A handy little Jump Starter?

hardrockjock · Post by **hardrockjock** » Mon Apr 28, 2014 4:40 pm

http://www.pistonheads.com/news/default ... ryId=29881

flyingscot68 · Post by **flyingscot68** » Mon Apr 28, 2014 4:59 pm

Sounds too good to be true.

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tut · Post by **tut** » Mon Apr 28, 2014 6:03 pm

Tis not exactly rocket science to check whether it works or not.

Partly discharged car battery that will not start, attach the gizmo, if it starts then half way there. Then try it on a flat battery that barely lights up the instrument lights, if it still works then you have a winner.

tut

David · Post by **David** » Mon Apr 28, 2014 6:23 pm

I think it is developed from this idea https://www.youtube.com/watch?v=z3x_kYq3mHM - basicaly high capacity, high current capacitors.

tenkfeet · Post by **tenkfeet** » Mon Apr 28, 2014 7:55 pm

Know of a lithium ion battery from an e Cigarette that recently exploded while charging from a laptop. It fired across a room embedded in a wall and set fire to an office. Fire brigade said it got to 1000 degrees C.

This bad boy would make a mess if it decided to destroy itself like they have a habit of doing at present.

mxvx · Post by **mxvx** » Mon Apr 28, 2014 7:58 pm

tenkfeet wrote:Know of a lithium ion battery from an e Cigarette that recently exploded while charging from a laptop. It fired across a room embedded in a wall and set fire to an office. Fire brigade said it got to 1000 degrees C.

This bad boy would make a mess if it decided to destroy itself like they have a habit of doing at present.

robin · Post by **robin** » Mon Apr 28, 2014 8:52 pm

According to PH, it is a Lithium (Polymer) Ion battery, not super-caps; in fact super caps come in two flavours and neither is a replacement for even a small lead acid battery; one form of super cap is designed to produce a very low output current for a long time but collapses in the face of a high current load; the other is designed to supplement the car battery/alternator to provide for the instantaneous current requirements of big car hifi systems. As a replacement for a car battery, it won't work ... I didn't watch the Youtube, but I assume it failed!

For RC model enthusiasts there are batteries that can discharge at 20C where C is the nominal capacity of the battery. So 6Ah battery would give 120A peak. I guess they may have some electrode technology that allows even higher discharge currents - the motor industry must be developing batteries like that. What makes me doubt that these guys have access to that technology is their product background, which is not really high tech batteries.

Assuming the battery can hold up at all, then 6Ah might just last long enough to crank your car, but it better be a good starter!!

I was actually thinking about getting a tiny petrol motor and alternator to make a portable generator to recharge your battery (slowly), or if it could produce about 30A (about 360W, or half a horsepower) then it could allow you to run the engine when your alternator fails when you're in Europe and you don't want to go home on the AA trailer

, though you would have to hang the wee exhaust out the window or die of carbon monoxide poisoning

Re: the exploding LiPo from the eCig - a lot of these products are not properly safety tested - a client asked us to look into helping them design one, and they had bought a number of competing products so that they could study the innards - none of the batteries had a secondary isolation circuit - a mandatory feature for getting CE. Yet they are all CE marked. You've been warned - don't leave them where catching fire might lead to a H&S risk (ironic for cigarettes, really!). it is a market that needs regulating for many reasons!

Cheers,
Robin

RDH · Post by **RDH** » Tue Apr 29, 2014 5:15 pm

robin wrote:

Re: the exploding LiPo from the eCig - a lot of these products are not properly safety tested - a client asked us to look into helping them design one, and they had bought a number of competing products so that they could study the innards - none of the batteries had a secondary isolation circuit - a mandatory feature for getting CE. Yet they are all CE marked. You've been warned - don't leave them where catching fire might lead to a H&S risk (ironic for cigarettes, really!). it is a market that needs regulating for many reasons!

Cheers,
Robin

I'm currently working in our Shanghai office and had a meeting with a local manufacturing organisation's general manager, if you want the CE mark, it can be added for next to no cost at all. Doesn't mean you meet the CE standards, but welcome to China!

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robin · Post by **robin** » Wed Apr 30, 2014 8:47 am

That's is not so mad as it sounds. The responsibility for meeting CE requirements belongs to the first importer into the European market. Assuming that importer is confident that the product meets the requirements (for example, they've done some testing, or have deduced that the product requires no testing) then it would be reasonable for the importer to ask the manufacturer to add the CE logo - otherwise they would have to unbox each item, apply the sticker and then rebox.

What is more worrying is that people ask for the CE label without doing any testing. I have seen plenty of dangerous electrical products for sale with CE marks on them - I recently unscrewed a walky-talky charging base station that was clearly a toy so would be used by kids. It had the CE mark and the double-square double-isolation mark (which is an electrical safety label meaning that the product does not require earthing). Inside the mains cable was supported by just the solder joints and the bare electrical contacts were within 10mm of the spring contacts that you can touch from the outside of the unit. I am pretty sure that if you dropped 100 of them, 1 would end up with a live spring contact waiting for some inquisitive child's fingers ... and even if that wasn't true, the double-isolation symbol was wholly inappropriate given there was barely single isolation ...

Unfortunately we don't have any effective regulator to stamp out this sort of rubbish ... see bs1363.org.uk for a small sample of the bewildering array of unsafe product for sale online and in your local foneshop.

My advice is never buy anything with a mains plug on it from foneshop, eBay, Amazon, etc., unless you can be sure of the original manufacturer (e.g. Toshiba are bound to make stuff that is safe; so it's OK to buy a Toshiba telly from Amazon). If you are tempted to buy some cheaper electrical products off eBay you need to decide for yourself whether the product you receive is safe; under no circumstances should you assume that CE mark implies compliance with the relevant safety standards. If in doubt, ask for the DoC (and don't hold your breath for an answer).

Cheers,
Robin

jason · Post by **jason** » Wed Apr 30, 2014 9:31 am

^ that's a sobering read about the charging station, Robin.

Wrongly, I had always naively trusted CE marks were the result of independent product testing/approval.

robin · Post by **robin** » Wed Apr 30, 2014 2:06 pm

No, it is totally up to the manufacturer or importer to asses what standards are applicable, test to those standards and apply the appropriate labelling. Trading standards may confiscate product that does not comply (which is an issue for the retailer) but I have never heard of anyone being prosecuted for applying labels that were not appropriate. It's a real shame - for Amazon it would be so simple to hold them accountable - where are they going to run to? Most of the breaches are totally unnecessary - many products would pass if tested, or pass with minor modifications; the walkie talkie charger could easily have been made safe at negligible cost.

I guess that's the problem with a heavily regulated system - you rely on people playing by the rules because you (the state) don't have the bandwidth or resources to enforce all of the rules you've made! Anyone willing to break them can do so with impunity, most of the time.

Cheers,
Robin

Post by **pete** » Wed Apr 30, 2014 3:42 pm

I bought a HDD external power supply (lets you run an internal HDD via USB and mains power).

Surprisingly I actually got a recall notice fromt eh eBay vendor saying some of them caught fire and could I retunr it for a refund. As it was less than a fiver I ignored it, and as I couldn't see another one on eBay kept using it. (I hardly ever used it, it was just to fiddle with stuff when it was nearly broken anyway.)

Then one day it caught fire. Properly - pop, bang, flames and burning plastic. Would definitely have burned the house down had I not heroically saved the day.

robin · Post by **robin** » Wed Apr 30, 2014 7:37 pm

I wonder whether your house insurance would then have taken the opportunity to not pay out, had they known you were fully cognisant of the risk and yet chose to ignore it

Post by **campbell** » Thu May 01, 2014 12:09 am

They already weighted his premium in anticipation. It's Pete, after all!

Post by **pete** » Thu May 01, 2014 1:27 am

My wife insists that I am never any further from 3 yards from a fire extinguisher, partly because as Campbell guessed I am a little accident prone and partly since she learned I'd followed Robin's advice and canceled all the insurance.

Scottish Elises