Ryobi battery riding lawn mower

[David Bacon]

I have the 75ah RM480e and notice that when it gets to a low charge (about 1/3 left on the battery indicator) the blades will stop. It will sometimes begin backing up at the same time if my foot is still on the accelerator. Is this normal or is this an issue to addres?

 

Also, I plan on checking the batteries, but was wondering if the controller prevents the mower from ever getting below a certain percentage, shouldn't I be able to keep mowing even when the indicator is way down at nearly empty, not with a 1/3 left? I have a 1/2 acre to mow and for the past two years could mow it all no issue, but this year, I get only about 90% done before the blades stop.

[jamis]

The system is designed to shut the mower down when the pack voltage reaches 36 volts.  This is to keep the routine depth of Discharge (DOD) at 30% or less.  This maximizes the number of charge cycles the batteries can deliver (1,500-1,700).  The BLM is notoriously inaccurate and Ryobi won't say how it works, so measuring the pack voltage may be the only way to see what is going on.  I had one of the batteries fail at 11 months to be able to hold a charge under load. Run time had been degrading shortly before failing. Ryobi said to pull the battery tray, disconnect the battery wiring, individually charge the batteries, and load test each.  I took mine to a local battery shop for the load testing.  I would bet measuring the pack voltage when the deck motors shut down would be a first step at showing a failing battery. I measure pack voltage at the beginning of each use and at the end just before plugging the mower into the charger.  You can measure the pack voltage using the bottom two contacts in the charging port with a volt meter.  Voltage right after finishing a charge cycle should be north of 52 volts.  I use a watt meter ($30) to record charge cycles and can see if the system is holding a charge between uses.

[jamis]

I can't explain the sudden backing up issue.  Are you sure you didn't hit the F-N-R switch by accident reaching for the deck motor switch?  Did the mower beep when the deck motors shut down?  The system can be a bit flakey.  I recently ran my 34 month old RM480e down to a flashing red bar and a solid red bar while mowing.  No beeping and the deck motors kept running.  I shut the deck motors off and drove the 500+ feet back to the charger.  The pack voltage was 47.2 volts.  I simply don't trust the factory instrumentation and record usage with a spreadsheet.

[David Bacon]

12 minutes ago, jamis said:

I can't explain the sudden backing up issue.  Are you sure you didn't hit the F-N-R switch by accident reaching for the deck motor switch?  Did the mower beep when the deck motors shut down?  The system can be a bit flakey.  I recently ran my 34 month old RM480e down to a flashing red bar and a solid red bar while mowing.  No beeping and the deck motors kept running.  I shut the deck motors off and drove the 500+ feet back to the charger.  The pack voltage was 47.2 volts.  I simply don't trust the factory instrumentation and record usage with a spreadsheet.

Yes, the mower beeps when the deck shuts down, it lurches to a stop and then begins to back up if I keep my foot on the accelerator and continues beeping as it does in reverse mode. I have learned to let off the accelerator and press on the brake when the deck motors stop. I know I haven't accidentally pressed the button because this happened more than once and it happens when I am still steering with both hands.

[Dawn]

I have a Ryobi RY48110 that I bought May 2019.  When I began using it this spring I noticed the AuxPower would not register.  I also have 1/2 the original battery life.  Any thoughts on why this occurred?  I brought it in to an authorized service center to have it "repaired".  I honestly think they didn't do anything to it.  Of course they only warranty the  battery for 1 year.  I'd appreciate any insights to help me repair this problem.

[jamis]

AFAIK, the AUX position of the key switch has never worked on these mowers. According to the troubleshooting manual and my mower, there is nothing connected to the AUX lug on the bottom of the switch.  Run time is  going to be affected by the ability of all of the batteries to hold a charge under load.  It only takes one of the four batteries to bring the system down.  Since the system shuts down when the pack voltage drops to 36 volts, if one battery fails to hold a charge under load, you can see reduced run times.  Therefore, measuring the voltage at the beginning and the end of any usage will help you understand what's going on.  My 34 month old batteries can sit for a week or more without needing a maintenance charge this summer, but they will still mow for over an hour and a half before getting into the red zone.  My batteries have 195 charge cycles on them also.  It's really too bad Ryobi decided not to utilize the voltage and percentage functions of the BLM.  The information would be most useful for owners.

[jamis]

I was just reviewing the Ryobi Troubleshooting manual for these mowers and there is nothing in the manual concerning testing the battery pack.  The procedures start with testing the main fuse and continues on through the remainder of the system and its components.  I have no idea why (and I don't expect Ryobi to explain it) the battery pack is left out of the process, but over the years, the preponderance of problems reported publicly have been with reduced run times and there is nothing in the manual to address it.  Probably why the service centers don't know what to do with it.  There are four RM480s on my street of 16 homes with a fifth coming and the nearby (1.5 miles) service center hasn't touched one since they came out in 2017. A failing battery can fully charge and then quickly discharge under load and cause reduced run times until it fails completely and leaves the mower immobile.  Anyway, the first step to do if your run time has degraded is the following:

1. Pull the battery tray per the steps outlined in the owner's manual and don't forget to disconnect the thin black thermister wire at the back of the pack prior to pulling the tray out.  You will need an 11 1/2" high support capable of supporting 200+ pounds.

2. Disconnect all battery wiring from the batteries recording how they were connected.

3. Individually charge the batteries with an automotive style 12 volt charger, preferably one with a deep cycle setting.  Pay attention to the charge times as a failing battery can take longer to reach full charge.

4.  Load test each fully charged battery.  I took mine to a local battery shop for this.

5.  If all test good, go on to other test procedures.  If one or more test bad, call Ryobi for assistance in sourcing replacements.  Don't forget to have all of the numbers on the label under the seat handy for reference to the support person.

 

[Breischaft]

On 6/23/2021 at 9:16 PM, Breischaft said:

Called and talked to them.  Of course, mower not doing this at time, but knowledgeable service.  

 

Told me immediately that 12 meant bad connection to main drive and that’s where I should look.  If it continues and the wires are secure, they can send another drive for me to swap.  

 

I asked and he said he could send me the troubleshooting guide, which I got.  PM me if you’d like.  Agree with your comment: 12 beeps not on the list.  

 

Again super thanks to you, Jim.  I’d have never even counted the beeps before you asking about it. 

Will update here as things progress. 

 

Update: 

have cut twice now with no issue.

So the cause seems to have been loose connection on the main drive.  After getting this thought from ryobi tech help, I opened the panel in front of/below the seat and checked the connectors.  I did not see nor feel any that were loose.  But since the problem has not reappeared, I assume that by checking I secured a connector better than it had been.  

 

Again have to thank Jim on the counting of the beeps as this shortened a lot of troubleshooting.  

 

Hope to not come back to this, but will update again if there’s any more to this story.  

 

I do really like this mower.

 

thanks all

 

[jamis]

Great news Kurt.  Hopefully it's fixed and you have good performanc with it for a long time.  Today, I ran my RM480e longer than I ever have in the 35 months I've owned it.  I mowed for 1.5 hours non-stop, used 4.7 volts of the pack and the meter showed 42% of the charge used.  Not bad for a mower that's almost 3 years old and supposed to run for 2 hours.

[Moe1]

On 6/7/2020 at 9:37 AM, PaulNY said:

Hello, 

 

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. 

 

On 6/7/2020 at 9:37 AM, PaulNY said:

Hello, 

 

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. 

 

[Moe1]

On 6/7/2020 at 9:37 AM, PaulNY said:

Hello, 

 

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. 

 

[jamis]

This 100%/70% display is a common issue with the Ryobi ZTs.  Contact Ryobi at the number on the label under the seat.  Also have the model number, manufacturer number, and the serial number from the label handy when you finally get through to a support person.  Some users have had their meters replaced under warranty, with mixed results.  The Ryobi instrumentation on their mowers has been sketchy since they came out.  Better instrumentation would have driven the cost up, so we live with it.  I have been measuring the pack voltage at the beginning and end of each usage ever since I discovered the weakness in the meter.  The bottom two contacts in the charging port are positive and negative.  I started using a digital volt meter, and switched to an onboard volt meter plugged into the charging port, and just modified the meter on my RM480e to display volts, percentage remaining, and hours.  The beginning voltage should be above 52 volts at the end of the charging cycle, but the batteries will self discharge a bit just sitting.  After nearly three years, my batteries will be around 51 volts a week after a full charge cycle.

[Moe1]

15 minutes ago, Moe1 said:

 

I purchased my ZT480e (42”) May 2019. No problem with it that season. I’ve flown R/C electric planes for 30 years, With Nickel Cadium, Nickle Metal Hydrate, and Poly Lithium batteries (first with brushed motors, then brushless), so the first thing I did after buying my ZT480 was scour the web sites for best methods of charging these DeepCycle SLA (sealed lead acid) batteries and found only running them down 50% doubled their life expectancy so that’s what I’ve been doing from the first time I mowed! I’d get about an hour of mowing time on 50% (which mowed my 7/8 acre yard with about twenty trees). I also followed Ryobi’s suggestion to keep it plugged in when not mowing!

     In April last year (2020) it died after pulling it out of my garage and shutting it off for a couple minutes! I spent the entire day attempting to find a “Ryobi Authorized Service Center ( none of the nine Service Centers given to me by Ryobi would work on mowers!) Finally found a small mower repair shop that not only was “authorized” but had fixed three other ZT480e’s ( all three had battery issues). Mine however showed 52 volts on my multimeter and when they Stress Tested the batteries individually, ..  all was good! Turned out both of the motor controllers were bad. Ryobi charged him $150 each (and he was reimbursed after sending the defective controllers back for confirmation they were defective. I paid nothing!

He had my mower for SIX WEEKS however. When I picked it back up, ( supposedly repaired), my mowing time had been cut in half! only 25 minutes at 50% remaining! Not a Happy Camper! He said to callRyobi!

   I emailed them. Nothing! I emailed them again! nothing! Then I received an email from Ashlyn Hogg (Associate Product Manager,Outdoor Products Division). It was more of a questionnaire asking me how I liked it, and any feed back I could give them would be helpful! I gave them plenty! Including the battery meter only reading 70% if not used within 5 to 7 days, my meter dropping to 70% after 10 minutes of mowing but then running another 40 minutes before dropping to50% remaining! I received nothing back from anyone!

     This year (April 2021), with my batteries only being two years old, my mow time is about 15 minutes! My multi-meter still shows 52 volts (after spending the night on the charger) so I decided to buy a battery tester which tests the “Remaining Life Expectancy” of the batteries ( you have to disconnect all the plugs, pull the natter tray out,and test them individually).

   Here are my results: Battery #1… 1%…”REPLACE!”   #2…. 26%…REPLACE   #3…56%…GOOD    #4…57%…GOOD

   So much for only running them down 50%! TWO YEARS (instead of 

SEVEN to EIGHT!)

     I’m now asking Ryobi for an Authorized REPAIR CENTER (within 100 miles instead of the 35 trip I had last year for service because he had no electrical experience! Only worked on gas mowers till then. Had to order the technician’s manual from Ryobi. Had to make several callls to Ryobi and have them “walk him through the procedures. (They made him do the stress test on each battery and I can’t say with any proof but I believe the Stress Test ruined my batteries(or at least drained half their Life Expectancy! Come on! One year old batteries shouldn’t mow for only 25 minutes on 50% remaining!

 I’ve emailed Ryobi and requested they look at my mower and either make it right or give me a new one! I seriously doubt I’ll ever hear from them!

 

[jamis]

Remember that the system will not let the Depth Of Discharge (DOD) exceed about 30% (down to 36 volts) before it shuts the mower down.  So if you run the charge down to 50% on the meter, the real DOD is about 15%.  

Edited July 5, 2021 by jamis
text clarification

[Mowerguy1234]

Hi there!  I have the RM480e.  I noticed that the battery indicator shows volts, percentage, and hours remaining.  How do you switch between them to see the other two readings?

[jamis]

Ryobi has the BLM set up to show only the hours run.  There are at least three different versions of the meter on the RM480s.  One version has a mode button on the back of the meter that switches between the three modes.  Another version has no button, but has an unused lug on the back of the meter that can be shorted to the ground lug to switch modes.  A third version does not have the three mode lights on the face of the meter and I'm not sure if it can be modified to switch modes.  There is a YouTube video that shows how to modify the meter with the three mode lights so you can use a NO momentary switch button to cycle through the modes.  

https://www.youtube.com/watch?v=ny5R9DvjkCk

 

[jamis]

Here's a picture of my modified BLM meter.  The console on my mower was held down with seven screws and I figured the one between the key switch and meter was not really needed as newer mowers don't have that screw.  The screw hole was exactly the right size for the miniature push button switch I used per the video.  I've only used it for three mows so far, but it works really well.  The meter defaults to hours every time you switch the key on though.  

[Mowerguy1234]

43 minutes ago, jamis said:

Here's a picture of my modified BLM meter.  The console on my mower was held down with seven screws and I figured the one between the key switch and meter was not really needed as newer mowers don't have that screw.  The screw hole was exactly the right size for the miniature push button switch I used per the video.  I've only used it for three mows so far, but it works really well.  The meter defaults to hours every time you switch the key on though.  

 

this is awesome!  Can you tell me where you got the actual switch that fits in the screw hole?

[jamis]

2 hours ago, Mowerguy1234 said:

 

this is awesome!  Can you tell me where you got the actual switch that fits in the screw hole?

The switch is a Normally Open, miniature push button switch.  I got mine from my neighbor who is an electronics maven, who bought them off of the internet.  He is my neighborhood Radio Shack, which is where I would have gone if we had any of those stores left around here.  The electrical values are of little importance as there is no measurable current between the ground lug and the one used for cycling the meter.  I measured things with a digital VOM before I attempted the project.  Literally, any miniature switch you can find that fits in a 1/4" hole will be sufficient. 

[jamis]

For nearly three years, I've been trying to figure out how the Battery Level Meter works with no help from Ryobi and I hope this meter mod will provide the additional data to accomplish that.  I've been recording volts used, time mowed, bars out, recharge watts, and turf conditions plugged into a spreadsheet to reverse engineer how the meter decides when to turn a bar LED off.  So far, I can link nothing, or see a pattern to things.  

[Cultus]

Hi Guys.  Does anyone know if these batteries can be crossed with a better brand like Trojan or are they proprietary?

 

I'd be inclined to swap the lead acids out for AGM (gel) batteries after a couple years.

 

Any idea of what the Trojan model would be?

[jamis]

The last time I looked, the Trojan lithium batteries that would fit were out of stock and incredibly expensive compared to the SLA/AGM batteries (like by a factor of four). The Leoch LPC12 batteries are NOT proprietary as they are used in wind farms, solar arrays, golf carts, UPS installations, and mobility devices.  The batteries supplied in these mowers are SLA/AGM industrial grade batteries.  In addition, the electronics in these mowers will NOT work with lithium technology.  It's been stated so by Ryobi and someone who tried it.  You would have to change all of the controllers/processors in the mower and get a new charger.  The supplied batteries in these mowers are rated to do 1,500 - 1,700 charge cycles.  By comparison, the lithium batteries in the new Ego 42" zero turn rider are rated by Ego for 1,000 charges.  Tesla stated back in March that the current batteries in their cars are rated for about 1,600 charge cycles.  HD is now selling Mightymax SLA/AGM batteries in group 24 and 31 case sizes which will fit in these mowers.  I'm trying to get Mightymax to state the charge cycle counts for these batteries.  Leoch has a new model (LDC12) of SLA/AGM batteries out that are rated for 1,700 - 2,000 charge cycles.

Edited July 6, 2021 by jamis
added text

[jamis]

For those out there that are modifying the BLM to display volts, %, and hours run; be prepared to be confused unless you are an electrical engineer.  After four mows with the mod., I still can't equate usage to how much battery charge is used with each use.  However, I mowed today for 1.6 hours, used 2.8 volts of the available charge, and the BLM showed 78% left with 3 bars out.  Last week, I mowed the same 26,000 sq.ft. of lawn for 1.4 hours, used 4.7 volts of the available charge, and the BLM showed 58% left with 5 bars out.

 

Confusing, but given the mower is 35 months old with 137 mows, 97 hours of use, and 193 charge cycles, it still mows as well as it did new.  The RM480e is supposed to be good for two hours of run time and mine just did 1.6 hours with waaaay more than half of the available charge left.  

Edited July 6, 2021 by jamis
added blather

[jamis]

So far, the BLM mod has shown me that the bars out is directly related to the percentage left.  0 - 9% = 0 bars out, 10 - 19% = 1 bar out, and so on.  I still can't figure out how the meter calculates the percentage remaining.  I can't correlate time, voltage, temperature, recharge watts, ground speed, or mowing conditions to percentage.  What I can determine is that charge usage is highly variable based on several factors, so I can mow the same sq.ft. and get different readouts on the BLM.

[jamis]

Gotta brag.  We have been inundated with rain for the last couple of weeks and mowing has become a task to get done between storms.  I recently mowed  two 10,000 sq.ft. lawns and the 16,000 sq.ft. lot next door on a single charge.  Total run time was 2.3 hours and I mowed until the deck motors shutdown.  When I got back to the charger, the BLM was at one red bar, 9% available, and 42.2 volts.  Beginning voltage was 51.5 volts.  Also, since the hour meter has been 7% understated, the actual run time was 2.5 hours.  Not bad for a 35 month old mower with 97 hours of run time and 195 charge cycles that is supposed to run for up to 2 hours.  The recharge consumed 4,050 watts, which cost me $0.53 in electricity and took 9 hours to complete.

Edited July 16, 2021 by jamis
added blather