jamis Posted May 27, 2022 Report Share Posted May 27, 2022 Just some thoughts on the instrumentation of these mowers. After 45 months, 342 charges, 124 hours of use, I have come to the conclusion that the number of variances in mowing and the discharge characteristics of the batteries makes the meters pretty much inconsistent. Using my spreadsheet data, I grouped all of the runs that used 7 to 9 bars on the BLM. One 8 bar mow of 1.4 hrs required 3,610 watts to recharge. A year later an 8 bar mow of 1.3 hrs. required 3,270 watts. This was the same sq.ft., just 6 min. difference in time. This week a 9 bar mow of 1.6 hrs required 3,330 watts. Last year a 9 bar mow of 1.7 hrs. required 4,050 watts. Again, the same sq.ft. The voltage drop of these runs ranged from 3.6 volts to 8.3 volts. the only thing I have been able to determine from the data is that the average cost per use has been increasing by about $0.02 each year, and the cost per hour has been increasing about $0.03 per hour each year. Overall cost per hour for the 45 months is $0.256 per hour. I have been paying $0.13 per KWH for electricity. I have spent a total of $31.86 for electricity for runs over the 45 months. Add in winter storage costs and the total cost of electricity is $37.03 This tells me that my batteries are aging slowly, but still have plenty of life left. Quote Link to comment Share on other sites More sharing options...
sailracer Posted May 27, 2022 Report Share Posted May 27, 2022 I put in the new MightyMax 75Ah battery to replace my original battery that I concluded was bad and it seems to be working perfectly. So far I don't see any evidence of a problem mixing Leoch and MightyMax. The terminal positions are slightly different on the MightyMax but the battery jumpers still reach them easily, and it has a fabric lifting strap instead of plastic handles. I mowed last night and finished with 35% battery remaining instead of either flashing 5% or blades shutting off before I was done, so it looks like it was another premature Leoch battery failure and replacing it resolved the problem. Here's a picture. I discovered this morning I forgot to put the plastic battery covers back on. Is it worth taking everything apart again to put them back on or should I just run without them until the next time I need to service a battery? Quote Link to comment Share on other sites More sharing options...
jamis Posted May 27, 2022 Report Share Posted May 27, 2022 The battery covers are for dust protection, so it's your choice. If it were mine, I'd put them on. Glad to hear the new battery works. Quote Link to comment Share on other sites More sharing options...
sailracer Posted May 27, 2022 Report Share Posted May 27, 2022 On 5/25/2022 at 10:15 PM, jamis said: As to the CCA question, I can only say that Ryobi's troubleshooting process is to run a load test on the batteries to see what the condition is. The $40 load tester my neighbor bought, and the commercial load tester the local battery shop used, both measured voltage drop under load vs time to determine the health of the batteries. I'm no expert, but if that's what the manufacturer says is to be done, that's what I'll do. I also find it interesting that both Leoch and MM deep discharge style batteries don't list the CCA of these batteries. I do know the Leoch batteries are used in wind farms, solar arrays, UPS installations, and mobility devices where CCAs are not important. I'll add my conclusions after experimenting with my batteries and tester. For a typical car battery for starting an engine, CCA is important. The batteries are designed for supplying large amps over a short period of time. They are also not meant to be deep discharged and need to be fully charged to operate effectively, so car starting batteries are tested at full charge. Deep cycle batteries aren't designed for outputting large amounts of current over a short time but instead are designed to output a working current for a long period of time and be able to sustain that current as the battery discharges. Deep cycle batteries can still generate a large current in short time, but the amount of that current is dependent on the state of charge and may not be a good indicator of battery health, so any tester that only tests for a short period of time may not be able to detect a problem with a deep cycle battery, particularly if it is a problem that requires heat build up in a battery to show up. The small, consumer load testers like the one I tried, are designed for measuring that peak current over a very short period of time and the tester determines health by comparing that current to the rated CCA of the battery. The much bigger commercial load testers are likely using a test method with better heat dissipation so they can test for a longer period of time and can observe voltage drop over that time period. They can safely apply a load for many seconds to see if the battery charge can hold up over that longer period of time. That seems more likely to find a problem with a deep cycle battery, but still may not be sufficient. If the load current is high, it isn't testing the deep cycle battery the way it was intended to be used. If the load current is lower, it may take a long time to determine its state of health. Looking at the battery discharge graph I posted earlier, using highest current discharge they show (depletes the battery in 30 minutes, which extrapolating from tables in the datasheet suggests the current is around 85A) it takes 8 minutes of load at 85A for the voltage to drop from 11.9V to 11.6V. To test that, the load tester would have to dissipate >1000W for 8 minutes. That's a big toaster worth of heat! The measured CCA with my small meter showed approximately 40A of difference between the 4 batteries in my mower when fully charged. The battery that ended up being bad was actually one of the ones with a high CCA measured by the charger. With the blades running (drawing an approximately constant load I estimate to be around 30A) all of the batteries had a very similar measured voltage when all were fully charged. Even the bad battery was able to output the required current without showing an abnormal voltage drop when fully charged. Depending on how much current a battery load tester draws and for how long, it may not detect a problem with this battery when fully charged. Once the deep cycle batteries had been discharged more, things started to change. The consumer battery tester showed the CCA of all 4 batteries dropped. The bad battery dropped more than the others, but was still putting out 360 CCA when mostly discharged. The others were at 400 to 430. That alone can't diagnose the problem, but now the voltage on the bad battery was reading only ~10.5V while under load whereas the good batteries were still at 12.3V. Another clue- the bad battery had a spot on the case that felt hot to the touch after discharging for an hour. I don't know that any load tester can run a battery long enough for it to heat up internally like that. Maybe there is some clue in the voltage/current before the battery heats up or at much higher currents maybe it shows up quickly. Maybe someday if I get around to it, I will take my bad battery to a shop for testing to see what they say. In terms of power, the bad battery is putting out a little bit less than the good batteries. Since they are wired in series, the current through them is the same, only the voltage differs, so the bad battery is putting out about 15% less power than the good ones based on the voltage difference. The Ryobi battery management seems to key off voltage for battery state of charge, however, and thinks that this much drop in voltage means the pack as a whole is more discharged than it actually is. The battery still seems to have the charge in it, but is not capable of outputting it at the current required which causes the voltage to drop. If the bad battery sits and cools down, the voltage comes back in line with the other batteries and the Ryobi gauge goes from reading 5% up to 40% and is happy again and the mower can run for longer. So, whatever is wrong with my battery internally, it seems marginal right now (but getting worse over time) and only shows itself when the battery has been running long enough to build up some heat internally. For those trying to determine if it is time to replace all of your batteries and want to diagnose it yourself, I would say do an extended load test to determine if there is one battery in particular causing your pack voltage to drop as the batteries discharge or if all of your batteries are dropping the same and have worn out evenly. 1 1 Quote Link to comment Share on other sites More sharing options...
glennfin Posted May 30, 2022 Report Share Posted May 30, 2022 (edited) That's great news about the MAX battery!,,,, I will be changing all the batteries and there will be considerable savings if I go with the MM's. Did you have any issues with charging? Also, did you pre -charge the MM before you installed it? I'm assuming you did.. Edited May 30, 2022 by glennfin Quote Link to comment Share on other sites More sharing options...
sailracer Posted June 1, 2022 Report Share Posted June 1, 2022 On 5/30/2022 at 10:27 AM, glennfin said: That's great news about the MAX battery!,,,, I will be changing all the batteries and there will be considerable savings if I go with the MM's. Did you have any issues with charging? Also, did you pre -charge the MM before you installed it? I'm assuming you did.. So far I haven't had any issue with charging. The mixed pack charged back to 100% (52.9V) overnight. I'll check later this week to see if it has the self discharge problem where it drops a volt and reports 70% when on the charger for a week or more. The MM battery ordered from Amazon came mostly charged I think. It read 13V when it arrived. I put it on a trickle charger for 24 hours before installing it in the mower with the other fully charged batteries. 1 Quote Link to comment Share on other sites More sharing options...
jamis Posted June 1, 2022 Report Share Posted June 1, 2022 FWIW, as the batteries in my RM480e age from use & charging, I'm documenting an increase in the cost per hour of use at $0.01 per hour each year. In other words, it now costs $0.04 per hour more to run my mower than it did the first year. Since everyone uses their mower differently and each use can have different factors, this is the one measurement that I think reflects how to measure the battery aging process. As of today, the cost per hour is at $0.258. By comparison, my neighbor's Toro V-Twin rider uses a gallon of gas per hour and the current price of 87E10 is $4.799/gal. Quote Link to comment Share on other sites More sharing options...
sailracer Posted June 3, 2022 Report Share Posted June 3, 2022 On 5/31/2022 at 8:07 PM, sailracer said: So far I haven't had any issue with charging. The mixed pack charged back to 100% (52.9V) overnight. I'll check later this week to see if it has the self discharge problem where it drops a volt and reports 70% when on the charger for a week or more. This week the mower was still at 100% after sitting for a week on the charger. While I wouldn't call this conclusive, it is a datapoint supporting the idea that the 70% reading problem could be related to a bad battery self-discharging faster than good batteries. I'll keep checking as the time between mowings increases later in the summer. Update- one week later and the 70% problem returned. I did notice that the finishing % when I was done with my lawn was the same as the week before when it started from 100%, so it seems like it must just be a voltage variance sensitivity reading when the batteries are fully charged and doesn't really reflect 30% less energy in the batteries. 1 Quote Link to comment Share on other sites More sharing options...
TotalRex Posted June 3, 2022 Report Share Posted June 3, 2022 HELP, Anyone know who has a replacement battery for the RM480e in stock? Home Depot's site says they do, but I ordered one two weeks ago and they keep emailing me that shipping is delayed. They do not have them in stock. I just need one right now. One of my batteries is dead according my tester while the are 3 are 'OK' Quote Link to comment Share on other sites More sharing options...
jamis Posted June 3, 2022 Report Share Posted June 3, 2022 (edited) Apparently, the Mighty Max SLA/AGM batteries sold by HD work in these mowers. My neighbor ordered one of the 100 ahr. Leoch batteries from HD three weeks ago and received it within days. It restored his mower's performance to like new. Edited June 4, 2022 by jamis added blather Quote Link to comment Share on other sites More sharing options...
TotalRex Posted June 11, 2022 Report Share Posted June 11, 2022 I replaced a bad battery with a new one, but I am getting the same results. The mower runs for few minutes then stops moving. If I lift off the pedal it moves again for a few feet than stops. Then the blades turn off. I can then drive it back to the garage but only slowly. If I push all the way down on the pedal it goes for a few feet then stops. WilI need to replace all the batteries? Or should I try one more? My tester says the other 3 batteries rate at ~380-400 CCA if that helps. The new battery says ~500. Quote Link to comment Share on other sites More sharing options...
TotalRex Posted June 11, 2022 Report Share Posted June 11, 2022 1 hour ago, TotalRex said: I replaced a bad battery with a new one, but I am getting the same results. The mower runs for few minutes then stops moving. If I lift off the pedal it moves again for a few feet than stops. Then the blades turn off. I can then drive it back to the garage but only slowly. If I push all the way down on the pedal it goes for a few feet then stops. WilI need to replace all the batteries? Or should I try one more? My tester says the other 3 batteries rate at ~380-400 CCA if that helps. The new battery says ~500. An update. I had a 2nd new battery and so I replaced a 2nd old one (long story HD sent me an order I cancelled). I guess that raised the total power to be enough to run the mower. I was able to mow the front lawn without it stopping this time. I am going to fully charge it again and try my back yard which is a little over 1/3rd of an acre. Question, I read to wait until batteries cool down before recharging. Is that true? Quote Link to comment Share on other sites More sharing options...
Cerberus Posted June 11, 2022 Report Share Posted June 11, 2022 So where can you get the batteries tested to see if they are failing? I tried my local Batteries Plus and they said they don't test SLA batteries. Should I be looking at lawn/garden or automotive places? Quote Link to comment Share on other sites More sharing options...
jamis Posted June 12, 2022 Report Share Posted June 12, 2022 TotalRex: the charging system has a thermistor connected to the batteries to prevent overheating during the charging cycle. It's that little black wire and white connector at the rear of the battery pack. It is wired into the safety and control logic circuits in the back of the charging receptical. Testing a SLA/AGM deep discharge battery with a CCA tester is not the correct method. It won't give you the correct results for this application. They need to be tested with a proper load tester for the deep discharge use. Cereberus: My local battery shop (Battery Wholesale) had no issues testing my SLA/AGM batteries for free even. Some new cars have SLA starter batteries, so maybe the auto parts shops can test them. Have any Interstate Battery stores around? How about trying a golf course cart shop to see if they can offer suggestions? Suggest Batteries Plus isn't very PLUS. Is there no other battery shop in the area? My neighbor bought a 100 amp battery load tester from Amazon for less than $40 to test his. Quote Link to comment Share on other sites More sharing options...
jamis Posted June 12, 2022 Report Share Posted June 12, 2022 (edited) I discovered an interesting fact about the batteries in my RM480e. My mower is in its fifth mowing season and my recorded data shows that as the batteries age, the cost per hour of operation is increasing. The cost per hour has gone up 1.3 cents per hour per year. So now the cost per hour to mow is at 25.8 cents per hour. I don't see any run time reduction, just a bit more charging watts. To put that into perspective, my neighbor's 42" Toro Timecutter V-Twin burns a gallon of 87E10 per hour. When I bought my mower, gas was $2.50 a gallon, it's now $5.10 a gallon. That makes my electric mower 19.76 times less expensive to use. I have spent a total of $32.78 for electricity to mow lawns for over 46 months. Including winter storage, the total electricity cost has been $37.94, or 82 cents per month of ownership. Edited June 12, 2022 by jamis added blather Quote Link to comment Share on other sites More sharing options...
JeremyA Posted June 15, 2022 Report Share Posted June 15, 2022 Jamis - what load tester did your neighbor buy? Quote Link to comment Share on other sites More sharing options...
jamis Posted June 16, 2022 Report Share Posted June 16, 2022 12 hours ago, JeremyA said: Jamis - what load tester did your neighbor buy? Not sure. It was less than $40 and he got it off of Amazon. I think it is this one, because it has the switch at the bottom for starting/stopping the test without messing with the leads. https://www.amazon.com/OEMTOOLS-24338-100A-Battery-Tester/dp/B07FQ1G327/ref=sr_1_8?gclid=Cj0KCQjwhqaVBhCxARIsAHK1tiN3qLLzu-Q-aGD4vR5O16SRyYdCN6yc2GAORc2jd1v3WfKm92KFzGcaAlsCEALw_wcB&hvadid=580743546407&hvdev=c&hvlocphy=9015090&hvnetw=g&hvqmt=e&hvrand=14902647177619769028&hvtargid=kwd-398861394456&hydadcr=7501_13212144&keywords=battery+load+tester+100+amp&qid=1655341525&sr=8-8 Quote Link to comment Share on other sites More sharing options...
CRP Posted June 19, 2022 Report Share Posted June 19, 2022 On 6/24/2021 at 9:22 AM, Breischaft said: my lack of attention to detail: only beeps when left lever pushed or pulled, leading to the main drive not the slave. Ok, so I am new to this… unpacked it and assembled it per instructions. The moment I went to drive it off the metal crate, this happened to me. Left lever makes it beep and there is no forward or backwards movement. Blades engage so it’s not the switch under the seat. Anyone have any ideas to what this might be? I mean, I know it’s frustrating as F%*k but that’s about all I can gather at this point!! Any help? Quote Link to comment Share on other sites More sharing options...
Cerberus Posted June 19, 2022 Report Share Posted June 19, 2022 On 6/11/2022 at 7:01 PM, jamis said: Cereberus: My local battery shop (Battery Wholesale) had no issues testing my SLA/AGM batteries for free even. Some new cars have SLA starter batteries, so maybe the auto parts shops can test them. Have any Interstate Battery stores around? How about trying a golf course cart shop to see if they can offer suggestions? Suggest Batteries Plus isn't very PLUS. Is there no other battery shop in the area? My neighbor bought a 100 amp battery load tester from Amazon for less than $40 to test his. Thanks for the tips! Interstate in the area tested them - only charged me $5 and probably only because I asked how much. All four batteries tested bad and Ryobi is sending me a completely new set. From what I saw, the mower was mfg in 2019 and I bought last year. I'm guessing the time in storage probably trashed the batteries. BTW - the only reason I got to this point was reading this thread. So much good info here. Most appreciated. Quote Link to comment Share on other sites More sharing options...
CRP Posted June 19, 2022 Report Share Posted June 19, 2022 16 minutes ago, CRP said: Ok, so I am new to this… unpacked it and assembled it per instructions. The moment I went to drive it off the metal crate, this happened to me. Left lever makes it beep and there is no forward or backwards movement. Blades engage so it’s not the switch under the seat. Anyone have any ideas to what this might be? I mean, I know it’s frustrating as F%*k but that’s about all I can gather at this point!! Any help? 17 minutes ago, CRP said: Ok, so I am new to this… unpacked it and assembled it per instructions. The moment I went to drive it off the metal crate, this happened to me. Left lever makes it beep and there is no forward or backwards movement. Blades engage so it’s not the switch under the seat. Anyone have any ideas to what this might be? I mean, I know it’s frustrating as F%*k but that’s about all I can gather at this point!! Any help? Btw, after reading the thread I went out and counted, I have 11 beeps, not 12. This is infuriating! Quote Link to comment Share on other sites More sharing options...
jamis Posted June 20, 2022 Report Share Posted June 20, 2022 (edited) CRP: Since your mower is brand new, you really need to contact Ryobi for assistance. Use all of the information from the label under the seat when you call them. I'm not that familiar with the ZT4480s so contacting Ryobi is the best I can offer at this point. Since none of the supplied manuals discuss the number of beeps, Ryobi definitely needs to be contacted. Just remembered I have the troubleshooting guide for the ZT480 mowers and upon checking, there is no stated beep count for any issues. Still the best thing to do is to contact Ryobi with a warranty issue. Also find out where the nearest Ryobi Authorized Outdoor Service Center is. Be aware that the one nearest me (1.5 mi.) is horribly backlogged with repairs as they also do John Deere, Honda, Stihl, and Toro stuff. HD has a 90 day return policy also. Here's what the troubelshooting manual states for the mower not moving: If the mower will not drive a. Make sure the seat switch is functional and activated. b. Test the angular transducers. Replace if necessary. c. Test the neutral switches. Replace if necessary. d. Test the brake switch. Replace if necessary. e. If the mower still will not drive, test the Drive Motor controllers. Replace if necessary. f. Test the drive motors and Hall sensors, replace as necessary Edited June 20, 2022 by jamis added blather Quote Link to comment Share on other sites More sharing options...
jamis Posted June 20, 2022 Report Share Posted June 20, 2022 Cerberus: Leoch states the LPC12 batteries can sit for up to six months without a maintenance charge if stored in the proper conditions. And they and Ryobi stated they should be maintained at least every month once used in the mower. Probably why Ryobi is replacing them all. When they replaced my one failed battery under warranty, It was overnighted via UPS. Quote Link to comment Share on other sites More sharing options...
Cerberus Posted June 21, 2022 Report Share Posted June 21, 2022 On 6/20/2022 at 11:30 AM, jamis said: Cerberus: Leoch states the LPC12 batteries can sit for up to six months without a maintenance charge if stored in the proper conditions. And they and Ryobi stated they should be maintained at least every month once used in the mower. Probably why Ryobi is replacing them all. When they replaced my one failed battery under warranty, It was overnighted via UPS. Yeah, with the weight of all four it's coming common carrier. Good news is I'm getting good at taking the batteries in and out so it won't take me long to swap them 😉 BTW - I think there was mention of a service manual for the RY48ZTR75 at one point. Is that available anywhere? My searches have come up dry... Quote Link to comment Share on other sites More sharing options...
jamis Posted June 21, 2022 Report Share Posted June 21, 2022 The ZT480 Troubleshooting manual. I don't have the repair sheet showing parts and p/ns. zt480 1741877491_RYOBIZTRMOWERREPAIR4-18-2019.pdf 1 Quote Link to comment Share on other sites More sharing options...
jamis Posted June 24, 2022 Report Share Posted June 24, 2022 The RM480 Troubleshooting manual. rm480 1203847705_RYOBIRIDINGMOWERREPAIR9-4-201838inch.pdf 1 Quote Link to comment Share on other sites More sharing options...
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