While you probably don’t think about them until you have to, automotive batteries — the chunky boxes that helps start your car’s gas engine — are pretty terrible.
They die without warning, leaving you stranded. They weigh as much as a small child, making them tough to swap and eating into your gas mileage. They’re filled with garbage materials that are terrible for the planet.
And yet, the technology behind them hasn’t really changed much in the past few decades.
Ohm, part of YC’s Summer 2015 class, wants to change that. It’s a lighter, smarter, drop-in replacement for your existing battery.
Most automotive batteries weigh around 40 pounds, with lead plates accounting for over half of that weight.
Ohm gets the job done while coming in at just 6 pounds.
Instead of lead plates, Ohm brings in a more modern, two-part system: an EDLC supercapacitor capable of dumping enough energy to start your engine, and a set of smaller batteries (LiFePO4, which contain no toxic heavy metals) to keep things powered when the engine is off.
The physical footprint for Ohm’s battery rig ends up being considerably smaller than its lead-acid counterpart — but as they want this thing to work in existing cars without bouncing around under the hood, they’ve tucked it into a case that makes Ohm roughly the same size as any other automotive battery. (Specifically, it’s built to fit into the same cavity as a Group 35 battery)
Instead of wasting that extra space, they’re using it to bring another trick into the mix: smarts.
We all know the pain of leaving your lights on and waking up to a dead battery. Ohm’s built-in circuitry monitors the supercapacitor’s potential output; if it’s ever about to reach the point that it’ll no longer be able to start your car, it’ll just turn itself off. Your lights will fade out and the radio will go quiet — but once you turn the key, everything will spring right back to life, no jump start required.
Oh, and its lifespan (7 years) is about twice that of a lead-acid battery (3-4 years).
So what’s the downside? There has to be a downside, right?
There’s one: you can’t run your lights and/or stereo as long with your engine turned off. Ohm’s battery reserve comes in at 10 amp hours; most lead-acid car batteries come in at about 45 amp hours. If you can run your stereo with your engine off for three hours on your current battery, you’d be able to run it on Ohm for less than an hour.
Thanks to the aforementioned built-in smarts, though, you’ll never run it so long that you end up with a dead battery.
The company tells me that it’s aiming for a price point of around $200 — putting it on the high end of what you’d normally pay for a battery ($120-$180) if you wandered into your local auto parts store. Given that Ohm’s lifespan is about twice as long, though, that pricing ends up working out.
But do people plan that far ahead when it comes to things like car batteries? Many, if not most, just say “I don’t know, give me whatever is affordable and works in my car.”
With that in mind, Ohm is focusing on the performance car market first. Those are the guys that’ll rip out their passenger seats to gain a tiny performance gain on the track — so the idea of shaving another ~30 pounds off their ride is probably a welcome one.
Interested in learning more? Ohm is currently in private beta testing, with around a dozen units out in the wild. They plan to roll out crowdfunding campaign in the next month or so.