Ryobi RM480e not operational after winter storage.

[Fourdoor]

Is your mower fixed yet? I am having almost the exact same problem now. I did not plug in the power core during the entire winter. I had it fully charged before my first test use, the mower however did not move much, I somehow got it started by turning on the blade. Then I put it back to the shed. Now it would not start at all, just like what you have described. The batteries are showing 50V.
I also did what other people suggested, try to turn on, and observed the voltage went down to 16V immediately. The voltage went back to 50v slower after I stopped the key turning.
I decided to charge the battery individually, and found 1 battery is full, and 3 other batteries are pretty empty. I think that explains why I got 16V, that’s probably 12V + very low amount from other 3 together.

Well, I am charging 1 overnight, hope I can bring the batteries back.

I found my problem, either when I pulled the battery tray out, or slid it in after individually charging each cell I snagged one of the cables that goes above the battery pack and un-plugged it. After plugging that in the mower worked and mowed!!!

But it still had pathetic run time Less than half an acre of run time when mulching dry, not too tall grass, not enough to do my 2/3 acre lawn on one charge. I bought a "real" (non-harbor freight) battery tester and 1 cell had 297 CCA, one had 275 CCA, one had 240 CCA, and the last one had 237 CCA. Since I needed to replace at least two of the cells (and the third is "iffy") I decided to upgrade to 100 ah pack from the 75 ah pack I originally had.

With the new pack installed I was able to do my entire lawn and only used about 1/4 of the battery!

I purchased a desulfator/charger and will attempt to restore the old 75 ah cells to health... if they are revived I can make a home energy storage pack that will run a fridge and freezer though a power outage... or sell them on e-bay. If they don't revive, I will sell the old cells as scrap. I didn't learn about desulfators until after I had purchased my new 100 ah battery cells... my recommendation to you would be after charging each cell full, to purchase a good battery tester OR take the cells to one of the chain parts stores that offers free battery testing. If one or more of the cells are bad I recommend trying restore those cells with a battery desulfator before spending the money on new cells.

Good luck,

Keith

 

[Tony120]

Same problem here, only worse: smoking.

Last year, we had a problem with the mower not being able to cut our whole half-acre lawn. After a trip to the local service center, they replaced one battery and that seemed to do the trick.

However, this spring, the mower was dead, completely, no lights, nothing. And it wouldn't charge using the port. I pulled the battery pack and disconnected all the batteries from each other. (I took photos first so that I could put it back together right.) I charged each to full and then let them sit overnight. The three old ones all dropped to 10v or lower overnight.

So, I ordered three new batteries and installed them. I tested the battery pack and it was putting out 50v. I connected everything and took a test run. The mower was running great for about three minutes and then it went completely dead. I looked at the wiring diagram and found the 125A fuse location. It was blown. I ordered a new fuse from Ryobi which just arrived. I installed the new fuse and turned the mower on. It looked OK for a minute and then I noticed smoke (electrical from the smell) coming from the left rear hear the height adjustment lever. I quickly shut it off and disconnected the battery pack.

I know this is going to be a trip to the service center and probably $$$. Does anyone have any ideas what might be wrong?

 

[sgkent]

EX batteries, chewed and chaffed wires eh? someday they will figure how to make them last.