I never heard of REC BMS before, Nice!REC BMS supports up to 128s
The cheapest way is to buy a complete crash Model 3 with 60 kWh LFP battery and sell all other parts to recover your initial purchase.I would be interested to try a used EV battery - if I could find one for cheap near by.
To build a 360V battery from LiFePO4 cells would mean 112 cells
There are several in the EV conversion space. The two I fam mentionon earlieer and am familiar with are Orion and Emus. Upthread someone else mentioned REC can go that high.But I don't know where to find a 112-S BMS.
Why? I don't understand why you don't group 7 cells in parallel to create a single 2128Ah cells and then put 16 cells in serie.I can imagine a 112-S, 304Ah cell LiFePO4 pack - even if the BMS is $800, you would only need one to build a 109kWh battery, my current 53kWh ESS in 48 volt is using five BMS's, and to expand to over 100Ahr will take four more, costing a lot more than $800 for similar capacity.
You can be this guy. Simply buy 112 cells 18650 for less than 100$ ?Although...I can think of someone (WP) who likely Does have 112 cells laying around...
I can imagine a 112-S, 304Ah cell LiFePO4 pack - even if the BMS is $800, you would only need one to build a 109kWh battery, my current 53kWh ESS in 48 volt is using five BMS's, and to expand to over 100Ahr will take four more, costing a lot more than $800 for similar capacity.
You are correct, the REC is based on 16S modules each with it's own BMS controlled by a Master.
To achieve 112-S, this system would require 7 modules of 16-S plus the master controller. The control and details available in the REC are very impressive, they have some short video clips on their website that provide a quick overview. Costs would be in the $4500-5000 range.
The Orion and EMUS. Still digging into these units.
Orion has large cell count BMS in multiples of 12, from 24S to 168S - no 112S, would have to choose either 108S or 120S.
MSRP for these is about $1300USD. More research underway, there is a lot to review.
The Orion is centralized and they allow you to wire them for fewer cells. For example the 120S unit can handle 109 to 120S.The Orion and EMUS. Still digging into these units.
Orion has large cell count BMS in multiples of 12, from 24S to 168S - no 112S, would have to choose either 108S or 120S.
I didn't realize Heltec had these. interesting.Same here: https://m.aliexpress.us/item/3256804396944825.html?spm=a2g0n.detail.1000014.6.39e4Kc3MKc3MM1&gps-id=platformRecommendH5&scm=1007.40000.326746.0&scm_id=1007.40000.326746.0&scm-url=1007.40000.326746.0&pvid=0ea844ad-1608-4612-968a-68fbd79b8dc9&_t=gps-idlatformRecommendH5,scm-url:1007.40000.326746.0,pvid:0ea844ad-1608-4612-968a-68fbd79b8dc9,tpp_buckets:668#2846#8112#595&pdp_npi=3@dis!USD!435.0!435.0!!!!!@2101c67a16818756174392546e1904!12000029714860867!rec!US!135507165
122S for $985
or 120S for $904
or 103S for $870
or 100S for $835
Yeah, in 18650's or 32700 (e-bike stuff) I DO have enough cells, but not really what I was after, LOL, then again I would only need 92 of those cells to get to 360v LOL!!Why? I don't understand why you don't group 7 cells in parallel to create a single 2128Ah cells and then put 16 cells in serie.
And if you want more output power (amps) out of your BMS, simply use a relay BMS. Here an example with 15 kW capacity (300A x 51V): https://batteryhookup.com/products/7s-21s-24v-75v-300a-lithium-ion-bms
You can be this guy. Simply buy 112 cells 18650 for less than 100$ ?
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Haha! Yeap, super useful battery. Can power the house in the morning and go shopping lumber to the Homedepot in the afternoon ?What did you call that one you have? oh yeah the "battery on wheels in the driveway"
No, there are LFP cells, so you need 112S. Generally, 360V EV battery pack are 96S when there are not LFP cells.Yeah, in 18650's or 32700 (e-bike stuff) I DO have enough cells, but not really what I was after, LOL, then again I would only need 92 of those cells to get to 360v LOL!!
For 16k$ you can clearly have a complete 60 kWh or 75 kWh crash Tesla 3 to build your dream. What do you think about a 300-400 hp electric B2000 ??About $16,000 for a DIY LiFePO4 100kWh 360vDC battery pack.... or my other wild dream idea, an EV conversion from a 1987 Mazda B2000 mini pickup truck.
My thoughts on this:Back on subject, what is the advantage of an high voltage battery for you instead of a regular/safe/easy to build 48V?
I wrote to Emus and there engineering tech replied very quickly with some points and questions. I am interested to see what they can suggest and how their system would compare with the Orion, both the technical capabilities, and cost. This is an interesting direction I never thought of when building the 16S packs.The Emus is decentralized with a central control box and individual sending units on each cell which are networked. I have had a good experience with both.
I think both EMUS and Orion have specific products designed for the 16S segment. Because the larger systems typically are used in EVs the 16S versions do not have all the various interfaces usually found in EV conversions. Some of those are J1772 EVSE interfaces, Limp mode for inverters or motor controllers and CAN communications with chargers and displays.This is an interesting direction I never thought of when building the 16S packs.
I have this kind of versatile battery for the wood chipper, the snow blower, the cargo bike, the chainsaw (backpack), the mower, but it's at a reasonable 52V (14S NMC).can fit into an off road vechical, and or a farm tractor, and or a house boat,... could this not be a super versatile modular power system
Well, despite if you skip the official CCS combo protocol for charging in DC you will still need a kind of powerful DC-DC converter.If the EV and ESS are both 360vDC, this would very much simplify rapid charging the EV, or the ESS, without expensive commerical DC chargers required, only control over the current flow.
3 points:(for example) and has say a 160 mile range, but an additional identical voltage and chemistry battery pack is available, that can fit into the truck box, be secured and plugged in when longer range is needed, increasing the truck range to 320 miles wouldn't this 'modular' battery
An EV is way more than battery/motor/controller. Charge port, heater, charger, DC-DC, connectors, cooling pump/devices, brake booster, accelerator, power steering, etc.I could source a wrecked EV and reuse it's battery/motor/controller and I likely will go this route
Good point. At my age I have to pass water every two hours. If I do that at a Supercharger, by the time I find the urinal, get my zipper open and some flow, then take the time to empty my bladder, and then make sure my pants are zipped, my Tesla has another 150 miles of range.2-Don't underestimate fast charge stations and your need to stop each X hours for lunch, for break, to pass water. There is more and more charge station everywhere and it's kind of tough to be at more than 100km of a charge station those days.
I agree. That is why my one and only EV conversion was a 1973 VW which did not have any computer interfaces so all I needed was a battery, motor and controller. Also I needed an adaptor plate and a shaft coupler so the motor could bolt onto the transaxle without needing motor mounts. It was a perfect EV for local driving in my small beach town. It could also legally go on the state highway that went through the middle of that town compared to the expensive golf carts that several people drove around town and were limited to 35 MPH at the most.An EV is way more than battery/motor/controller
Not at att. Attracting members such as yourself to take this thread to new levels was exactly my intent when I started itMy apologies to @fafrd very interested in this topic, didn't mean to be a hijacker of the thread!