I'm looking to convert my 20" McLane self-propelled reel mower to electric using a 60V brushless DC motor. I want to use three of my Milwaukee M18 12Ah Forge batteries, which together provide around 54V. However, I'm a bit worried about the health of the batteries and their built-in battery management system (BMS). Would running those batteries in series pose a risk? Is there a way to ensure they're protected? Do these batteries already come with BMS? I'm aware that I could simply buy a dedicated 60V battery, but I'd prefer to utilize my existing Milwaukee batteries. I'm still learning about electronics, so I'm sorry if this sounds silly. Thanks for any help!
2 Answers
I get your dilemma! There's definitely a risk of damaging your batteries if you just connect them. They might have some intrinsic BMS, but putting them in series like this isn't recommended without proper interface electronics to keep everything balanced and safe. It's cool that you want to use what you already have, but for peace of mind and battery longevity, you might want to consider an alternative system.
Just diving in and wiring those three batteries in series isn't a good idea. Milwaukee's M18 tools have specific circuitry, and it looks like those batteries need unique electronics to work safely together. If you really want to use them, you'll need to isolate each battery and consider a voltage converter to get you to 60V, but be warned—this could get pricey. Honestly, if it were me, I'd opt for a 60V battery setup instead. It'd be cheaper and easier to manage, plus you can add balancing features to keep everything running smooth.