Electric railway mechanic here. This is a bad, bad idea.
Higher voltage DC is a mean drunk.
Here's a nice arc display from an inherently current-limited source - series-connected solar panels.
Here's about twice your voltage. Note the car is energized the whole time, and the arcing restarts - twice!
That could be your house.
AC crosses zero volts and zero amps 100-120 times a second. That is extremely useful for snuffing arcs. Inductive loads resist changes in current and will spike voltage to do so, and if they're doing that across a switch, in a few milliseconds it will be up against an opposing current.
Whereas in DC, absolutely nothing stops an arc. It can’t be bargained with. It can’t be reasoned with. It doesn’t feel pity, or remorse, or fear. And it absolutely will not stop, ever - unless you kill it or it destroys its own current pathway.
Like that poor tram.
Arc detection and suppression
If you ever have unhooked speakers "live", you're heard the crinkle-crunch sound of arcing (the waveform is the same on the wire). Better trolley substations have a "Rate of Rise" detector (AFCI basically) to use digital signal analysis to "listen" for that "sound", and trip power. You need something like that. The Odessa tram system didn't have it, as you can "hear" from the audio.
Now, on trolley cars, DC switches (even for small loads like a vestibule light) have two essential parts. First, the switch has a "snap" mechanism that throws the contacts far apart when they open. Second, there is a "blowout" mechanism that re-directs the arc into an "arc chute", made of ceramic or hard-board asbestos. The blowout is typically 2-3 turns of magnetic coil; the collapsing magnetic field pulls the arc into the chute.
So you need your switches and circuit breakers to be rated for interrupting DC. Your breakers need to be rated to interrupt a bolted dead short - AC power breakers are typically rated 10kA or 22kA. Further, you need a disconnect switch! You can't rely on pulling the plug, because if the fuse in a British plug blows, it will just arc across the opened fuse, and much like the poor tram, burn up the plug entirely, and even spread the arc to the melting socket. At which point you'll never get it out.
You see in Peter's video here (from comments).
DC ratings are much lower on average equipment
And if you read your equipment's spec sheets, you'll see that their DC ratings are lower than AC by as much as 90%. This is because of the sheer difficulty of snuffing a DC arc. For instance a switch rated 250V might be rated only 28 volts DC.
I remember seeing a light rail vehicle where they just could not obtain a 700VDC rated contactor. They used a 3-phase contactor rated for 2000VAC and wired all three phases in series.
Rearrange the battery pack for a lower voltage.
Split the pack and re-stack it in series-parallel for a lower voltage. Aim for voltage around 36 volts, although you'll be limited by the sub-pack sizes of course. Don't go much over 48 volts, even that is starting to head into DC's dark side.
Anything you do with DC of even 36 volts needs to be properly BSI/TUV/UL listed equipment. None of that "cheap Chinese" stuff, get gear from quality electronics supply, or use AC mains gear that is cross-rated for DC. For instance Schneider rates some of its consumer-tier lines for DC up to 48V (120V available on specialorder).