Has anyone ever added a quick battery selection switch? After searching a bit for high amperage capable switches I ended up discovering boat switches, which seem to fit exactly what I’m looking for:
My idea is to build a few 2-3S packs, each with their own BMS so they can be recharged individually. I’d just add a female XT90 port to the board and booster pack, and use a male to male XT90 to connect the 2. Then wiring a switch like this into the board, with the default enclosure battery as battery 1 and external xt90 port as battery 2, I should then have the ability to equalize the voltages of the board and an external, and run them in parallel, or, just toss a fresh battery on top and switch the board over to just using it. I think my biggest complaint is that switch is fairly large, so if that’ll work, I want to find a smaller one
OP this is a really clean solution for higher amp applications.
I used a SPDT switch on an old scooter for my son that switched between 24v and 36 volt liion packs. He called it boost mode. I thought of it more as a limp home, reserve pack. I wanted to use it again on a board but couldn’t find ones high enough rated on the voltage or amps to feel safe. XT90 loopkey is the cheap and easy choice.
Coming from the guy who got home, house key in hand, dog licking the face, spouse asking questions, sets the board down, grabbed the charge cord, and stuck the house key in the charge port…
I can’t agree more. Last thing you need is a battery fire caused by misplugging a loopkey while you’re in the middle of a huge ride and really far away from home.
Trying to keep everything sleek as possible, What I’m thinking now is just a couple mounted XT90s, but I’ll 3d print some attachments for the male loopkey/external battery side so that both ports need to be open for either to plug in. Basically just a long piece of plastic with a dummy connector on the other side, so I can’t physically plug in both at the same time
It does limit my ability to run both batteries together, but also… ehh, not a big deal
Maybe you could take an MR60 and modify it so it can be turned either direction while plugged in. And then make it a loop key on only 2 of the 3 pins. So you pull it out and turn it the other way to change the battery. That wouldn’t be anti-spark though so you’d still need a separate XT90S
Two loopkeys are a lot more reliable than the switch. I built a setup for a customer like that as he has two identical 12S5P batteries and wanted to use them together for longer rides. In theory he could also plug in two loopkeys at the same time and run them in parallel with all the benefits and risks of doing that.
Which could work, although it also gave me another idea. I can drill a couple sets of 2 holes, and run the power to the esc straight though the deck, terminated to a xt90-s/qs8 above the deck. Maybe throw some bullets in line below the deck in case I have to remove it for whatever reason at some point.
The battery can then be ran the same way, so when I’m not using an external battery, I just have the connection on the top of the deck. Should be easy enough to get the wire lengths right to keep it as flat as possible. Connecting an external battery would then just be swapping connectors, and the male/female will idiot proof me plugging the wrong thing in. I could also get a parallel adapter if I did want to run both at the same time, but would be left at home where I’m sure to triple check myself before using it
The reason I’m thinking of running the cables through the deck and not just a connector is that this will be for a lacroix nazare deck/enclosure, so not really a lot of room in the battery compartment for vertical wires hanging down. If I aligned it just right I probably could, but also, I can keep the connectors more flush to the deck doing it this way over having a connector face mounted. Running it through the side is also an option, but I’m not sure how I feel about that one. Seems like it would be harder to keep clean
This is the problem, there should be no way to connect the switches to cause “battery fire mode” and it’s why using two batteries is so hard. That setup is really dangerous. (unless it’s fused)
Yeah that feels like a bit more of a downgrade over a rigid connector. Unless I were to make some custom housing and mount 3 to the deck with precise spacing, but that sounds like a bit too much room to screw something up
