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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

#131

Post by atourgates »

sandworm101 wrote: post #27

(1) Those nasty things inside car batteries are easily recycled and in fact are recycled more often than not (like 95%+) (2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol) (3) Replacing an easily-recyclable product with a less-recyclable one is no step forwards. (4) XX addressed by OP comment,…

If you look at this purely from the standpoint of the benefit to a consumer, it doesn't seem like a great deal.

You gain:

* Auto-shutoff when your battery gets too low.

* Possibly some increased lifespan

* ~34lbs in weight reduction, which might deliver a small performance increase.

You lose:

* 78% of your battery capacity

* $20-$150 on the purchase price of the battery

Personally, I don't like the idea of paying more money for less battery capacity. If, however, Ohm came with a rock-solid 7-year replacement warranty, I might be able to get over that.

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

#132

Post by aidenn0 »

blueintegral wrote: post #50
sandworm101 wrote: post #27

(1) Those nasty things inside car batteries are easily recycled and in fact are recycled more often than not (like 95%+) (2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol) (3) Replacing an easily-recyclable product with a less-recyclable one is no step forwards. (4) XX addressed by OP comment,…

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'…

It will probably take a few years to get certified, but take a look at what goes for $600 as a flooded-cell battery in general aviation. The fact that you use LiFePO cells will probably help, as there is no way a LiPo would ever get approved.

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

#133

Post by blueintegral »

new2 wrote: post #117
blueintegral wrote: post #2

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

Hi Hunter, is there any regulation or certification process to make and sell car batteries ?

The DOT regulates your ability to physically ship batteries through the mail, but there's actually no formal stamp of approval that the DOT gives car batteries. They do have approval processes for other car parts, including electric car batteries though. We've been doing our own temperature and lifecycle testing so far, but we're still having 3rd party labs repeat all of that and also do destructive safety tests.

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

#134

Post by aidenn0 »

bri3d wrote: post #123
aidenn0 wrote: post #116

Earlier quoted context omitted.

Do LiFePO4 provide enough cranking amps for a sportbike?

Yes, absolutely. There are hundreds of LiFePO4 sportbike, ATV, and race car batteries on the market already (for example, http://www.batterystuff.com/powersports-batteries/LFX14L2-BS... ). I've also used one to run my Elise (2ZZ 1.8L 4-cylinder) for a few years now without issue. The three major issues I've heard about are are longevity, price, and reserve capacity. Cold weather is a bit of an issue, but strangely it…

Wow, 210 CCA from a LiFePO, I had no idea.

The supercaps provide a huge enhancement in longevity, since the maximum current draw from the battery is lower. This can even mean a difference in manufacturing for the battery in some cases, as there are design tradeoffs between peak current draw and lifetime.

It's also potentially lower weight and lower cost, since you won't need as large of a battery (EDLCs aren't cheap though, so there is a limit).

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

#135

Post by sliverstorm »

ams6110 wrote: post #120
smithkl42 wrote: post #37

My car has a significant design flaw(1), in that it allows children to turn on the backseat car lights and leave them on. I've had more dead batteries in the five years I've had sentient children than I've had in the 40 years prior. This is a great idea. (1) Perhaps the design flaw is in the children.

You have a Honda? The problem is I don't understand how the battery would shut down just lights and accessories without a) losing all your radio presets b) requiring entering the anti-theft code in the radio (risky because if you get it wrong you can brick your radio) c) still have power to know that you're trying to start the car. It seems to me this requires more than internal battery smarts but changes to the car'…

Yeah, it's really a problem best solved at the car level. Brownout detectors shut off all but the most important systems in the car, and then shut off everything when the battery is reaching critical levels to prevent damage.

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

#136

Post by nathanb »

thrownaway2424 wrote: post #106
sandworm101 wrote: post #27

(1) Those nasty things inside car batteries are easily recycled and in fact are recycled more often than not (like 95%+) (2) Car batteries do not last only 3-4 years as per the OP. Car batteries can last decades. There are many variables, but the car in my battery is far older than 4 years. (lol) (3) Replacing an easily-recyclable product with a less-recyclable one is no step forwards. (4) XX addressed by OP comment,…

You're right about the life. Who here has replaced a car battery after 3 years? My '89 Miata had the OEM battery (an AGM lead-acid battery), 25 years later.

Indeed. I wonder if Ohm works the same way, in that if you have an optimal driving pattern it will last you for 20 years. I suspect based on the Li-ion batteries in laptops and how poorly they last that the Ohm will have a much more predictable failure curve.

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

#137

Post by conjecTech »

itg wrote: post #124

Wouldn't this need to get DOT approval? Also looking at the replies from the founder, it looks like there hasn't been much actual safety testing done yet.

We've been asked this a few times, and from everything we've been able to find. DOT approval doesn't apply to starting batteries. There are two different things people generally refer to when they mention. 1) Transporting lithium batteries above a certain size requires an approval. For this one, the battery we use is below the levels they regulate. 2) there are also approvals you have to get for electric vehicle batteries which primarily stipulates a maximum amount of volume of electrolyte that it can spill in the case of it being destroyed in a crash, which doesn't apply to us at all. If we're wrong, and there is some regulation that does apply to us, we'd be more than happy to know about it. Please link me to it.

As far as testing, we've been driving on it ourselves for 5 months now. We have a cycle and temperature testing setup in our shop. We will do all of the testing we need to before we ship to anyone. Our earliest customers are likely to be the people in the world closest to us. We won't give you anything we wouldn't feel comfortable with them using.

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

#138

Post by devicenull »

shabble wrote: post #38
devicenull wrote: post #18

Earlier quoted context omitted.

> 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. How does that work? If the battery stops providing current to prevent itself from being fully drained, you're not going to have power to the car's compute…

One possibility: It will know when the internal batteries are running low (the internal charge/discharge monitor IC doing battery "gas gauge" measuring). It'll maintain a reserve of a few crank's worth of energy, and trigger shutdown before that's exhausted. It can also tell if the engine is running, because the alternator will be, and charging it. It can also monitor the active discharge current. If the battery is l…

Is the starter even going to crank before the computer is running? Old cars, sure I can see this working.

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

#139

Post by sliverstorm »

digitalneal wrote: post #40
msandford wrote: post #17

How does it handle a car that's iffy on starting? It's probably not hard to get something that'll crank a starter for a few seconds. But what happens if it needs to crank for 60 seconds over a 90 second window? I've got a 2006 Forester with a manual. I'll occasionally stall it backing out of a parking spot, so I'll have to start it again. For some reason it's much more difficult to start in between cold and warmed up…

Subaru ECU cold start logic is, well, questionable at best. As a side note, if your car is stalling that frequently, I would suggest adjusting the clutch engagement position. Sounds like its either very low or way too high.

You could just start the car in neutral, then the clutch engagement zone doesn't matter...

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

#140

Post by sliverstorm »

murbard2 wrote: post #96

So aside from what's been said, I can get this for $200 http://www.batteryspace.com/Powerizer-LiFePO4-Battery-12V-15... and it has 50% more storage than what is being advertised. What's the difference? The supercapacitors?

Yes, the caps. Classically the reason we use lead-acid in cars is its tremendous power density. Here they are combining LiPo (high energy density) with caps (high power density).

My truck battery pumps out 750CA for short bursts. That's about 12 horsepower. Lithium batteries can only accomplish that in large parallel banks.

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