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On 6/7/2020 at 8:37 AM, PaulNY said:



I have a Ryobi ZT480e that I bought last year. It s a fantastic mower and well worth the price. In the first year I more than paid for it in comparison to what I paid a landscaping company the year before.


Almost from the beginning I have had an issue with the battery. Note: I fully charged it before I used it the first time. I mow once a week and keep the mower plugged in whenever it is not in use. When I get ready to mow, I check the battery level. Since it has been charging all week, it should be at 100%. This isn't the case. The battery will show 70% charge. I discovered if I unplugged it. waited a minute, and then plugged it back in for 10 minutes the battery would then show 100% charge. I called Ryobi about the problem, but their response was that it shouldn't be happening and the representative I spoke with did not believe me. She stated they had never heard of the problem before.


I mow roughly  3 1/2-4 acres. I have to do it with two charges. I will mow in the morning. Plug in the mower for a few hours and then mow in the afternoon. I have been using the battery down to 10% on the morning mow (I now realize I should not do this as I read the article from mycountryacre.com about not taking the battery down to less than 20%).


Anyone else have a similar issue with the batteries or have suggestions? Thanks for your input. 

Hey PaulNY! I'm having the same issue with the 70%. I found my way hear searching if this was an issue anyone else was having. I haven't tried calling Ryobi yet.

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Had seen this from an unreliable source before, but now I think we can safely say it's coming:     Just did a little poking around and can't seem to find much info, I believe that

They stuck a 9 ah Milwaukee under there enough power for a small city ??

Just an update after one year of use.  I mow 8,000 sq. ft. of lawn and occasionally a 16,000 sq. ft. lawn with my RM480e mower.  Electricity cost to recharge the batteries is less than $0.10.  I have

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On 8/29/2020 at 10:53 PM, soonerjim said:

Hey PaulNY! I'm having the same issue with the 70%. I found my way hear searching if this was an issue anyone else was having. I haven't tried calling Ryobi yet.

The instrumentation on the Ryobi’s is known to be variably inaccurate. The ZT480s have been described by many as not reporting the charge % accurately. Some users have even had the meters replaced under warranty with no improvement.  Based on my experience and from working with Ryobi support, the first thing I would do is fully charge the battery pack to when the charging lights on the charger and the mower glow steady green.  Then measure the pack voltage at the bottom two contacts of the charging port.  Voltage should be 51 - 52 volts.  Then turn the key on and turn on the headlights.  Now measure the voltage again.  If it has dropped a lot (the system shuts down when the voltage drops below 36 volts), you likely have a weak or failed battery (I.e. won’t sustain a load).  Ryobi’s procedure is to fully charge all four batteries and put a load test on each to determine if one or more have failed. Many people have replaced all four batteries because they didn’t test them individually. I took mine to a local battery shop for load testing and they found one to be failing. After replacement, the mower runs better than when new.

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Hey, All:


Commenting on several points presented in related posts:

1. I see the same 70% charge on my Ryobi mower if leaving it on the charger for more than 48 hours. If simply charged overnight, it displays 100%. 

2. Regardless of what the display indicates (70% or 100%), I seldom get more than 45 minutes of run-time from it. Sometimes I might get an hour from a "100%" charge, depending on how tall the grass is. 

3. Regarding replacement batteries, I did try replacing the OEM batteries with LiFePO4. A four-pack of those would work great and provide extended run-time, but the mower's controller won't let the machine start with voltage exceeding 52.5V. The LFP battery pack reaches 54.5 after a full charge, but that exceeds the controller specifications and it won't turn on. Similarly, the controller is tuned to turn off the blades at 48v and allow enough remaining power to get the mower back to the barn. However with LFP batteries the controller shuts down the blades AND the drive motors simultaneously. 

4. I get the 'wheel-squeak' that someone posted in a different thread; first from the left-rear (a few months ago) and now from both. I'm not aware of any way to grease or diagnose those drive motors, but I suspect some fault or wear condition is contributing to the very low runtime. 



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USMC Mustang:  Great reply and I have a couple of questions if I may. 

Item #2:  The reduced run time seems to be the most common complaint for the ZT480s.  Have you done the Ryobi recommended battery test of load testing each battery individually?  I was experiencing increased Battery Level Meter bars out on my RM480 in the first year of use.  Ryobi had me individually charge each battery and then load test them (took them to a local battery shop for the test). One didn't past muster and was replaced.  Mower ran (and still runs) better than new. 

Item#3:  I'm extremely interested in the lithium batteries you used.  I've heard several people wanting to try the change, but you are the first I've heard of to do so.  What make, model, voltage, ahr, etc.  I have seen my OEM pack at 52.2 volts immediately after completing a charge, and it ran fine.  Ryobi also told me the system shuts down completely when the pack voltage drops below 36 volts, but I'm not sure how the system is really measuring things as the BLM does not read reliably by volts, so the controllers must be measuring something in addition.  The system is supposed to shut the blade motors off with enough charge to let you drive back to the charger.  I run with a separate volt meter plugged into the charging port so I can see dynamically the charge being used.  I would guess the lithium chemistry behaves differently enough to "fool" the electronics that are designed for the SLA/AGM chemistry.  How did you charge the lithium batteries?  With the Ryobi charger and onboard controller, or a separate charger?

Item #4:  First I've heard of the squeaky rear bearings on a ZT480, best advice is to call Ryobi at the toll free number on the label under the seat with the model number, serial number, and manufacturer number from the label also.  I wonder if it's the brakes?


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