Hi all,
Some life events made it hard for me to keep up with all my activities, solar included. On the bright side, things are starting to look up.
As I’m finally getting some time to come on the forum, I’m quite amazed to see the new devices, including Elite, Handsfree and how B300K has integrated the setup of many long time users on the forum!
Adding B300K to the Office UPS
This diagram shows the latest state of the property:
- House 1 has the primary system, and feeds a second house, as well as the company office.
- A technical room connects both houses, and hosts electric boxes, laundry appliances, water boiler, and main network equipments.
- House 2 fully depends on that primary system
- The tech room also has a secondary system made of an AC500 + 3B300S + 1B300 connected to 2400Wp of solar panels. It feeds the heavy loads of both houses in that tech/laundry, and keeps the network equipment up & running 24/7.
Hello, B300K
So B300k joined the flok about 6 weeks ago, and B300 was slightly too high to fit under the desk. Sounds like a whim, but fitting seats, a treadmill and servers in a 24m² office requires some space optimization. We’re now evaluating whether the B300 should remain there, or if B300K’s capacity is enough to allow 2 desks, and a router, to operate at least 4 hours.
It seems like a “yes”, but then, we have some more GPU intensive work to do in the weeks to come, and that’ll let us appreciate things better.
B300K: Pro & cons #1: bettery energy density
- Space efficiency & energy denstity is up by +15%. Clear winner.
- B300k is 6cm lower, that brings the whole volume to 36 liters (versus B300 being 46 liters).
I didn’t think at first it would make a huge difference, but I really see the value of removing the 12V outlet, and MPPT. I don’t rely on those since we acquired smaller, and genuinely portable units (AC2A for 12V on the go, or AC70 for 60V max MPPT input on the go, or AC180 / AC240 for heavier appliances on the go).
B300K: Pro & cons #2: generally better option for AC500
Removing the extra tech positively impacts the weight, and volume
However, the point IMHO is not to compare B300k to the B300 that it replaces, but to B300S that is AC500’s default goto battery.
In the tech/laundry room: 3x B300S take the same height as 4x B300k
- B300S: About €7k and 9kWh
- B300k: About €7k and 11kWh
Clear winner here, especially considering that the price tag I used here is based on the full price, not the current discounted price (-500€ right now on the EU store!).
AC500’s column, prior to adding a 4th battery:
(my son just says: “wow it’s messy there”, yes, right).
B300K: Pro & cons #3: not really a con
I became a Bluetti user in Q2 2022. Back then, portable options were the AC200 series, and there were no sub 15kg options. AC70, and smaller units changed that. Back then, the absence of 12V would have been an issue. I’ll show why with the use of DC in a second.
Right now, I think it’s great we have an option to either maximize capacity for a given volume (11kWh instead of 9kWh speaks for itself), since I rely on smaller units for DC.
The removal of MPPT input reduces decision fatigue:
- Hey but adding 3 pairs of DC wires would allow me to use the MPPTs, and assign 3 more panels;
Seriously, no. That keeps the mental bandwidth busy.
By the way, AC60 accompanied my mold fighting marathon in October as I found huge pockets of black mold under the roof, while running 2 extra pairs of wires of the secondary systems as part of the installation of heatpumps in the buildings:
Goodbye, mold.
So, smaller units too?
Yes, and AC2A is a great addition to any a solar / portable power arsenal. In our case, AC50B was a better fit given that we run 6 servers (only 3 on that picture, before the “great rewiring” that makes things look more messy) and need them to offer 24/365 uptime. So we have a 3rd layer of UPS-ness for those “mission critical” items.
Why not just run those services in a cloud? Probably “because solar”, and the desire to rely as little as possible on centralized services we have very little control on. And mostly data privacy reasons, too: GDPR & all.
Last but not least… Why 2 main redundant power supplies?
With that “primary system” it’s worth asking: why having 2 additional solar power supplies?
Well, a recent practical case illustrates a good reason: one of the two houses hosts a yet to be identified appliance that leaks electricity. And it tripped the main 300mA breaker a few times in September and October. That means, both houses and the company’s HQ were abruplty left in the dark. Having an integrated house installation doesn’t mean that you’re fully covered. Blackouts are not an issue anymore, but electrical issues that are internal to the building can still bring the whole blackout experience. Repeatedly.
- This makes it particularly necessary to have the HQ covered with its own power system.
- The heavy loads would potentially drain the primary installation’s batteries, so the decision to use AC500 as buffer made sense here. This, especially with the price of electricity being directly linked to the peak consumption of that last month.
So after 2+ years of running a massive integrated home system, I’m still very much in favor of running within the same building a second system using Bluetti devices. While the primary system ensures the bulk of the production, the secondary systems both ensure their own functions:
- Office UPS
- Peak shaving
- 24/7 operation of servers
- Better control over heavy loads, and energy provisioning
Last but not least, we’re being struck with what we call “heavy winds” in the EU right now. Nothing close to the kind of hurricanes and typhoons experienced in other parts of the world, but the magnitude we experience here is clearly above the 100 year average. See the tree that fell and caught the wires here below - that vouched for 4 hours of blackout:
Thanks for reading, and stay tuned - we’ll soon showcase our “DIY Bluetti Handsfree leafblower”!
