View Full Version : Semi OT - charger for my lawn robotic mower!

03-17-2006, 10:26 PM
Why is it not suprising that somebody into RC would have a robotic lawn mower? I've had a Friendly Robotics Robomower (http://www.friendlyrobotics.com/) for 1.5 years now. Does great work, too! Like they say, smart enough to mow your lawn, domb enough to do it for free! :)

So I have two battery packs for it and you have to use the mower's charge jack to charge the battery. They take a long time to charge, so I can't be charging two at the same time or charge one while the unit is out working.

They have an external charger you can purchase....most places sell it for about $135!!! (http://www.probotics.com/detail.asp?num=27) (http://www.probotics.com/detail.asp?num=27)

However, today I opened the battery case to inspect. Now that I know a little about elctronics/batteries (I've been flying electric now for just over a year) to be VERY DANGEROUS. :) Here's what I found...2 batteries inside the case, wired in a series. They are Toyo 6FMH18 batteries (says 12v/20AH). On the side of the case with the terminals that connect to the mower is another plug - looks like a charging plug (and is wired into the system) -- but even the external charger uses the jacks that the mower connects too. Hmmm...

Anyway, I'm thinking there is probably a cheaper an easier way to charge these things than $140 + s/h. Just a matter of a little elctric know-how and the right equipment. Here are all the battery specs:

Anybody have nay ideas to get me started? I'm electicly dumb. Pretty mcuh all I know is from RC stuff, and that may be a broad knowledge, but it sure is shallow.


PS. Of course, I also thought...I wonder if I can get LiPo's in there?...but then I thought about the cost ($$$...the stock batteries are about $35/each anyway -- and you need two for a pack) to get the capacity needed. EEK. Lipo's would be outragous.