Ohm has worked up a drop-in replacement for car battery

Ohm has worked up a drop-in replacement for car battery

Ohm is a 6-pound drop-in replacement for your car battery. What's not to like about what it claims to deliver. It never needs jump-starting. Works on the coldest days (in temperatures as low as -40C). Lasts more than twice than lead-acid batteries, which go for three years. Here, you are looking at a 7-year average lifetime. No lead, no acid. When Ohm says it is a drop-in replacement they mean that it is installed in the same way.

The site says to "remove the positive and negative leads from your old battery, drop in Ohm, and reattach the lead to Ohm (red/positive lead first to prevent sparking)."

Also, Ohm is "smart" enough to prevent accidental draining if the driver forgets to turn off the lights. It can automatically turn itself off when critically low and switch back on when the driver starts the car.

How it works: There is a "burst of energy" for starting the engine which comes from a bank of supercapacitors. When the engine is not running, the supercapacitors are kept charged by a small array of batteries.

As for materials the company said its supercapacitors are mostly carbon. The batteries are LiFePO4 (.)

As for dimensions, Ohm's are 9.0"x6.8"x6.8", and will fit Group 35 batteries. "It will also fit in most cars above Group 35, but may require some extra fixturing, " according to the site.

When will you see Ohm in the marketplace? Not yet. Greg Kumparak, an editor at TechCrunch, reported that Ohm is in private beta testing and they plan to roll out a crowdfunding campaign in the next month or so. The website, meanwhile, said they plan to ship Ohm early to mid-2016.

Kumparak of TechCrunch addressed the question of price. He said he was told by the company that they aim for a price point of around $200. Kumparak said that would put 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."

Nonetheless, viewers might find the pricing amenable considering how long it lasts and some other benefits."Conventional contain dangerous acid and are responsible for over 24 million pounds of environmental lead contamination each year. Ohm has no lead, no acid, and is safe for the environment." Another promotion point being highlighted by Ohm is its light weight. "It's the easiest, most affordable way to instantly drop 30 pounds or more from your curb weight by switching from a -acid battery."


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More information: www.getohm.com/

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Aug 14, 2015
"There are V-8 BMW's that are changing SLI batteries with the oil" Doug why would they have to do that? 1 years seems to be a very short lifespan.

Aug 14, 2015
The site says to "remove the positive and negative leads from your old battery, drop in Ohm, and reattach the lead to Ohm (red/positive lead first to prevent sparking)."


But don't forget to wire in a second battery in parallel to the car's electric system before you remove the main battery, or else the onboard computers may trip and you get a christmas tree for a dashboard - and a trip to the dealership.

Some cars really don't like being completely powered off.

How it works: There is a "burst of energy" for starting the engine which comes from a bank of supercapacitors.


That means if the car doesn't crank to start almost immediately, the battery is going to die on you. There's not enough energy in the capacitors to keep cranking more than a couple seconds, so no second and third tries on a cold morning.

Aug 14, 2015
The other problem I see is that supercapacitors have high self-discharge, so the small lithium battery may not be able to keep them topped up for a very long time. If you leave the car at the airport, two weeks later is it still going to start?

The supercapacitors alone will empty over a weekend. Hence the battery.

It can automatically turn itself off when critically low and switch back on when the driver starts the car.


Same problem as before: dashboard christmas tree and non-starting car because the computers got cold booted. Not good.

All in all, nice trick, but I don't buy it.

Aug 14, 2015
I have just read up on BMW and their charging system that keeps track of battery health and requires that you "register a new battery with the car.I have designed and worked on a lot of electronic equipment in my life and this just looks like a ploy to make you go to the dealer for battery replacements. Somehow I am not surprised since the Germans always did want to take over the world.

Aug 14, 2015
But don't forget to wire in a second battery in parallel to the car's electric system before you remove the main battery

Now, I'm not a car person, but my electronics engineering background tells me that this may be extremely dangerous. If you put two batteries in parallel and they're at slightly different voltages, current will flow through them in a loop... potentially a VERY large current. This could cause the batteries to heat up and explode.

Surely this cannot be a recommended practice. Feel free to prove me wrong though.

Aug 14, 2015
Now, I'm not a car person, but my electronics engineering background tells me that this may be extremely dangerous.


Not very. Even when you connect an empty (11.5 V) battery with jump cables to another car's full battery (13.8 V), all you see is a little spark and maybe 5-6 amps of current. When the other car is already running and the alternator voltage is around 14.7 Volts, that's when you might see a bigger effect. You can get 20 amps through and if you have some puny household wire it may melt on your hands.

The internal resistance of typical a lead acid battery is surprisingly high, which is why they're so inefficient.

Car mechanics have small motorcycle type SLA batteries you plug into the cigarette lighter socket exactly for the purpose of changing the starter battery on cars that won't tolerate a cold reboot.


Aug 14, 2015
Lead acid batteries only last 3 yrs? Funny, mine last 6-7 yrs as long as I don't abuse them. This product sounds 'good on paper' bad in the real world. There are already Li-ion batteries on the market. Typically used for racing due to lightweight (see Summit Racing). All major battery distributors issue a refund for returning defunct batteries. No need to 'chuck 'em in the woods'. I suspect this is 'sponsored content'.
Disappointing in a forum such as this.

Aug 14, 2015
This comment has been removed by a moderator.

Aug 14, 2015
This comment has been removed by a moderator.

Aug 14, 2015
"Ohm is in private beta testing and they plan to roll out a crowdfunding campaign in the next month or so."

You see there is no reason to rob people with a gun anymore not when you have crowdfunding.

Aug 15, 2015
"According to company's info, Ohm's reserve capacity is 10 Amp hours. The typical car stereo draws about 15 amps, which means that you could run it on Ohm with the engine off for about 40 minutes."


Your radio does not consume ~180 W of power with an ordinary speaker system. the 4x45 W rating is just the maximum output power if you crank it to 11 with a suitable test track. Under normal conditions, it takes more like 18 Watts to play music at a reasonable volume, and even a 10 Ah battery goes for the whole afternoon.

But the headlights will draw about 20 amps and kill the battery in 30 minutes if you forget them on.


Aug 15, 2015
"low beam headlights together with tail light and electronics draw about 60 amps at night, air conditioner and defroster draw another thirty amps "


You're grossly over-estimating the power demands of a car. Two 55 Watt H4 should only draw between 7.5 - 9 Amps, not 20 as I remembered, and the taillights etc. are something like 4 Watts each. All told, probably not more than 300 Watts.

Your estimate puts the power demand of a car at nearly 1.4 kiloWatts, which is way too high.

The alternator has to power all the loads as well as charge the battery at the same time and be sufficiently over-rated so it doesn't overheat and break, and ordinary alternators are only rated for 60-80 Amps at full output. A large luxury saloon may have 120 Amps, and some older cars may be as small as 40 Amps.

Aug 15, 2015
We may not need starters on our cars for long.

Aug 15, 2015
We have been spoiled with electricity enabled accessories. Those crank turned motors had no such starter problems. I think there could also be crank and motor winded spring that would be used to start the ICE. Then the engine would normally wind it up for the next start, but it could also be hand winded with crank. Or we could have gasoline and air hybrid and that stored air could be used to start the ICE.

Aug 15, 2015
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Aug 16, 2015
"Normal lead battery keeps about 200 Ah."

I think it is closer to 70AH.

Aug 16, 2015
Normal lead battery keeps about 200 Ah.


60 Ah.

A lead acid 200 Ah battery would be huge and weigh over a 100 pounds. You might find one in a semi truck or in a boat, but not in an ordinary car. There's slight confusion because in the US car batteries are often rated by their cranking amps rather than their amp-hours.

It's still 25 A/12 V, which would drain the 10 Ah battery in twenty minutes.


The actual running voltage in a car is 14.4 volts, which is the upkeep voltage of a lead acid battery. The electronics are nominally 12 Volts, but they are actually designed for 14.4 V and so the current draw will drop when you turn the engine off - as you might notice because the headlights dim and the AC fan slows down.

300 Watts at 14.4 Volts is about 21 amps, and when the alternator is off it drops closer to 15 Amps. Then, when the battery empties the voltage and current drop further still, and that's why it takes somewhat longer to empty the battery.

Aug 16, 2015
We may not need starters on our cars for long.


Even the Tesla Model S has a 12 Volt "starter" battery.

Because it needs a secondary and redundant power system for the computers and controllers in case the main traction battery blows a fuse, and because standard car electronics don't come in 400 Volt versions.

It is literally just an ordinary 12 Volt lead-acid battery that's situated under the front hood, behind the glove compartment.

Aug 17, 2015
Have a pair of 24AHr SLA Lear jet APU starter batteries (in parallel) for a Holden Apollo 2.2L 4cyl (Rebadged Toyota Camry Wagon), these are the high quality so called 'pure lead' Hawker (narrow red) batteries same as certified for avionics, they were initially used in a high end UPS at the local Curtin University library server room & reached their end of life in ~2006.

They've been used in my car since & still start fine, though they're a bit down on CCA from new ~600A ea, last time I checked their parallel CCA was ~950

In summer, when daytime temps exceed 35 C & up to 44 C, they sit in water in the engine bay in a plastic battery box - sometimes in town I'll to drop into a local coffee shop & get a couple of take-away cups of ice & flood that into the battery box. Minor corrosion on the stainless steel terminals isnt a problem as its easy to brush off. In winter when it gets down to approx 20C the box is dry & they're fine.

Batteries both date coded 1996

Aug 17, 2015
last time I checked their parallel CCA was ~950


How did you check?

http://batteryuni...king_amp

There's no single standard as to how the CCA is measured, and some of the measuring methods are highly inaccurate depending on the state of charge of the battery.

SLA batteries are also a bit difficult, because high discharge/charge currents cause bubbles which get trapped in the gel electrolyte, which quickly reduces the amount of reactive surface area on the plates until the bubbles dissolve back into the electrolyte. That means the output current drops faster and again a brief pulse measurement for CCA over-estimates the output.


Aug 17, 2015
Eikka asked when I reported
last time I checked their parallel CCA was ~950
How did you check?
Service instrument from "Batteries Plus" in Perth, Western Australia, some 3 yrs ago, semi-portable micro-processor driven device to emulate starting an engine based upon expected rating as per the equivalent batteries as specified for that vehicle for that engine & expected load at 'cold', suffice to say the result was beyond the expectation by a fair margin with upward estimate - granted its not definitive as per lab instrument grade but, satisfactory is that it exceeded the 500A CCA spec at some 9.5V or so.

Eikka offered
http://batteryuniversity.com/learn/article/how_to_measure_cca_cold_cranking_amp
Nice link, moderated of course on actual starting ability for an engine with CR expectation of an engine within 5 yrs or 'normal' use

Given dynamic which occurs during load application & its affect upon internal resistance, I'd prefer practical...

continued

Aug 17, 2015
the result was beyond the expectation by a fair margin


I would say the result wasn't entirely truthful, or at least not standard. First, because SLA batteries as a category aren't rated to handle as much current for the simple property of being sealed - they'd burst from a buildup of hydrogen, and secondly because the shop that tested the batteries probably did not test them when actually Cold, which is what the first C in CCA means. It's not just the engine that is cold, the battery is cold as well, because it slows down chemical reactions.

A pair of 24 Ah SLA batteries probably won't give out 950 Amps when chilled to -18 C or even at 10 C, especially if the batteries originally came out of an UPS.

CCA and remaining battery capacity don't correlate very much.

Aug 17, 2015
Eikka being his usual contradictory self claimed
I would say the result wasn't entirely truthful, or at least not standard
Engineers don't talk like this, we talk about error margins & balance of probability, its obvious the word 'truthful' is not a useful term here, besides you just stated there was no standard now you say its not standard, Eikka read what you write.

Eikka added
First, because SLA batteries as a category aren't rated to handle as much current for the simple property of being sealed
You missed my point, they are same as avionic certified, they are not conventional SLA.

Eikka in lecture mode
- they'd burst from a buildup of hydrogen, and secondly because the shop that tested the batteries probably did not test them when actually Cold, which is what the first C in CCA means. It's not just the engine that is cold, the battery is cold as well, because it slows down chemical reactions
So what.

You missed the point Eikka they work !

Aug 17, 2015
Eikka imagines
A pair of 24 Ah SLA batteries probably won't give out 950 Amps when chilled to -18 C or even at 10 C, especially if the batteries originally came out of an UPS
Again you missed the point, just because they were 'used' in a UPS does not mean they were designed for a conventional UPS, note I did say "high end' likely well over-rated for that application

I did make it clear they are Hawker's, the certified version as I mentioned is used to start the APU for earlier jets. Although that IS likely beyond their spec re level of current it has proven most reliable

So Eikka you can argue all you like & lecture all you like about your idea it won't work but these batteries are circa 1996, I recovered them from a UPS, put them through few thermal cycles when charging to minimize sulphation & looked after them in summer, this has proved immensely effective

Its a case of applied engineering not lecturing why it won't work, its called real world experience !

Aug 17, 2015
Again you missed the point, just because they were 'used' in a UPS does not mean they were designed for a conventional UPS, note I did say "high end' likely well over-rated for that application


You miss the point: a battery designed for starting an engine has almost diametrically opposite properties and requirements as a battery designed for an UPS, so a high-end battery in the former application would not be "over-rated" for the latter. In fact it would probably be quite the opposite.

I don't doubt that they're very good batteries. I'm simply putting the measurement performed by the battery shop into question.

besides you just stated there was no standard


I said no single standard.

Engineers don't talk like this,


"Truthful" is a perfectly valid word in the english language. Why should not an engineer use it?

So what.


So that SLA batteries aren't designed for exceptionally high current output.


Aug 17, 2015
its called real world experience !


In my real world experience, an old and worn battery won't have much trouble starting an engine in warm climates until it's almost completely done and gone. It shows no obvious symptoms and generally works just fine.

It sounds implausible that a 24 Ah SLA battery would really have a CCA rating around 500 Amps because they use different electrolytes and structures which aren't suitable for very high current output. The fact that they're used in a Learjet isn't saying that the choice of battery is because of high output, but simply because they're sealed and leak-proof - which is more important in an airplane.

So I am simply expressing my wonder and doubt that this "Batteries Plus" shop did the measurement correctly or that their device was accurate, and whether your batteries are in such a good condition as you believe.

Aug 17, 2015
One has to remember that the starter motor even in a large V8 rarely draws more than 200 amps, hence why even weak batteries work years past their use-by date as long as they're warm and topped up with water.


Aug 19, 2015
Also, Mike, does the Holden Apollo come from the factory with SLA batteries? If not, then did you adjust the alternator/regulator in any way?

SLAs have lower upkeep voltages than normal flooded cells, and they'll be damaged by overcharging in a car circuit designed for regular starter batteries. Usually this isn't a problem since people drive such short distances that the battery barely tops up, but on a longer trip you may be boiling the battery.

Aug 27, 2015
I changed the lead acid battery in my vehicle 6 years ago, the old one had lasted 9 years. I don't know who manufactures their 3 year battery, but I suggest a different source. And as for the millions of pounds of environmental lead contamination, well that is one of the main reasons for recycling. This thing is nifty, but not that practical.

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