EricBarbour
meh
Soon I'll be into a project that will require voltages greater than the usual 48v seen in solar power. (It is an "extreme" case involving an old EV that ran lead batteries.)
The plan was to get LiFePO4 cells to make up a 30S pack for 96v "nominal" and 109v max. Maybe 100AH to start. Source TBD. (If you have some extra, sell them to me!) With the possibility of going to 32S or 35S later if necessary. There are plenty (too many) types of BMSes for 12v to 48v, but above 48v things get much scarcer and more costly. A few BMSes for 24S can be found on Ali Express but that's not enough voltage.
The Orion BMS has been repeatedly recommended to me. You realistically can't assemble an Orion for 96v, on the LOW end of their operating range, without spending upwards of $1200, not counting the cells and hardware. Plus it wants to talk to the charger over CANBUS so you "have to" get a charger capable of taking orders from the Orion. It does have the advantage of being able to control a contactor for safety shutoff. There are a few other BMS devices, but they tend to be simple cell monitors that do no balancing.
The Elithion company makes commercial EV BMSes (won't sell to me, "OEMs only", "We are unable to accept new customers due to the chip shortage") but maintain a list of EV BMSes for hobbyists on their website. Unfortunately a large number of the devices are now defunct/unavailable. Despite EV conversions being an "exploding" field, some resources are actually declining. The few that are readily available are either just monitors (the Thunderstruck/Dilithium, which isn't in that list) or are costly and complex to use (Orion, Elithion, Batrium). Don't mention the AEM EV BMS: despite still being advertised by dealers it's been discontinued.
Anyone using old Tesla or Nissan Leaf power components etc. in a conversion ends up buying one of those costly EV BMSes because the BMS in the original vehicle battery pack is "undocumented" and needs to talk to a CANBUS controller. Tesla is especially notorious for being secretive about all this. See the (few) YouTubers who did (recent) EV conversions. Warning: loads of the YT videos on this subject are posted by conversion shops trolling for business. They have zero interest in helping true DIYers.
There has been talk about the legal-liability situation being "dire"--inevitably quite a few total fools tried to use Li-ion packs from old Tesla Model S cars or homemade "powerwalls" made of 18650s, who then hooked them up incorrectly, and started a fire. Or two or three.
Yes I've seen the threads on this forum about people putting two 48v lithium batteries in series, or asking if it would work. It's just frustrating that we have this massive jump in BMS prices above 48v, as well as a greater scarcity. The electronics in all BMSs are apparently very similar, and I don't buy this stuff about higher voltage MOSFETs costing exponentially more or whatever. But I'd prefer not to buy two 48v BMSes and "play around", if possible.
Any serious suggestions would be appreciated.
The plan was to get LiFePO4 cells to make up a 30S pack for 96v "nominal" and 109v max. Maybe 100AH to start. Source TBD. (If you have some extra, sell them to me!) With the possibility of going to 32S or 35S later if necessary. There are plenty (too many) types of BMSes for 12v to 48v, but above 48v things get much scarcer and more costly. A few BMSes for 24S can be found on Ali Express but that's not enough voltage.
The Orion BMS has been repeatedly recommended to me. You realistically can't assemble an Orion for 96v, on the LOW end of their operating range, without spending upwards of $1200, not counting the cells and hardware. Plus it wants to talk to the charger over CANBUS so you "have to" get a charger capable of taking orders from the Orion. It does have the advantage of being able to control a contactor for safety shutoff. There are a few other BMS devices, but they tend to be simple cell monitors that do no balancing.
The Elithion company makes commercial EV BMSes (won't sell to me, "OEMs only", "We are unable to accept new customers due to the chip shortage") but maintain a list of EV BMSes for hobbyists on their website. Unfortunately a large number of the devices are now defunct/unavailable. Despite EV conversions being an "exploding" field, some resources are actually declining. The few that are readily available are either just monitors (the Thunderstruck/Dilithium, which isn't in that list) or are costly and complex to use (Orion, Elithion, Batrium). Don't mention the AEM EV BMS: despite still being advertised by dealers it's been discontinued.
Anyone using old Tesla or Nissan Leaf power components etc. in a conversion ends up buying one of those costly EV BMSes because the BMS in the original vehicle battery pack is "undocumented" and needs to talk to a CANBUS controller. Tesla is especially notorious for being secretive about all this. See the (few) YouTubers who did (recent) EV conversions. Warning: loads of the YT videos on this subject are posted by conversion shops trolling for business. They have zero interest in helping true DIYers.
There has been talk about the legal-liability situation being "dire"--inevitably quite a few total fools tried to use Li-ion packs from old Tesla Model S cars or homemade "powerwalls" made of 18650s, who then hooked them up incorrectly, and started a fire. Or two or three.
Yes I've seen the threads on this forum about people putting two 48v lithium batteries in series, or asking if it would work. It's just frustrating that we have this massive jump in BMS prices above 48v, as well as a greater scarcity. The electronics in all BMSs are apparently very similar, and I don't buy this stuff about higher voltage MOSFETs costing exponentially more or whatever. But I'd prefer not to buy two 48v BMSes and "play around", if possible.
Any serious suggestions would be appreciated.
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