the unit and figuring out how to replace the backup battery with a larger batery of simalar voltage is only way to protect your unit from damage due to overpowering the backup circuts..