Semi OT - charger for my lawn robotic mower!
#1

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)
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:
http://toyobattery.com/images/6FMH18.gif
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.
Thanks,
Ryan
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.

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)
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.

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:
http://toyobattery.com/images/6FMH18.gif
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.
Thanks,
Ryan
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.
#2
New Member
Join Date: Nov 2020
Posts: 2

Robotic Lawnmowers are the best mulching mowers, they do not collect the grass but instead, cut it into fine clippings and scatter them to decompose so the nutrients go back into the soil. although keeping the perks of the Robotic aside, Replacement batteries are expensive and must be a hole in your pocket. most of all the riding mowers equipped with 12-volt batteries, some of the models that are built before 1980 use a 6-volt battery. it is advised to Use a charger that matches the voltage for your battery. Also, use a charger with an output of 10 amps or less. Charging a battery with more than 10 amps can damage it.
Last edited by firemanbill; 02-05-2021 at 04:18 PM. Reason: deleted link
#3
Super Contributor
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,908

I cannot get any link to work .... so we need more info ...
There is literally no battery that an RC Programmable LiPo charger cannot charge .... within reason. The trick is to understand what composition of battery ( LiFe, LiIon , LiPO, Laed Acid etc) total voltage, charged capacity, number of cells etc.
There is literally no battery that an RC Programmable LiPo charger cannot charge .... within reason. The trick is to understand what composition of battery ( LiFe, LiIon , LiPO, Laed Acid etc) total voltage, charged capacity, number of cells etc.