Update: Took the batteries out, charged them individually on a noco genus 10, and got them tested at Autozone. Cold cranking amps measured on all 4 batteries: 320, 234, 202...and 30. Well, now I know why its not even turning on. Time to upgrade from the 75AH batteries to the 100ah!
Ryobi RM480E 38" riding mower won't move!
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Barb's 480ex
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Update: The repair manual from Dingo-J is top notch! I followed the troubleshooting guide listed in there and tested these parts in order: the drive selector switch, brake sensor, and the speed switch/transducer. Looks like the speed transducer failed. Just ordered a replacement. I hope that this fixes the issue. If not, the next part to test is the motor control unit.
My RM840e worked perfectly for 4 years as a lawnmower and for pulling a sweeper to remove pine straw prior to mowing at a Tahoe vacation home with a relatively small lawn (<0.5 acres). About a month ago it quit. I drove it out of the garage for about 60 feet and then it stopped before I actually reached the lawn. If I let go of and then depressed the accelerator pedal it would go another 10 feet or so. Repeating this would give me another 3 or 4 feet, then one foot, then 6 inches. My wife helped me push this 700 lb machine back into the garage where I spent several days and long hours trying to discover what was wrong. I dreaded the thought of somehow loading a dead 700 lb machine onto a truck or trailer and hauling it to a distant Ryobi service center, which, by the way, doesn't exist in our area. Home Depot who sold the machine to me denied any responsibility for fixing it. Other HD's in our area said they didn't even sell it except on line.
With help from my brother and a cousin, we reasoned it could simply be a defective switch somewhere or wiring damaged by a gnawing rodent, so we removed most of the cowling to expose suspected components and wires. I also discovered that I could mobilize the mower by pressing down ever so slightly on the accelerator, giving me several dozen feet of movement both forward and reverse until it gave out again. Pulling the PTO switch caused the blades to start but then quickly stopped, within seconds. The fuel gauge (battery meter) read 48 volts and about half capacity as judged by the vertical bars. Two separate calls to Ryobi were not very helpful - one thought that the fuel gauge might be the problem and another sent me the RY48110 Riding Mower Service Trouble shooting guide that I then used to determine that the switches (brake, seat, alarm), lights, fuel gauge, charging port, USB, etc. were good, not the problem. I slid the 75ah battery tray out, disconnected all four batteries, and tested each one individually. Each showed 12+ volts, so I (wrongly) concluded that the batteries were OK. Armchair reasoning lead me to suspect that the only thing that could cause all three motors and controllers to fail at once must be the battery pack. After researching SLA/AGM batteries on line, I purchased a Foxwell BT100 Pro 12 volt automobile battery analyzer (Amazon $36) and discovered that one of the batteries was defective - CCA capacity was about 15% of the other three which read between 350 and 400 amps (despite all 4 reading 12+ volts). I then purchased a Duracel 80 ah deep cycle, group 24 SLA/AGM battery with type C (flat) terminals at Batteries and Bulbs ($216.89), replaced the suspect battery, and now the mower runs better than ever - mowed the lawn without a hitch. Incidentally I found one of the best prices on Amazon: Mighty Max $144.99, free shipping.
The 50% battery meter (fuel gauge) reading was probably correct since three of the batteries were perfectly good and the meter read across all four, not individually. The 48.0 volt reading apparently shows the battery voltage requirement, not the actual voltage. This meter has been a problem for many, as judged from online chats, and there are at least 3 versions of it, one of which can be hacked. The hack didn't work for mine but it has a tiny black button underneath (unreachable) that allows cycling among actual voltage, capacity, and hours mowed. Instead of bolting this meter back in place, I left it out so I could reach a finger underneath to cycle the readings.
Amazon actually sells a similar gauge for $16.40 that looks about the same size as Ryobi's. I haven't tried it but here is the link:
Suggestions for Ryobi:
1) Please fix this meter. Ideally it would read the capacity (load test) of each of the four batteries but at least allow cycling (place the black button on top where it would be reachable).
2) Show real Ryobi riding mower service centers instead of Home Depot and others that deny any training with these machines.
With help from my brother and a cousin, we reasoned it could simply be a defective switch somewhere or wiring damaged by a gnawing rodent, so we removed most of the cowling to expose suspected components and wires. I also discovered that I could mobilize the mower by pressing down ever so slightly on the accelerator, giving me several dozen feet of movement both forward and reverse until it gave out again. Pulling the PTO switch caused the blades to start but then quickly stopped, within seconds. The fuel gauge (battery meter) read 48 volts and about half capacity as judged by the vertical bars. Two separate calls to Ryobi were not very helpful - one thought that the fuel gauge might be the problem and another sent me the RY48110 Riding Mower Service Trouble shooting guide that I then used to determine that the switches (brake, seat, alarm), lights, fuel gauge, charging port, USB, etc. were good, not the problem. I slid the 75ah battery tray out, disconnected all four batteries, and tested each one individually. Each showed 12+ volts, so I (wrongly) concluded that the batteries were OK. Armchair reasoning lead me to suspect that the only thing that could cause all three motors and controllers to fail at once must be the battery pack. After researching SLA/AGM batteries on line, I purchased a Foxwell BT100 Pro 12 volt automobile battery analyzer (Amazon $36) and discovered that one of the batteries was defective - CCA capacity was about 15% of the other three which read between 350 and 400 amps (despite all 4 reading 12+ volts). I then purchased a Duracel 80 ah deep cycle, group 24 SLA/AGM battery with type C (flat) terminals at Batteries and Bulbs ($216.89), replaced the suspect battery, and now the mower runs better than ever - mowed the lawn without a hitch. Incidentally I found one of the best prices on Amazon: Mighty Max $144.99, free shipping.
The 50% battery meter (fuel gauge) reading was probably correct since three of the batteries were perfectly good and the meter read across all four, not individually. The 48.0 volt reading apparently shows the battery voltage requirement, not the actual voltage. This meter has been a problem for many, as judged from online chats, and there are at least 3 versions of it, one of which can be hacked. The hack didn't work for mine but it has a tiny black button underneath (unreachable) that allows cycling among actual voltage, capacity, and hours mowed. Instead of bolting this meter back in place, I left it out so I could reach a finger underneath to cycle the readings.
Amazon actually sells a similar gauge for $16.40 that looks about the same size as Ryobi's. I haven't tried it but here is the link:
Suggestions for Ryobi:
1) Please fix this meter. Ideally it would read the capacity (load test) of each of the four batteries but at least allow cycling (place the black button on top where it would be reachable).
2) Show real Ryobi riding mower service centers instead of Home Depot and others that deny any training with these machines.
dayfamily95
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Anyway you could send me a copy if that manual? Our 2yr old riding mower stopped working yesterday?
Update: New speed transducer installed and we have some progress. Now when I push the accelerator pedal, the mower moves about 50% of the time. Not great. Going to pull the part and test it. Maybe I got a bad one? Then I'll pull the drive controller.
Hi Dingo-J, I understand your repair manual is great, Could you please email me a copy? Thanks, xenomatic
Theotherfuel
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I just had the issue with the blades stopping after a few seconds, turned out that the harness to one of the mower motors got sliced. Also have had the problem with the mower not moving at all, that was the 48 to 12v DC-DC converter.
What is the price on the new batteries?
I would be curious what batteries people are going with. My batteries, or at least one of them, is bad and I'm thinking about upgrading all four of them to the 100 Mhp batteries and wondering if anyone has an Amazon link for what you found and that works.