# Lithium ion conversion of Snapper RER mower



## merkurmaniac (Dec 25, 2016)

I decided to make a more generic thread since I have moved on from the idea of using the 56V ego batteries. I'll be dissasembling my mower soon, and taking off all the old gas stuff. I have spec'd out and bought a lot of the pieces for my conversion and I am working on understanding the wiring diagram. 

This is the mower that will be undergoing the conversion. 









This is my rev 0 wiring diagram. I am unsure of the best conventional location for the emergency disconnect switch and also the fuse. I have sketched out the major components and drew the heavier cables as arcs in the attached diagram. Once I get all the pieces into the circuit, it gets pretty complicated. I also realized that where I originally had the contactor, that it would not isolate the motor when charging, so I changed that. Please have a look at the diagram and advise if I am making any gross errors.

Its :


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## merkurmaniac (Dec 25, 2016)

I realize its hard to read: Circuit goes like this,

The yellow thing is a 2016 Chevy Volt Lithium Gen 2 Battery 12s2P 2.3kwh 48V pack.

Then there is a 200amp fuse that I don't know hwere the best palce would be.

Then ED250-1 48V disconnect switch.

then contactor Curtis Albright SW-180-1030L

Mtenergy ME-1004 shunt motor

Then the DC 120V 200A COMBO METER BATTERY CHARGE DISCHARGE INDICATOR WITH SHUNT.

Then, back to the BATTERY.

The thing at the lower right is the connector for the volt/amp meter.


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## merkurmaniac (Dec 25, 2016)

I built this thing this weekend. I was going to use some 2 gage wires that could be bought in custom lengths from eBay. I got the battery mounted on Thursday and decided to find a local place that could make up the cables. I found Texford batteries in Houston, and I could get them that same day. Also, a friend from work gave me his son's leftover giant audio cables from his car stereo stuff. It was 1/0 gage and was massive overkill, I am sure. But, it was free, so why not...

I measured up the cables that I need and headed to Texford. an hour later, I had all the cables in my car on the way home. I wired it up, and was real nervous as I made the final connections. The tractor sprung to life and is running great. For those keeping score at home, it pulls about 20 amps while moving slowly, and about 50 amps with travel and light cutting. Its fairly loud, but is already so much nicer than the gas. Its charging right now in the tool shed. I have to calibrate my meter, so that it can express battery in terms of % charge instead of amp hours. That's to come. I am currently very happy.


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## merkurmaniac (Dec 25, 2016)

Test drive has gone really well. It makes noise, but nothing like before. No big deal to hop off and move a dog toy, then get back on and start it up again. I'll have to keep an eye on what the discharge rate is while mowing the lawn. Swinging the blade takes more juice than just driving around, about double in fact. The current draw is not too bad. 20 amps rolling, 50 amps cutting. I calibrated the meter last night. I'll post a link to it running on youtube when I get a video up.


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## merkurmaniac (Dec 25, 2016)

Here is a pic of my ratproof outdoor cabinet, that is inside my toolshed. This is where the mower will be parked and charged. The drok is running fine. I am charging right now at 1 amp, so thats barely 50 watts. The Alienware Laptop charger is rated at 240 watts, so I am sure it would be fine living at half that rate. I just got my electric mower running Saturday, so this was my first real charge operation. I have mine controlled by my sprinkler system as a zone called "charger" , and this way, I'll not depend entirely on the DROK to keep things between the ditches if I leave it powered all week. My plan is:

1. settle on a charging rate, maybe 1.5 amps.
2. run my battery down next weekend mowing.
3. set the unit to charge for 24 hours.
4. take photos of the voltage each time I walk past my tool shed as it charges.
5. graph it and make a chart.
6. then, when I run the mower later on, I'll bring it into the shed, consult my chart, and see that if its at 44.1 volts, then about 18 hours.. or whatever. Set my sprinkler via phone to 18 hours, and walk away.










The laptop charger has the zip ties. The relay is at upper right. I have since put a bulkhead connector thing on the yellow cable that is exiting at the bottom for the charger to the mower.

I need to shorten wires and cut a small hole in the face so I can read the drok with the enclosure closed. Nothing gets too hot at 1 amp. Dunno about needing an extra fan yet, the weather is nice so far here.


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## merkurmaniac (Dec 25, 2016)

This is my charge connector on my mower. I am using a metal flexible conduit that I trash picked, with two conductor, 18ga wires in it, maybe 16ga. Anyways, its carrying 100 watts or less, so is plenty good sized. The connector and socket are from a place called the Noco shop, and its the 40A YEEDA connector and socket. Nice guys. English is fine, good communication.


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## merkurmaniac (Dec 25, 2016)

I made a youtube video detailing some of the features and a before and after comparison.

https://www.youtube.com/watch?v=28tEvS10e0E&lc=z23gxfzplun4cr3clacdp43ahxoml4ioa30f5ugzlh1w03c010c


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## Mga123 (Oct 21, 2021)

I been following your post just joined this forum is there anyway to do a cheaper version of gas to electric conversion
I have a Snapper Rear Engine Rider w/33” blade I am looking to convert
Any suggestions?


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