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Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

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Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#71

Post by blueintegral »

NateLawson wrote: post #11
blueintegral wrote: post #2

Hey everyone! I'm Hunter, one of the cofounders of Ohm. Let me know if I can answer any questions.

I don't know how much you can talk about the tech, but I'm interested in how it fits with existing batteries & applications. Is it possibly an add-on to lead acid? A better jump starter? What about industrial like large motor plants where you need a jolt to get a lot of weight moving?

Actually, our very first prototype was a thing that sat on top your existing car battery. After talking to some people, it seemed like they preferred it integrated into the battery itself. It makes the price easier too, since you're not spending money on a battery AND a thing you put on top of it, just a better battery.

Industrial motors aren't something I've looked into a lot yet, but it could be interesting. I was just talking with someone the other day about using supercaps in robotics applications. Apparently some people are already putting small supercaps in the joints near the motors to help provide surge current during high accelerations or loads.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#72

Post by kevin_thibedeau »

>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

Hope you don't plan on selling in the US because this behavior is going to get you sued into oblivion by the family of whoever ends up dead because the lights turned off abruptly on a vehicle with a faulty charging system.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#73

Post by blueintegral »

chrisBob wrote: post #35
daniel-levin wrote: post #23

Earlier quoted context omitted.

>> Rated for -30°C to +50°C [1] -22F ~ -30C [1] http://www.getohm.com/

Is that expected to be sufficient? Typical automotive electrical components are rated over -40C to 85 or 105C. I think the engine compartment is typically hotter than 50C when a car is running. This might be more suitable to a car that mounts the battery remotely: I have seen BMWs with the battery in the trunk.

We're being conservative with the temperature rating for now. The components are rated better than that, but we're still running cycle tests in our temp chamber and waiting to get the system tested by an outside lab.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#74

Post by sandworm101 »

blueintegral wrote: post #65
sandworm101 wrote: post #61

Earlier quoted context omitted.

Glad to see you are on top of the voltage/fire thing. But I still see these things as non-recyclable in comparison to industry-standard lead-acid batteries. I can drop my current battery off at any number of garages without issue. Once this new device inevitably breaks down (anything under a hood will eventually) it seems like just more e-waste.

Yeah, we're still figuring out the best way to handle collecting the units at the end of life, but there's already places like this that we can send them to and keep it from turning into e-waste: http://www.kinsbursky.com/

You might want to add language re battery orientation. It looks like your device doesn't care about up and down. That's a big deal for car people. They pay extra for a 'dry' battery that can be mounted in weird places and angles. And mention venting or lack thereof. That's another sticking point for people shopping for aftermarket batteries.

Also, vibration testing if you have done any. Custom cars and offroad machines shake. Nobody wants a battery with internals that look like they might break loose.

If you really want to sell a premium battery, create a motorcycle model. Sportbike owners are really into weight reductions and eat through batteries. It might as simple as a smaller plastic shell.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#75

Post by conjecTech »

sandworm101 wrote: post #47
morcheeba wrote: post #41

Earlier quoted context omitted.

I don't get your (4). It's a capacitor + lithium battery. It's got to be nominally 12 volts, or else it wouldn't work in a car. Capacitors only charge to the voltage you apply -- in this case, 12v. I'm not sure if you mean voltage by "beyond that", but fire risk isn't really correlated with voltage - more with chemistry, energy, and fusing. As for (5), they clearly care about cost.

I was thinking about the internals. They might have components with higher potentials that are then regulated down to 12v. In a crash, those could be a source of high-voltage shorts that might be a source of ignition.

No worries there. Everything is right around the 12V level. We can boost the voltage on the capacitors some, but we never exceed anything that the alternator is spitting out.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#76

Post by heywire »

CamperBob2 wrote: post #58
blueintegral wrote: post #50

Earlier quoted context omitted.

You're right! Lead acid car batteries are one of the great recycling success stories. What's interesting is that the volume of lead acid car batteries in the world is so high, that even at that high recycling rate, that still leaves 24 million pounds of lead each year from car batteries that don't get recycled. There's also been some problems recently with lead recycling plants contaminating the environment [1]. You'…

Some thoughts: The price point is impressive if you can sell at only ~$50 more than a standard lead-acid battery. If pressed to find a flaw, I think the biggest is one you've already identified: 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…

>Nobody with a modern car or SUV is going to get three hours' runtime for their accessory equipment.

Really? I've left the satellite radio playing for hours in my 2011 Hyundai Sonata at moderate volume with no hint of problem starting my car afterwards. It has the premium sound system (including subwoofer) and navigation.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#77

Post by maxerickson »

NateLawson wrote: post #11
blueintegral wrote: post #2

Hey everyone! I'm Hunter, one of the cofounders of Ohm. Let me know if I can answer any questions.

I don't know how much you can talk about the tech, but I'm interested in how it fits with existing batteries & applications. Is it possibly an add-on to lead acid? A better jump starter? What about industrial like large motor plants where you need a jolt to get a lot of weight moving?

You can buy Lithium ion jump starters on Amazon today:

http://www.cnet.com/news/pocket-sized-jump-starters/

(linking the review because I don't know which brands are reasonable...)

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#78

Post by blueintegral »

ebbv wrote: post #19
blueintegral wrote: post #2

Hey everyone! I'm Hunter, one of the cofounders of Ohm. Let me know if I can answer any questions.

How many times in a row is the battery able to start the car without needing time to recover?

It varies based on the specific car you have, but the short answer is "several". We've been measuring the current needed to start a bunch of different cars, and the results are pretty varied (based on temperature, engine compression, size, etc). One of our testers often needs a couple of starting attempts on his car and it sometimes takes him 3-4 tries before it starts with Ohm.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#79

Post by logicallee »

kevin_thibedeau wrote: post #72

>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 Hope you don't plan on selling in the US because this behavior is going to get you sued into oblivion by the family of whoever ends up dead because the lights turned off abruptly on a vehicle with a faulty charging system.

This could be rephrased as:

"I do see a potential problem with lights turning off abruptly, for example if an accident occurs as a result it could open up the company to a lawsuit, even if it is the result of a faulty charging system."

I personally wouldn't agree (do normal battery makers get sued whenever a battery dies?) but it would no longer be gratuitously negative.

Re: Ohm (YC S15) is a smarter, lighter car battery that works with your existing car

#80

Post by tomkinstinch »

blueintegral wrote: post #62
tomkinstinch wrote: post #21

Earlier quoted context omitted.

Great product idea! One possible side market: have you looked at adapting the capacitor+battery combo for electric bicycles? It could be a great application: batteries for energy density, a capacitor as a buffer that can be filled quickly in a pinch (for charging while out and about, or from regenerative braking) and the capacitor could be discharged quickly for high-power acceleration. For short trips the capacitor…

Interesting! I had not thought of that, but it makes a lot of sense. What's the average electric bike battery capacity?

Around the same order of magnitude. Some are less than ten, some are more. It seems like most are aiming for about 10-15Ah these days, at 36V, 48V, or higher. Since capacity translates into range, the greater the better.
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