I believe I’ve finally cracked a cheap way to charge this vehicle.
I came across a fantastic deal on a 72 volt 12 amp QuiQ charger, $100+ $50 (it’s shipping from Canada). And they have ‘Best offer’ enabled, so I might get it even cheaper. It’s compatible with both 110 volt and 240 volt power, which is perfect. I am unsure if I’ll be able to install a 240 volt outlet at my home just yet, but the ability to charge quick at a charging station, like the one down my street, really excites me. It makes it a more polished and realistic set up.
Over time, I plan to get this car up to the full 144 volt pack that I want in it, but to start, I think it’s more manageable to work at the 72 volt level. Interestingly, this gives me a great upgrade path. By going this route, I won’t have to change anything in the future and avoid potentially wasting money on items that I would remove later.
My plan in the future is to have two sets of 6 – 12 volt batteries, one in the front and one in the trunk, to help balance weight and achieve the 144 volts we want. And this works out better than I had expected with this charger. What I want to do at this stage is add a third contactor, but this one is in the middle of the cable connecting the rear and front packs together. The QuiQ charger has a 12 volt out, so not only can I charge the accessory battery, but I can use that to power the contactor and disconnect the battery packs when they begin charging. Effectively making two separate 72 volt packs. Perfectly within reason for these chargers to refill with ease. And actually quite quickly. At 12 amps, that means they’re doing about .864kw. Not a ton, but when put into perspective of one of these packs (72v * 12 batts * 125ah * .5), it’s about 4kw, charging at .864kw/h, or 4.5ish hours.
And if we want to calculate for normal home voltage (110 volt), the charger reduces slightly down to 10 amps. So then it’s 4kw / .72, or 5.5 hours. That is still more than manageable, I’ve taken naps longer than that.