We have one of the original electric cars, from before the War... WW-1, that is: A 1912 Baker Electric.
- Westinghouse 5.9 HP, 48-volt Series-wound DC motor
- 56-volt nominal, 40-cell Edison battery (nickel-iron)
- ~250 mile range on original battery pack
- ~25 mph top speed
- Resistive-mechanical-quadrant speed control. 5 forwards speeds, 2 reverse
- 2-wheel brakes
- Shaft drive
- Tiller steering
It's the same model Jay Leno has - Google "Jay Leno Baker Electric" for some photos and videos. His one is shinier than ours, has a better interior and has nicer headlights. Otherwise very, very similar.
Our car currently has ten 12-volt flooded lead acid batteries configured as two 60-volt strings, which are, not to put too fine a point on it, rooted. I've been thinking about replacing them for a couple of years, they've finally completely died so I can't put it off any further.
The plan is to replace the lead-acid batteries with LFP cells, probably 60-volt nominal (20 cells).
Peak current requirement is only about 100 amps, sustained is more like 30-ish. In theory you could pull about 90 amps sustained, but in practice I've never seen it while we've been pottering around.
The car has front and rear battery bays, I'd like to use the front one as a "Frunk" like a Tesla and put the shopping / picnic in it. Batteries, charger, etc go in the rear compartment. Rear bay is about 600mm square, almost 400mm high.
Cell size looks like prismatic cells from 40 AH and up will have more than sufficient current capacity, but the 60 or 90 AH cells might be a nicer fit in the bay (should go ten deep - I'll check the measurements).
I'd be happy with an 8-10 amp charger, I don't care if it takes all night to charge, it isn't an everyday vehicle. 600 watt chargers also seem to be dirt cheap (under $200) and high-power 60-volt chargers seem to be hard to find anyway.
The hard part seems to be a motor controller. I'd like to bypass the resistive speed controller it currently has. For starters, the control handle seems to be sitting at pack voltage if the tingling I get is an accurate sign. Second problem is that the lowest speed is unreliable verging on kaput. Third is that it has 4 fixed "speeds", rather than smooth progression. Fourth and maybe worst: Unless you're driving flat out it's dumping amp-hours into a resistor!
All that said: It's a series-wound motor. So I need 100+ amps at 60 volts, DC PWM, with reversing of one field (either the armature or the field coils, not both). That's currently done mechanically by the speed controller. Open to suggestions for a speed controller - it seems to fall between "e-bike" and "e-car" in power terms - 6kw seems to be an odd size, but I'd prefer not to pay the extra $ and space for 20kw+++ controller.
I've heard that some PWM DC controllers can also supply 12v. I need a few amps to run the lights, nothing significant: It just has blinkers and a couple of stop lights that will be converted to LED. Head lights sort-of exist, but will probably have LED spots put in them in order to actually produce some light. The bell (think "tram bell") runs @ pack voltage, so it really is just the lights. The blinkers aren't original, and I'll likely convert the single tail light into a pair of brake/tail lamps.
Instruments is a dual reading volt/amp gauge: -50 to 150 amps, 0-100 volts. I'd like to add an inconspicuous power meter.
Last point: I don't need to comply with NCOP 14, the car isn't a conversion. In fact, I don't have to comply with any ADRs at all, because the car pre-dates them. However, I would like to avoid electrocuting myself. Current packs just have manual switching, but I could be convinced to add a contactor if it was cheap. There's no point worrying about restraining the battery pack in a collision, the car is mostly made of wood and huge amounts of non-safety plate glass, with no seat-belts. If you have an accident, the battery coming loose would be least of your problems.
Advice wanted on:
- Battery size
- Motor controller
- Power meter[/i]