From what I've read, the Ryobi 18v also do not balance, only cell-level monitoring. Just like DeWalt, etc. I'm not sure about the 40V.
They just appear to count on the fact that they use high-quality well matched cells. But I can tell you from experience with DeWalt packs, once they get about 5 years old, they are markedly unbalanced and that causes a lot of lost capacity. On Sat, Oct 11, 2025 at 7:51 PM Bill Dube via EV <[email protected]> wrote: > I am very happy with Ryobi batteries and tools, so that is what I > adapted to my eBike. The Ryobi batteries seem to last quite some time. I > have perhaps 40 tools and perhaps 15 batteries, and I can only recall > perhaps two or three battery failures over the 15? years I have used > them. (The NiMH packs that were in use ~20 years ago would indeed wear > out and die after a couple of years, but the lithium packs seem to work > nearly forever.) Zero tool failures, but I am probably easy on power tools. > Thus, I strongly suspect that the internal BMS does some cell > balancing. The packs wouldn't last very long if they did not do any > balancing. Not terribly expensive to implement compared to the big > transistors required for the over-current/under-voltage disconnect. > I used the ~40 volt lawn mower battery without modification. We > pressure-washed it off when it was covered with salt-flat salt and that > ruined the battery as it filled with saturated salt water. 😳 The 40 > volt batteries can are designed to put out far more than the 18 volt > batteries. Thus, the internal disconnect for over-current, over-temp, > and low voltage wasn't touched. The eBike loved the 40 volt Ryobi as it > arrived out of the box without alterations. > > Bill D. > > On 10/8/2025 2:46 AM, Peri Hartman via EV wrote: > > That's a great idea ! It seems it would hold true for all the portable > > tools, milwaukee, makita, dewalt, ... Or, is the form factor of the > > ryobi lawnmower better for an e-bike ? > > Peri > > > > << Annoyed by leaf blowers ? https://quietcleanseattle.org/ >> > > > > > > ------ Original Message ------ > > From: "Bill Dube via EV" <[email protected]> > > To: [email protected] > > Cc: "Bill Dube" <[email protected]> > > Sent: 06-Oct-25 22:51:26 > > Subject: [EVDL] Ryobi-powered eBike (was: Batteries for eBike) > > > >> Awhile back I adapted a ~40 volt Ryobi lawnmower battery to fit my > >> eBike. Seems to work perfectly. > >> > >> I bought a "dead" Ryobi grass trimmer on eBay for about $20 that used > >> the large Ryobi battery. I dissected the trimmer and extracted the > >> "shoe" connector for the battery. Attached it to my eBike. > >> > >> The Ryobi ~40 volt battery comes in several Amp-hour sizes, so you > >> can chose the size that suits your needs (and your budget.) > >> > >> The Ryobi has a built-in BMS and you can (you _should_) use the stock > >> Ryobi charger. Ryobi has a sterling reputation and thus a bulletproof > >> BMS. The battery has under-voltage, over-voltage, over-temperature, > >> and short circuit protection. What more could you ask? > >> > >> Bill D. > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20251012/0b499e59/attachment.htm> _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
