Ok, so here is what I'm looking at for V2:
Main DC Buddy Base v2
- 2x 24V in
- Input current measurement per input port
- 4-8x 24V out, on/off control, same voltage as from input
12V Board
- Stack-able to the DC Buddy
- 12V, 5A, 4-8 ports, controllable on/off
5V Board
- Stackable to the DC Buddy
- 5V 5A, 4 ports USB, controllable on/off
DC Battery Buddy
- 24V in
- 12-36V battery port (targeting LiFePO4, 1-3 batteries in series)
- 12V-36V out (on battery or off, can select different output voltage when on battery, otherwise its pass through)
The bidirectional nature is all thanks to the highly integrated
https://www.ti.com/product/BQ25756 - massively simplifies things for lots of flexibility.
Note:
The design has been modularized a bit. By default, you get a 24V only board. 12V and 5V and 36V boards simply stack on to the PCB and extend the case.
Original notes left below:
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This leaves a few open questions:
The 36V question:
Most pumps are 24V (Vortechs, Gyres, DC skimmers, etc), except for some return pumps (Vectra, etc). The EcoTech pumps can run on 24V in backup mode, but others on the market may not. Making the base system run at 36V and providing 24V adds complexity/cost for the 1-2 36V pumps someone may have - is it worth it?
Option B is to run a boost converter from 24V to 36V for 1-2 ports, including in backup. But again, cost/complexity for something most people don't need, but less and could be made a modular option more easily. Personally, I have two Vectra pumps - one is a return one is a accessory closed loop to the garage.
The 5V question:
How many devices actually need a 5V supply? I have a handful, but not sure really how common this is. Maybe a stackable option makes sense like the 36V boost output.
The controllable ports:
The main intent is to be able to turn things off when you switch to battery, or cycle them to extend runtime (e.g., 10 min on, 10 min off, or similar). Is something like a programmable feed timer useful? Remote control?
Pricing? Too hard to tell yet, but this isn't a $50 box unless you just want a straight voltage passthrough. Each different voltage probably adds at least $20-30 end cost.