Things have changed since you ordered batteries. I placed my order in the group buy February 11 and they have not shipped yet. I'll be lucky to get them by July.Depends on your time frame. The group buy here in the forums for 270-300ah LFP cells is place to start. The cells are drop shipped from china and Michael has said he can order any number of ah ranges (including 100-120). I ordered my 280's through him and he was great to deal with. Shipping over the holiday last year took right at 60 days.
Lishen 270ah-272ah cell group buy.
Ok, this will be a longish post but I want to lay some foundation before taking orders on these cells. Eve 280ah cells appear to only be available at this point from suppliers that want a premium price for them From everything I can find, Lishen is extremely popular in China but has yet to get...diysolarforum.com
Ryobi Zero-Turn Mower SLA to LiFePo4 Conversion - (Updated - Build Complete With Pics!)
- Thread starter AMDPower
- Start date
Austan
New Member
- Joined
- Jul 23, 2020
- Messages
- 45
That's true and I am in the same line waiting. He did however mention purchasing quite a few 150ah's that were ready for immediate shipping if I remember correctly. That's probably the direction I would look first before buying through Ali.
Like I said before, if the output works, 16 could fit the bill nicely and at/under budget, and if the space is available and the op wants the longevity, 32 would give more output and could be made to last longer.
schmism
Solar Addict
another option is to control a disconnect relay and wire the motor directly to the relay. Then you dont have to have a high current BMS to pass 200+ amps to the motor. and instead just monitor battery voltage and trigger the relay when H/L Vco.
This is what http://www.electrodacus.com/ does. However they only support 8s at the moment. Its my understanding that some of the Daly BMS can also be used to trigger the right kinds of relays for this kind of setup.
This is what http://www.electrodacus.com/ does. However they only support 8s at the moment. Its my understanding that some of the Daly BMS can also be used to trigger the right kinds of relays for this kind of setup.
AMDPower
New Member
- Joined
- May 18, 2021
- Messages
- 123
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 looks like I'll need 3.2V 100AH cell. I think a 100A 48V BMS should suffice. Can it survive a couple second peak above 100A in worst case scenario? It likely won't even get that high with LiFePo4 batteries though as the voltage should be more stable. 100A draw happened when voltage dipped down to 44V.
Most 100A bms have a surge ability over 150
You could build a custom box, or purchase 4 marine battery cases
Austan
New Member
- Joined
- Jul 23, 2020
- Messages
- 45
First you are going to want to know the size of the cells you choose, then determine how many you will group together, then find/make a box that size. For instance, here is an image of 16x 135ah cells in an 8x2 configuration. This layout measures 13.5" wide and 15.125" long, and 7.25 high (plus wiring on top). These are 135 amp hour cells, 100's would take up even less room. I just didn't have the 100's already in a file so I used what I had. It also depends what you buy as some are tall and narrow and some are short and wide.
AMDPower
New Member
- Joined
- May 18, 2021
- Messages
- 123
After looking into building my own and the cost, I think I may end up going with the 100AH Ampere. Four of these would be 48V at $2000. It would provide plenty of current and is plug and play with the existing battery storage. Given that four new SLA batteries would run me $700, it seems like a no-brainer. If my calculations are correct, it likely would last the life of the mower if I well maintain them. Building my own wouldn't save me much from what I'm thinking.
Does that seem to make sense? $499 for 12V 100AH with a 100A BMS (280A peak) sounds pretty reasonable right?
Does that seem to make sense? $499 for 12V 100AH with a 100A BMS (280A peak) sounds pretty reasonable right?
Last edited:
Austan
New Member
- Joined
- Jul 23, 2020
- Messages
- 45
That 280 peak is only for 5 seconds so if you pull over 100 amps going up a hill, you might not make it all the way to the top. That said, I believe you took some readings and came to the conclusion you wouldn't be pulling over 100 anyway even up hill. Worst case scenario is you do not mow on the way up, just on the way down if it comes to that. So yes, those batteries look like they will do what you want.
I'm the type who like projects and since I have sourced from China before, I do not mind spending a lot of time asking questions and getting quotes. I would expect to pay less than 900 for 16 cells delivered with a bms for another 150. To me, it's worth the money difference but I completely understand those whose time is better spent to them doing something else.
BTW, it's really cool that you have an electric zero turn. I didn't know there was such a thing until your post.
I'm the type who like projects and since I have sourced from China before, I do not mind spending a lot of time asking questions and getting quotes. I would expect to pay less than 900 for 16 cells delivered with a bms for another 150. To me, it's worth the money difference but I completely understand those whose time is better spent to them doing something else.
BTW, it's really cool that you have an electric zero turn. I didn't know there was such a thing until your post.
If you need 48v, then get or build an actual 48v battery. Some manufacturers are OK with series connecting their 12v LiFePO4 batteries, some aren't.
I doubt that the 280 Ah cells will fit your compartment, but just for comparison, I bought eight 280 Ah cells (including shipping, taxes, fees) for just over $900. That's 2.8 times the capacity of a 100 Ah cell for about the same money you're looking at in an off-the-shelf battery.
If it was me, I would max out the available space in the compartment with the largest cells I could buy.
I doubt that the 280 Ah cells will fit your compartment, but just for comparison, I bought eight 280 Ah cells (including shipping, taxes, fees) for just over $900. That's 2.8 times the capacity of a 100 Ah cell for about the same money you're looking at in an off-the-shelf battery.
If it was me, I would max out the available space in the compartment with the largest cells I could buy.
Austan
New Member
- Joined
- Jul 23, 2020
- Messages
- 45
Great point. I had forgotten that some of the pre-builts do not handle being wired in series. I'm also in complete agreement with the rest of what you said.
Edit to add: 16x280's in the above configuration would measure 23"x14"x9 high if you are wondering if it would fit in the amount of space you have available.
Additional add: the batteries OP linked to can be wired in series up to 48v.
From the reviews-
"Q: Can this battery be wired in series for 24v applications?
A: Yes. This battery can support wired in series for 24V application;
And This battery can support maximum wired in series for 48V applications, if you have demands on 48V, you can wire 4 modules in series to support 48V."
Last edited:
AMDPower
New Member
- Joined
- May 18, 2021
- Messages
- 123
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. I'm cutting 1.25 acres of grass and that will likely get me cutting 4 acres with 100AH Lithium. I also can't wait until mid-summer to get the batteries. I briefly looked at 120AH cells from AliExpress (recommended by Will on his site) that could ship from US but I'd be at $1700 just for the cells. And then I'm not sure what to build the box out of. Is it OK to use Wood? Really, capacity above 100AH does nothing for me. $900 for cells sounds good for cells but how long would that take to receive?
AMDPower
New Member
- Joined
- May 18, 2021
- Messages
- 123
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.
egopowerplus.com
POWER+ 42” Z6 Zero Turn Riding Mower
The EGO Power+ 42” Z6 Zero Turn Riding Mower produces Power Like No Other ZTR out there, gas or cordless.
egopowerplus.com
On a mower, I would be reluctant to build a box out of wood. Aluminum perhaps.
45 days is about the average shipment time frame from China by ocean freight. Less if you choose air freight.
AMDPower
New Member
- Joined
- May 18, 2021
- Messages
- 123
Hmm... Maybe I can limp along for a while until they arrive. I found these for a very reasonalble $1060.56
www.aliexpress.com
546.0US $ |Lifepo4 NEW 3.2V 105AH Lithium Iron Phosphate Cell 12V 24V 36V 48V DIY Rechargeable Battery Pcak High Capacity EU US Tax Free|Rechargeable Batteries| - AliExpress
Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com
Q-Dog
¯\_(ツ)_/¯
You might be able to find some off-the-shelf battery boxes to contain/protect the cells.
I would be tempted to build a metal or fiberglass box to replace the existing battery tray. It all depends on how much space there is and how much I like the existing set up. Since you are replacing heavy lead with something less heavy, the weight of a metal box may be insignificant
I would be tempted to build a metal or fiberglass box to replace the existing battery tray. It all depends on how much space there is and how much I like the existing set up. Since you are replacing heavy lead with something less heavy, the weight of a metal box may be insignificant
Austan
New Member
- Joined
- Jul 23, 2020
- Messages
- 45
Another way to go about it is to look on alibaba for what you want and then contact supplier and request a quote for door to door pricing (DDP) to your location. The prices are regularly better than aliexpress.
By the way, what are the dimensions of the battery compartment?
By the way, what are the dimensions of the battery compartment?
In the meantime to get you through some mowing -- have you ever thought that your existing agm's are out of balance, and may have been charged badly by the mower itself? Did they sit on the mower's charge circuit and cook, or did you leave them uncharged for 6 months at a time...
Have you considered charging each one individually with a charger that has an agm-setting externally to the mower's own circuit - at least once to make sure they get a true full charge and are in as much balance as they can be? Look for faulty / corroded / loose battery connections.
It's stuff you can do now to get you through, prior to your conversion.
Have you considered charging each one individually with a charger that has an agm-setting externally to the mower's own circuit - at least once to make sure they get a true full charge and are in as much balance as they can be? Look for faulty / corroded / loose battery connections.
It's stuff you can do now to get you through, prior to your conversion.
Similar threads
