Search this site:


June 23, 2005 12:05 AM

Broken: DC adapters, jumper cables

Dsc00744Seth Godin writes:

I studied engineering in college. I didn't, however, take Electrical Engineering. If I had, perhaps I would understand the following: Why do DC adapters cover more than one hole in a power strip? Worse, why are there so many different types--if I lose an adapter, I can't just replace it with another one from some device I've no longer got. I understand that engineers like the flexibility of using 6 volts or nine or even twelve when they prefer, but that's still only three types. Surely we don't need hundreds of shapes, sizes and jacks? It would actually cost LESS for every DC device to use the same transformer, with a small switch to set the appropriate voltage.

And while I'm on this rant, what's the deal with jumper cables? Jumper cables are medieval. For $30,000, why don't cars include an outlet you can hook a standard extension cord into? And an inverter that allows you to tap AC power if you need to plug something in--like your neighbor's dead battery?

Both cases of broken systems that persist because a plethora of suppliers refuse to momentarily inconvenience themselves while they standardize on a better solution.


broken yes, but in your case, not, because while you complain that it covers two holes, you provide a picture where its only taking up one.

Posted by: Dragon at June 23, 2005 03:10 AM

At least some manufactures of surge protectors have got the right idea and now include swivelling sockets at the end of the strip. That way you can put those offending huge block adapters at the end and swivel them out of the way of the nearby sockets. Can't remember the makers name off hand, probably Belkin though.

Posted by: Sit and Swivel at June 23, 2005 04:58 AM

"For $30,000, why don't cars include an outlet you can hook a standard extension cord into"

Because the "standard extension cord" would probably melt. How many extension cords do you know of are rated at two hundred amps plus?

That's the sort of current that starter motors drain. No domestic power supply can come close to delivering the instantaneous current required to start a car. mentions "hundreds of amps".

And why no inverter? A car battery can kick out hundreds of amps for thirty seconds, but running ten amps for a few hours will flatten it enough to not start a car! You don't want people treating cars as if they're mains sockets.

Posted by: Shannon at June 23, 2005 05:11 AM

I agree with the complaint about DC adaptors, but not about the jumper cables; comments above on that score are quite right.

But the thing that bugs me most about adaptors is that I have to take three with me when I travel on business -- one for my laptop, one for my cell phone and one for my PDA. OK, sure, I could get a smart phone and cut that down to two. And yes, I know the devices have different power needs. But would it really be that hard to design an adapter that puts out whatever amperage is required by the device you attach to it (up to some reasonable maximum, of course)? Or to design devices with universal power ports?

I'm not normally much of a conspiracy buff, but when you combine the adapter situation with the fact that no two batteries for portable devices are the same, it looks mighty suspicious to me.

Posted by: stoo at June 23, 2005 07:34 AM

Hooking up a standard extension cord from the house line may not work, but why can't every car have a retractable cord with a standard plug that will mate with the same standard plug from any other car. Why must one carry a set of Godzilla's nipple clamps everywhere, learn and remember what order to put them on and take them off, and Ghu help you if they accidentally touch?

Posted by: Anonymouse Coweird at June 23, 2005 07:45 AM

My power strip has 2 sides; one with close together outlets like in a normal power strip, and the other with 3 far-apart sockets for the offending AC adapters. The phone charger/adapter in the pic is nothing compared to my printer, scanner and speaker adapters, which are each as wide but a little shorter than my digital camera. The picture here could have done a beter job of explaining why, in fact, this is broken.

Posted by: Bob at June 23, 2005 08:12 AM

Most laptops now come with power inverters that have short cords to the "brick" and then a line to the laptop so that they don't cover up outlets. As far as why isn't there a universal one, I believe it has to do with not only the number of volts that need to be delivered (12, 24 etc.) but also the amount of current.

Posted by: Joshua Wood at June 23, 2005 08:29 AM

Do you REALLY want to know why auto manufacturers won't design a way to let you use an extension cord to jump start your car? Just watch the evening news and look at the number of electrical fires that burn down homes and apartment buildings and are started by "geniuses" using 99-cent extension cords and try to run high wattage hair dryers, DVD and HD-TV, etc. For that matter, take an inventory how many people actually use a real SURGE PROTECTOR for their PC ... not just a POWER STRIP with no surge protection?

Posted by: Ed at June 23, 2005 08:32 AM

The thing that's amazing to me about This is Broken is that almost everyone who comes and comments enjoys pointing out why things AREN'T really broken!

Of course, some things really aren't broken, but what puzzles me is why people would go to so much trouble to defend the status quo.

For example, I'm well aware that there's too much current to just plug in some lamp cord. But I also know that if they had just invented jumper cables, they sure wouldn't look like they look! In other words, just because jumper cables were the best we could do fifty years ago, why do we still have them now?

Posted by: seth godin at June 23, 2005 08:38 AM

The transformers are being changed. My current cell phone charger has a flat profile so that it doesn't cover up two outlets. This is a big improvement over my previous phone.

As for the jumper cables, others have already covered the problem of just using an extension cord. But other "solutions" to make jump starting a car more convenient basically add cost to the vehicle without any appreciable payback. Would built-in retractable jumper cables be a feature that would influence your car purchase? How often are you jump starting your car? It's not exactly a problem that cries out to be fixed.

Posted by: Carlos Gomez at June 23, 2005 08:43 AM

Huge power adapters are huge because of the large iron-core low-frequency transformers contained within them. These are called "linear" transformers. They are simpler in design than the smaller, newer switchmode transformers, which is why they are still prevalent. Your speakers have a huge brick because they have (relatively) huge power requirements.

And as far as jumper cables, everyone who has mentioned current is correct. Consider the electric arc welder. Some arc welders have potential differences of only 12 volts. It's the huge currents that do the job of melting metal. Want proof? Drop a spanner across your car battery terminals (don't forget to run). Twelve volts, huge current, red-hot wrench.

Posted by: Tired of Names at June 23, 2005 09:52 AM

Seth: You want to know why so many of us defend things as "not broken?" Because the word BROKEN is perhaps the most negative, invective, damning descriptive word you can give to a system. Jumper cables and brick-shaped DC convertors aren't broken, they are just extremely inconvienent. The word "broken" is patently inaccurate in these cases, and, what's worse, downright offensive to those of us who make this stuff in the first place.

That's not to say these products could not be improved upon considerably. "Anonymouse Coweird"'s suggestion of a jumper cable cord with a standard mating socket is a great one. Your point about backward compatibility of new designs with older cars would also have to be addressed. These are all great forms of *constructive criticism*, as they are all about explaining why an experience is unpleasant and how it can be improved.

Let's focus on the real positive opportunities! It doesn't seem helpful to angrily call a system broken when it clearly does achieve its intended goal.

Posted by: Robby Slaughter at June 23, 2005 10:03 AM


I think you might like something like this. You plug it into your car's cigarette lighter and wait about 10 minutes. It trickle charges your battery and you're good to go. No jumper cables, no looking for other cars etc.

So someone is building a better mousetrap, it's just some people are more comfortable with the status quo.

Oh, and the whole jumper cable thing is the reason why I park on top of hills, and just pop the clutch.

Posted by: Joshua Wood at June 23, 2005 10:04 AM

It is broken that how big power bricks are, I do not get why they couldn't make an adaptor that could supply different voltages and amperages at once, Like computer Power supplys are getting very small and powerful and thay on average provide at least 8 amps on each powerline, they usually have 3.3,5,12 volt lines.

Shannon: It is amazing what DC converters can do considering that a modern CPU can draw about 60 ampers but the powerdraw from the cord is only about 4-8 AMPs, So it is possible with a hefty transformer you could start the car with the mains.

Posted by: unknown at June 23, 2005 10:08 AM

Josh most cigarete ligthers only work when the key is in the ON psition so it would turn some systems like the computer and other stuff so all that would take power from the charger

Posted by: unknown at June 23, 2005 10:12 AM

"But would it really be that hard to design an adapter that puts out whatever amperage is required by the device you attach to it (up to some reasonable maximum, of course)?"

Ok, so the thing isn't providing multiple voltages simultaneously, but if you can stand to charge your stuff in series, rather than parallel, get yourself one of these - they have variable output, and interchangeable heads. I bought one several years ago... am I the only person here that knows these things exist (and have existed for several years)?

"I do not get why they couldn't make an adaptor that could supply different voltages and amperages at once"

Do you really want to travel with a power supply for things like a cell phone, a camera, and a palm pilot, that is the size of your computer's power supply? I somehow doubt it.

Posted by: at June 23, 2005 10:31 AM

I have a larger question. Why are there not sources of DC current in our homes and businesses? Most of the heat a computer creates is due to the transformer that takes AC from your home's plug and converts it to DC. The same is true for speakers, printers, cell phones, etc.

You would think someone would realize our need for DC as well as AC in the home (or how about the datacenter?).

Don't we have the technology to create a home current transformer (a box in our garage) that could provide DC power on demand.

By the way, if the transformer were designed right, it could also jumpstart a car.

Posted by: mudflap at June 23, 2005 10:35 AM

Easy solution to both problems: go Amish! No need to worry about power adapters or bulky jumper cables ever again...

Posted by: Amos at June 23, 2005 10:41 AM


Thomas Edison actually pushed for DC current in houses, he felt it was safer than AC current, but AC current is easier to generate and transmit.

>>From wikipedia

During the initial years of electricity distribution, Edison's DC was the standard for the United States, and Edison was not disposed to lose all his patent royalties. During the "War of Currents" era, Serbian immigrant Nikola Tesla and Edison became adversaries due to Edison's promotion of DC for electric power distribution over the more efficient alternating current (AC) advocated by Tesla, who patented AC in Graz, Austria. Edison (or, reportedly, one of his employees) employed the tactics of misusing Tesla's patents to construct the first electric chair for the state of New York to promote the idea that AC was deadly. Popular myth has it that Edison invented the electric chair, despite being against capital punishment, solely as a means of impressing the public that AC was more dangerous than DC. In fact, like most of the output of the Menlo Park operations, the chair was primarily invented by a few of his employees, in particular Harold P. Brown, while Edison supervised their operations. [1] (

Edison went on to carry out a campaign to discredit and discourage the use of AC. Edison presided personally over several electrocutions of animals, primarily stray cats and dogs, for the benefit of the press to prove that his system of DC was safer than that of AC. Edison's series of animal executions peaked with the electrocution of Topsy the Elephant.

Many of Edison's inventions using DC ultimately lost to AC devices proposed by others. AC distribution systems replaced DC, enormously extending the range and improving the safety and efficiency of power distribution.

Now that we've gone down this path, it's really impossible to go back, every electric device would need to be changed.

Posted by: Joshua Wood at June 23, 2005 11:15 AM

I think what he means that why not have AC and DC power in your house like a big huge 48 Volt tranformer in your garage that puts power to special DC plugs and the device that used DC would have a DC-DC converter to bring it to the voltage that it needed or just even a simple resister

Posted by: unknown at June 23, 2005 11:24 AM

There was a good article about all the adapters and rechargers we need, and being a slave to the electrical socket in the Washington Post:

"A Wireless World, Bound To Sockets: Consumers Crave Better Batteries for Gadgets"

I hope the link works for you.

Posted by: MGM at June 23, 2005 11:36 AM

This conversation brings to mind an article by Douglas Adams. The bits (only vaguely, admittedly) relevant to the discussion are near the bottom:

"I would now like to talk about cupboards. One particular cupboard. It's a cupboard in the corner of my study and I daren't go into it, because I know that if I go into it I will not emerge till the end of the afternoon and I will emerge from it a sad and embittered man who has done battle with a seething black serpentine monster and lost. The seething black serpentine monster is a three foot high pile of cables, and it both taunts me and haunts me. It taunts me because it knows that whatever cable it is that I want at any particular moment to connect one particular arcane device to another particular arcane device is not to be found anywhere in its tangled entrails, and it haunts me because I know it's right.

"I hate cables. They hate me too because they know that one day I will simply be able to go into that cupboard with a flame thrower and get rid of the lot of them. In the meantime they are determined to extract from me the last ounce of frustrated misery that they can. We do not need the bastards. We shouldn't need the bastards."

Posted by: anitsirK at June 23, 2005 12:22 PM

// just because jumper cables were the best we could do fifty years ago, why do we still have them now? //

Because they're good enough. I realise Seth's on a "they should be great enough" kick right now. But really: jumper cables are functional and cheap. They don't need to be perfect.

And as others have pointed out: they're very rarely needed. I've never needed a jump start, or been asked to provide a jump start, in 10 years of driving. Why ask every new car buyer to bear the cost of a slightly-improved system?

(More pragmatically, no auto manufacturer is going to be interested in promoting a feature, like a built-in jump-start socket, which suggests that the car is unreliable...)

Posted by: James Kew at June 23, 2005 12:36 PM


Posted by: . at June 23, 2005 01:32 PM

Or seatbelts and airbags that imply the car is unsafe. :D

Posted by: Joshua Wood at June 23, 2005 02:38 PM

Since Seth posted this, I wonder why the picture wasn't of his ipod charger.

/ I kid, I kid

Posted by: Joshua Wood at June 23, 2005 04:11 PM

radio shack carries universal dc adapters. I have seen the converter as a block beween the two plugs so one space used. as for jumper cables that is what AAA is for

Posted by: tylerg at June 23, 2005 04:20 PM

I would never use that generic converter as mentioned above to power all my electronic devices, if I was going to spring for one of those I would at least get it from RadioShack, not some anonymous online retailer. You want to know what's really annoying? My digital camera takes a 3.15 volt adapter, and it costs thirty dollars to buy from the manufacturer. I think I'm just gonna use a 3 volt...

Posted by: T-1000 at June 23, 2005 04:33 PM

T-1000: "if I was going to spring for one of those I would at least get it from RadioShack, not some anonymous online retailer"

hehe - "some anonymous online retailer"="The Source by CircuitCity"=Canadian Radio Shack. The Canadian RadioShack stores were sold to CircuitCity this spring, and RadioShack in the US sued for rights to the RadioShack brand in Canada, since CircuitCity and the company that owns RadioShack are competitors in the US... and the US company that owns RadioShack wanted to keep their options open for re-introducing the RadioShack brand to Canada. The store locations and all the products are the same, they just changed the names on the signs very recently. Check out for evidence to back up my claim.

Sorry for the derail.

Posted by: anitsirK at June 23, 2005 04:47 PM

I used to work at HP in presales info. If you needed a replacement power supply for your 1995-era laptop, or needed one for Europe, you had to pay $65. The power supply used the standard HP part number C####A. But if you were savvy, you could call the service phone number in Roseville, CA, and ask for the service part number, ####-####. That one cost about $38. And if you looked at the power supply itself, sho nuff, there were both part numbers right on it, one for $65, the other $27 cheaper.

Why do they make non-standard power supplies and charge you for them? BECAUSE THEY CAN.

Posted by: Boris the Spider at June 23, 2005 05:07 PM

In response to several people's questions and statements, I have a few things to say:

Booster Cables:

I am an electrical technologist (technician with a bit more theory) and I can tell you that "hundreds of amps) @ 12V = tens of amps at 120V. The «dead» battery can provide also part of the load. At my parents' house they have a charger/booster, which plugs into a normal 120V socket. The usual procedure is to charge the battery at long as you have time for, and then switch the charger to boost and start the car. A similar system could be installed in a car and designed to work automatically. (Instead of having to flip switches to change modes or turn it off)

My guess would be that car companies would rather put in systems supposed to stop the battery from draining too low (as some cars are equipped) than a system to boost the car. Also probably simply not enough people have asked for the system in their cars.

Finally it might be worth mentioning that "smart" booster cables exist. At the very least they are available at Canadian Tire (Yes I am Canadian)

Power packs:

Power packs can be made many ways, the problem is the smaller the size the more they cost or the less power they have. If you look around you could probably find a power supply that would do everything and not block multiple plug-ins, the question is how much are you willing to pay, and do you mind a big block in the middle of the cord.

As for having DC outlets in houses, the problem is that converting DC to DC means either turning it into AC and then back to DC or being limited to DC voltages the same or lower and creating even more heat than the transformer would have, because all a standard DC/DC converter does is turn extra volts into heat. Voltage transformers (the largest part of any relatively cheap power supply) only work on AC.

Posted by: Sean P at June 23, 2005 05:44 PM

By the way "smart" booster cables have some kind of interlock so that you dont have to worry about which cable goes where. The cables "decide" for you once they are connected. However the problem is they have the same clamps as normal booster cables and a control box as well, so they take up even more space in your trunk than the regular ones.

Posted by: Sean P at June 23, 2005 05:57 PM

One last comment for tonight; "universal" power supplies generally available (±5$ to around 35$) all have the same problem, the will provide diffrent voltages but the mA is fixed. What this means in pratical terms is :

If you plug in a device that requires too many mA then the power supply wil overheat, and may not provide enough power to allow the device to fonction properly.

On the other hand if you plug a device that requires to few mA into one of the cheaper ones, chances are the voltage will rise because it trying to provide more power than the device needs, and there is a risk of burning out your device.

Posted by: Sean P at June 23, 2005 06:20 PM

I am stupid!

Posted by: unknown at June 23, 2005 10:32 PM

I fixed my power strip problem with one of these. a 24 outlet power strip. It lays flat along the wall behind the desk, and has room for "Wall warts"

Posted by: Ted at June 24, 2005 12:53 AM

ya'll donta see whatsa goin ona, ima tomato!!!

seriously though, this is kinda broken but not really, i am suprised by one poster up there that in his 'extensive' driving career of 10 whole years he hasnt ever once had to get a jump or give one. must be the luckiest mofo ive ever heard of! i cant even begin to count how many times ive used my jumper cables, ive gone thru about 3 sets in the past 8 years and i really dont see a problem with em. i dont think a universal plug would work, simply because EVERY car has a + and a - plug/post on their battery, but what if that plug got broken, full of bugs, snow, ice, mud, etc...? now the plug ins on the other hand... that gets on my nerves... i hate looking behind my big screen cuz of all the wires back there, 1 each for the tv, dvd player, digital cable box, modem, router, video switch, cd player, gamecube, xbox, ps2, and our 2 laptops... thats not even alot of stuff compared to other people i know... then you have to have the huge plugs for damn near all of em, i had to spend some $ for a good surge protector that has more then 2 spaced apart plugins for those things...

Posted by: imwithstoopid at June 24, 2005 03:28 AM

My new phone charges off the USB lead - yes, it interfaces with my PC too. So I don't need to take my charger into the office, where I have another PC. Gosh. I'd like to see USB sockets on loads more devices, just for this useful charging and powering function. SO I could use for portable cd players etc. if they also were designed to the same power spec.

Posted by: duh at June 24, 2005 05:19 AM

Or seatbelts and airbags that imply the car is unsafe.

Posted by: Joshua Wood

I'm sure this statement was made in jest let me clarify that seatbelts and airbags are in the vehicle because they are required by law.

Its true that you can plug your car into your home outlet to charge the battery but it is very time consuming and you would have to schedule your battery drainage on the occassion when you are near an outlet. Jumper cables are on the otherhand quick.

As far as having the receptacle on your vehicle becoming impregnated with mud, bugs, etc.I'm certain they would be designed in a way similar to a fuel cap so that wouldn't be an issue.

Besides don't plug in cars already exist? electric cars although I've never seen one in person, so I don't know.

Posted by: kent at June 24, 2005 08:45 AM

"Besides don't plug in cars already exist? electric cars although I've never seen one in person, so I don't know."

Cars in notoriously cold climates regularly plug in to keep the battery charged and the engine warm enough to run. See:

Posted by: Boris the Spider at June 24, 2005 12:32 PM

WHat is worse is that many of these adapters do not have any information on them to tell which device they belong to. Lot of them have the name of some no name chinese company anbd voltage and polarity info. When you have 10 adapters mixed up it is very hard to figure out which goes with which device. Even if you get the polarity and voltage right there is no guarantee that the current rating will be ok

Posted by: Netninja at June 24, 2005 01:17 PM

These comments are terribly interesting. Zzz...

Posted by: Bob at June 24, 2005 06:04 PM

I'm suprised no one has mentioned these-

Power Strip Liberators-

They're basically 14" extension cords, costs $1.79 each. Plug the wall wart into one end, the other into the power strip. Not a skinny power supply, but clever, cheap and available.

Posted by: Mark Crummett at June 25, 2005 02:48 AM

boris the spider thanx for the info however; I was referring to an electric vehicle as opposed to the common fuel ran ones. I believe Honda has them and have been test marketed in CA where the epa standards are above average.

Posted by: Kent at June 25, 2005 06:03 AM

In response to mudflap, a lot of (most?) datacenters do have DC power. You have to request it, of course, and probably most people don't --- most computers run off of AC.

Posted by: Anthony at June 25, 2005 08:26 AM


The amperage that you refer to is at 12 volts, DC. It also refers to cold cranking amps (CCA), which is another story. Anyway, to keep it simple, let's say it takes 100 CCA to start a car. That's 12 volts x 100 Amps, which equals 1200 watts. Now, take a look at your hair dryer- bet it says something like 1200W. Does your hair dryer melt your wires? No- cause your not passing 100 amps at 12VDC through the wires. A much lower current at a higher AC voltage is being used.

Also, consider that you can buy welders that use a standard 120V outlet, draw 30 amps and deliver 130 amps at a lower voltage. My point is that the power needed to start a car is a function of voltage and current. It's not as simple as saying hundreds of amps are needed, because it's hundreds of amps from a 12 V battery. It would not be hundreds of amps from a 120 V AC source. Again, to keep it simple (it's late, I'm tired and a bit drunk)... ignore the AC... let's just use DC. Assume it takes 1200 W to start a car. That's 12VDC times 100 amps. Change the voltage to 120VDC and you only need 10 amps to equal 1200W (120V times 10 A = 1200 W) [power=voltage times current].

Could house AC really start a car? I dunno and don't have the desire to figure it out. However, add a bunch of big-a** capacitors, step down the voltage and I'm certain that I could plug my car into the wall to start it.

Mind you, big-a** capacitors are pricey and the added circuitry would increase the price as well. Given that I' been driving for 15 years and have yet to need to jump my car to get it running... why would I pay the extra cost to be able to plug my car into the wall to start it!??!

As far as the inverter... cars already have them. Keep in mind that power is the product of voltage and current. However, inverters aren't meant to be used while the engine is off. Car batteries are meant for a slow drain... they're meant to handle a sudden drain to start an engine and that's all. The charging system is what should be supplying the power for the inverters.

Posted by: me at June 26, 2005 01:54 AM

Hey Stoo...

I'm an electronics manufacturing engineer and one thing that seems to be constant is that companies keep the main unit cheap and rely on the consumables to profit from. So, you paid 50 bucks for that printer, but spend 30 for the cartridge. What are you going to buy most often? The cartridges of course.

As far as having a standard input voltage. Eh... there are quite a few variations on input voltages. Yes, some companies have a generic wall adaptor that supplies X volts DC at X amps and they design around that to keep THEIR cost down, BUT what does say, Sony gain from having a compatable wall adaptor with Kenwood?

Posted by: me at June 26, 2005 02:13 AM

Ok, so the original question.....

Power adapters are mainly a transformer and those transformers are designed to convert 120 VAC to xxx VAC. It's not a design flaw, they have to be a certain size in order to do the job. So, the design engineer picked the right transformer to convert 120VAC or 240 or whatever it is where you are to some other AC voltage before converting it to DC, if necesary. The design of the adaptor is based on it's output requirements. It's not based on the current design of a power strip. In a perfect world, yes, both output and location of use are considered. Really, the broken part is the power strips that aren't able to accomodate any plug.

Posted by: me at June 26, 2005 02:28 AM

To the Jumper Cables.

I'ma fireman, and we have a rule that requires fire trucks to have an externally accessible set of special jacks that will allow us to jump-start a fire truck without opening the engine compartment. These are NOT jumper cables in the classic alligator-clips on sterods sense, it's a simple connector with heavy cables.

Police cars and tow trucks use a similar setup, derived from the heavy-duty battery chargers used on Golf Carts and Forklifts. You can see these connectors here:

You can't avoid the need for a large starting current - which equates to a large current-carrying capacity - in a jumper cable application.

I'd suggest that while Seth is understandably annoyed by jumper cables, they are a product with a large installed base and the solution - high-power standardized connectors - costs more than than 4 sets of normal cables. There's no economic incentive - or design incentive for an improvement.

However, there may be a safety inducement. Batteries give off hydrogen gas. Every year, people have batteries explode when doing a jump start. Safer cables would avoid this problem.

Posted by: Martin at July 3, 2005 10:58 PM has an alternative to the powerstrip- it looks like an octopus. We were just talking about this annoyance the other day.

Posted by: Poor_Statue at August 29, 2005 09:31 PM

it is because the 'boxes' on them have to contain transformers to reduce the voltage from 240 to 12 or so

Posted by: eleven at September 26, 2005 08:46 AM

I have several commets to make. First of all, there are power adapters that chage multiple items. One init that comes to mind would me iJuice. As for the jumper cable issue, You can use a regular jumper cable to jumpstart your car as long as you use a charger that has the start feature. Drawing 100 amps at 12 volts would be like 10 amps at 12o volts. Most good car chargers can jump the car using AC voltage. Also, there are plugs available for cars that allow you to plug the cars into each other. They are usually on tow trucks and allow the driver to plug the jumper cables into the dead car and then plug the other end into a large, high amperage plug behind the grill. I was thinking of installing one of these plugs behind my car grill and attach the jumper cable side into a portable jumper battery . Instead, one could just install an auxilary battery with a solinoid that would connect the two batteries together in case of a failure. Thats what im going to do.

Posted by: TheDeepFryedBoot at February 7, 2006 02:11 AM

Why can't they put the adapter inside the device? All they'd have to do is move the internal wiring around a little and stick it in, or maybe make it just a little bit bigger.

Posted by: Eric at February 21, 2006 06:47 PM

Comments on this entry are closed

Previous Posts: