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> that could be assembled cheaply in a makerspace from off-the-shelf components, an Arduino-class microcontroller, and a PROM. Excuse me? You can get off-the-

by amluto 3y ago

> that could be assembled cheaply in a makerspace from off-the-shelf components, an Arduino-class microcontroller, and a PROM. Excuse me? You can get off-the-shelf batteries (although LFP batteries with real BMSes are not actually interchangeable, sadly). But you also need the power electronics, and you should not be doing that as a DIY project unless you really know what you’re doing. I would look to the off-grid/RV space for disruption. For example, here’s a “portable power station” for $600. It costs about 2x as much as a random 1500VA APC UPS I looked it, except that it can deliver twice the actual power (if your UPS is powering a modern power-factor-corrected PSU, you just need watts and the VA isn’t a big deal, and APC is cheating their specs by including unnecessary reactive power capacity in their headline number) and 20x the energy storage and thus runtime. APC tries hard to obscure very low capacity of their batteries. No one will buy an off-grid setup that can barely power an espresso machine long enough for a single shot.

earleybird 3y ago
I'm running a Renogy inverter/charger 2000W with a single 12V 100Ah LiFePo battery that run 3 Odroid H2's (Proxmox cluster 1), 3 Beelink's (docker swarm cluster) and various switches and ISP device. There is also a dual gpu desktop that pulls 400-450 watts when running folding at home. It will carry that load for 6+ hours from an 80% charge which is were I keep it for long term battery health; though I do shutdown the dual gpu if the power is out for more than a few minutes. The Renogy will pass 'shore power' directly through and switch (purportly) in <10ms although I'm not confident enough that it is quick enough (1/2 a cycle at 60hz) so I run the standard consumer ups downstream. I'm using a pretty stock RV circuit layout. The one thing I did do is limit the max charging amps to 20 to ensure that the charging load plus the working load stayed well in the capacity of the 110V/15A line. I did try a Bluetti 3BA but it never worked as expected; ie it would cut out at unexpected times and firmware updates are problematic.

by amluto 3y ago

earleybird 3y ago

I'm running a Renogy inverter/charger 2000W with a single 12V 100Ah LiFePo battery that run 3 Odroid H2's (Proxmox cluster 1), 3 Beelink's (docker swarm cluster) and various switches and ISP device. There is also a dual gpu desktop that pulls 400-450 watts when running folding at home. It will carry that load for 6+ hours from an 80% charge which is were I keep it for long term battery health; though I do shutdown the dual gpu if the power is out for more than a few minutes. The Renogy will pass 'shore power' directly through and switch (purportly) in <10ms although I'm not confident enough that it is quick enough (1/2 a cycle at 60hz) so I run the standard consumer ups downstream. I'm using a pretty stock RV circuit layout. The one thing I did do is limit the max charging amps to 20 to ensure that the charging load plus the working load stayed well in the capacity of the 110V/15A line. I did try a Bluetti 3BA but it never worked as expected; ie it would cut out at unexpected times and firmware updates are problematic.