It works!!!! Just got done with the first cut. Had 58% battery left after 1.25 acres! No bogging down or anything. I can do burnouts in my drive too! The weight of this rig is about the same as just one of my 4 SLA batteries. So pumped. Here are build pictures along with descriptions. It's...
I seriously cannot believe the interwebs sometimes. I started this thread with a question that I assumed was extremely niche but got valuable feedback. After which, I saw multiple people do similar builds (and some a lot better!) for the mower that I didn't think anybody else even had. Crazy...
Hi. I'm new to the forum. I have a 48V Ryobi Zero Turn that runs off of (4) 100AH AGM batteries. It's been about three years and now I can't get through a full cut. I would like to upgrade to LiFePo4 batteries. I'm thinking of using these ones...
@Nandologist I'm not sure where prices are right now but building it yourself shouldn't be twice the amount of money. I ended up spending $1100 vs. $800 for AGM. And I shouldn't need to ever worry about changing batteries again. I would get the use out of your existing batteries but if you...
I just completed this exact build. It was fun. Here ya go. https://diysolarforum.com/threads/ryobi-zero-turn-mower-sla-to-lifepo4-conversion-updated-build-complete-with-pics.22922/post-349628
Oh it's got a user manual! A very detailed 80 page one (https://github.com/FurTrader/OverkillSolarBMS/raw/master/Overkill_Solar_BMS_Instruction_Manual.pdf)!
Yeah, I think I'm just going to lower the full charge voltage and likely get new charger. The Overkill Solar BMS shouldn't need whatever...
Great news rio! Good luck with everything I've got some updates too.
1.) I dialed down the voltage to 56V using variable resistor VR2. Worked perfect and no more overvoltage! This should allow the cells to better balance while plugged in too. The charger now shuts off at 56V, cells top...
Thanks for everyone's help on this! I ended up getting in on a group buy discount with Michael and went with Ganfeng 100AH cells and an Overkill 48V 100A BMS. I'm currently searching for an ABS flight case that I might be able to use to house everything. Excited to get everything!
OK. I just did a mow with my meter. It seems that with a good charge, I average around 50A draw. There doesn't seem to be any peak at startup. However, when voltage drops I peak at around 100A for a second or two. This is with a near dead battery going up a steep and mowing though. So, it...
Cool, it's gone pretty smoothly and honestly when all is said and done, it isn't going to end up being much more than replacing SLA. I was able to do the conversion for just barely over $1000. New SLA's would have cost me $700. That's a no-brainer as far as I'm concerned. Glad I did it thus far.
I'm not sure on that one. I might. The BMS has hot/cold disconnect so it probably won't hurt. But I'd probably lower the full charge voltage on the BMS to like 50-60% if I did that which is recommended for long term storage from what I've read. I might just leave it disconnected and...
Thanks guys. Regarding mowing the grass in the winter. Ha! ...uh, no. I store the mower in the shed which is unheated. I live in Ohio and winter season runs 4-5 months. I didn't want to leave it unplugged and sitting the entire time so I just planned to automate a disconnect on freezing...
No, that wasn't me. That's pretty funny though. I'm still waiting on the cells unfortunately. I ended up going with an overkill solar 16S 100A BMS. It will be plenty. It's 100A continuous and peaks much higher than that for up to 30s. I have the BMS and a Pelican case that I'm using to...
One other question I have... Since I don't need anywhere near the capacity. Do you think I should change the max charge to something less than 100% to maximize battery life? I know this is the case with my car which uses Lithium Ion. Is LiFePo4 similar with max charge and longevity?
Got my gauge installed and fixed my cell last night! Gotta say those Heli-Coil things are AWESOME! Work great. Also got a smaller torque wrench that I could use for future so I don't do it again! Grinding out that hole for the gauge absolutely sucked by the way. I used my Ryobi zip tool with a...
Looks good! I haven't had any problem with the Overkill 100A BMS. The mower rarely peaks to 100A. I think the max I hit according to the BMS was 91A during my mow in a dew filled yard and many hills. The charger works fine but I do need to dial it down. For the GFCI trip, I definitely just...
I like how yours takes up less space but you might want to consider building an enclosure like this. I just reused the foam that came with the cells. I also put a layer on top before I screw the cover on it.
Here's how I handled the charger.
OK. So, you guys have helped me to convert my Ryobi Zero Turn 48V SLA/AGM mower into a LiFePo4 mower (still waiting on parts). I'd like to dabble into solar now. Here is the challenge.
I want to power my shed which will in-turn charge the mower. My current draw is currently just a couple...
Nice picture. Yep. That's exactly it. But 280ah! Damn... I'd be able to cut the whole neighborhood with that. That would seem to be expensive no? Any suggestions/links on a low cost 100ah+ cell and a a good housing that I can strap these together in?
Yes, it's allowed up to 48V by the manufacturer. I won't be bogging down if I have full voltage. That couple second 100A draw was when I was reading 40-44V. I'm expecting these batteries to average around 50A and peak at around 80A worst case. There really is no point in going past 100AH...
Hmm.. I just realized that the BMS software says Alert Cell Undervoltage Protection. I think this is a hardware cutoff. Reading through the BMS manual I might be able to lower the undervoltage release temporarily to "unlock" it which should then allow my charger to work as well. Maybe???
Also, regarding zero turn electric mowers... This wasn't available when I got the Ryobi but EGO just came out with one that is run off of their standard Lithium 56V battery packs! Range isn't as good as the Ryobi though. Up to 2 acres.
https://egopowerplus.com/zero-turn-riding-mower-zt4204l/
Ok… Another question. Is there an good way to survey for shade obstruction? I’m wondering if there is a Raspberry Pi script or anything out there that could monitor a panel output throughout the day. I’d like to get the optimal output from the E vs. W installation and do have some trees.
Hi @UltrasoundJelly. Good luck with the conversion! I'm sure you will get MUCH better performance out of your LifePo4's. Check the specs on your "drop-in" batteries and make sure they support series to 48V. If they do, they normally recommend you parallel them for a certain period of time to...