ebent
10 kW
Is there risk of electricution? How much voltage and or amps will hurt you and how much to kill you? Is there any history of ebikers seriously harmed by our lithium packs? Thanks.
How much danger is there for e batteries?
- Thread starter ebent
- Start date
RC Extreme Power
10 mW
- Joined
- Aug 18, 2012
- Messages
- 27
ebent said:
Never heard of someone seriously hurt with Lipo's or other batteries but have heard of a few houses and cars burned from the not being handle properly.
Batteries are DC voltage and will not hurt you like your AC house current will.
Milton
arkmundi
10 MW
I've held the postive & negative terminals of my 36V A123 AMP pack and feel a very slight tingle. There's not enough voltage there to turn the human body into a conductor, so no risk at all. If the terminals are put in short-circuit, however, sparks will fly. If the short circuit material can flame at high temperature, like aluminium, those sparks may be particulate, meaning they could conceivably fly into your eye and do some physical damage. Don't do that and you're OK.ebent said:
FYI, LiFePO4 batteries are considered the "safest" of the Li-ion class. See Agnisium's video of him attempting to destroy a A123 AMP cell to the point that'd it would flame, without success. I don't believe there is a heat or flame risk with my battery pack. Contrary to other precautions, I charge my pack inside and without a container. The biggest risk I believe I face is emotional scaring should my pack be stollen. Seems I've fallen in love with my battery.
A loss would cause me grief. 
John in CR
100 TW
It doesn't take much current at all across the heart to interrupt your heartbeat. We have pretty high resistance though so the risk goes up with voltage. To kill you requires more odd circumstances like grabbing the positive in one hand and negative in the other with enough sweat on your skin for a good contact. Burns and shock are the common injuries, and yes it is dangerous, so you do need to careful and deliberate.
Probably the most common accident is making a reversed polarity connection. It only lasts and instant because it literally vaporizes the metal near that connection, and skin in the vicinity typically gets burned. You'll get comfortable with it in time, just don't get complacent, because our batteries can release incredible energy in a flash, a blinding flash.
Probably the most common accident is making a reversed polarity connection. It only lasts and instant because it literally vaporizes the metal near that connection, and skin in the vicinity typically gets burned. You'll get comfortable with it in time, just don't get complacent, because our batteries can release incredible energy in a flash, a blinding flash.
ebent
10 kW
I've experienced the kff syndrome. Did not lose the battery or get burned.
The way I read these 3 responses is RC extreme and arkmundi feel that dc current can't hurt but John feels it needs to be considered. A majority but not unanamous.
John, can you put a number on the voltage that makes a difference.
What if there was a bare of wire importance with the throttle wide open that was touched?
Could you electrify standing water that was dangerous with the right circumstances?
These are unanswerable questions for me as knowledge of electricty is not my strong subject. I'm not overly concerned of a mishap, but I feel slightly vulnerable on these issues due to not knowing. Once I'm certain, I'm sure it will be easy to manage.
Thanks.
The way I read these 3 responses is RC extreme and arkmundi feel that dc current can't hurt but John feels it needs to be considered. A majority but not unanamous.
John, can you put a number on the voltage that makes a difference.
What if there was a bare of wire importance with the throttle wide open that was touched?
Could you electrify standing water that was dangerous with the right circumstances?
These are unanswerable questions for me as knowledge of electricty is not my strong subject. I'm not overly concerned of a mishap, but I feel slightly vulnerable on these issues due to not knowing. Once I'm certain, I'm sure it will be easy to manage.
Thanks.
Drunkskunk
100 GW
There is no general diffrence in safety between AC and DC. Both can kill. In specific instances, either can be deadlier, but there is no "Safe" electricity. It only takes 50mA across the heart to kill, and that can be provided by a watch battery. But Skin offers resistance and a path for the electricity to flow without passing through the heart. Thats why stun guns are generaly safe, that work at hundreds of thousands of volts.
Generaly, though, 48 volts and less is considered safe. Higher voltages have higher risk, but you're not likely to drop dead from Ebike voltages. 48 volts is the chosen voltage of phone companies to run phone lines at for several reasons, one being it's safe for people to work on the live lines without risk of injury. But you can generaly feel 48 volts shocking you. its unpleasant but not harmfull.
touching a single wire isn't dangerous by it's self. To be shocked, you must complete a circuit. The electricity from a battery can only flow back to it's self, and will flow through the path of least resistance back to it's self. If you touch 1 wire only and the battery is not grounded, you can't be shocked because the electricity can not flow through you back to the other terminal
Electrifying standing water with an Ebike battery would be less dangerous than touching bare wires because water is not a great conductor of electricity.
Generaly, though, 48 volts and less is considered safe. Higher voltages have higher risk, but you're not likely to drop dead from Ebike voltages. 48 volts is the chosen voltage of phone companies to run phone lines at for several reasons, one being it's safe for people to work on the live lines without risk of injury. But you can generaly feel 48 volts shocking you. its unpleasant but not harmfull.
touching a single wire isn't dangerous by it's self. To be shocked, you must complete a circuit. The electricity from a battery can only flow back to it's self, and will flow through the path of least resistance back to it's self. If you touch 1 wire only and the battery is not grounded, you can't be shocked because the electricity can not flow through you back to the other terminal
Electrifying standing water with an Ebike battery would be less dangerous than touching bare wires because water is not a great conductor of electricity.
e-biker
100 W
It is no more dangerous than a firechacker I have never heard of anyone getting killed from or serious injury from dc voltage and I run 100 volt and above packs and touch both pos and neg with my hands at the same time but never touch them together stright wire to wire thats where you will get a burn, relax be on your game when dealing with d/c batteries the damage to the batteries and bms will be worse than to you.
dogman dan
1 PW
I see the main danger as being what happens when you short circuit the wiring. I dead shorted an alternator wire to the hot exhaust on a truck once, when a wire retainer failed. It was quite amazing how much 12v did to every wire in the truck. Many wires melted completely, lots of heat. A passing dude with a fire extiguisher saved the whole truck from going up.
So that's the reason eary ebikes went only to 24v, then 36. Less volts, smaller sparks when shit happens, less risk of the whole thing burning the house down.
Once you get into even higher voltage, a dead short on 72v will weld real good. I'd treat it as just as hazardous as 110v ac. No grabbing bare wires, period.
So that's the reason eary ebikes went only to 24v, then 36. Less volts, smaller sparks when shit happens, less risk of the whole thing burning the house down.
Once you get into even higher voltage, a dead short on 72v will weld real good. I'd treat it as just as hazardous as 110v ac. No grabbing bare wires, period.
That entirely depends on the voltage. I dare you to go stick your tongue on JonesCG's new pack.RC Extreme Power said:
spudboy62
1 mW
48V DC or less is low enough that it won't push much current through your body if you touch bare wires, meaning that you won't get electrocuted at these low voltages.
High current hard or soft shorts can cause burns and a lot of destruction. You can burn your skin with a 1.2V AA NiCd cell with the right load on it. For example, a cordless soldering iron uses a few NiCd C cells in series. The best way to protect against high current burns is to fuse / circuit breaker the pack as close as possible to the cells; don't run un-fused power around the bike.
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High current hard or soft shorts can cause burns and a lot of destruction. You can burn your skin with a 1.2V AA NiCd cell with the right load on it. For example, a cordless soldering iron uses a few NiCd C cells in series. The best way to protect against high current burns is to fuse / circuit breaker the pack as close as possible to the cells; don't run un-fused power around the bike.
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High voltage DC has the unfortunate effect of causing sustained muscular contraction. So if you grab a conductor you'll likely not be able to let go. Whereas with AC, the pulsing current should throw you off.
Still, your clutching at straws if your survival comes down to a factor like that. Much better to be more careful in the first place
IIRC wet skin has a resistance of about 100 ohms, so a 100V battery would put about an amp through you. That's got to hurt and burn if nothing else...
Still, your clutching at straws if your survival comes down to a factor like that. Much better to be more careful in the first place
IIRC wet skin has a resistance of about 100 ohms, so a 100V battery would put about an amp through you. That's got to hurt and burn if nothing else...
ddk
100 kW
- Joined
- Nov 4, 2011
- Messages
- 1,903
one time...
in band camp...
-no-strike that-
one time at work I strung enough 'used' 9V batteries together for about 150V.
I dared somebody-who-shall-forever-remain-nameless to 'test' it with his tongue. (supposedly another engineer- or so he claimed)
I tried to stop the idiot from doing so but I was too late as he was thrown against the wall.
No serious harm done but a lesson for somebody- (me)
in band camp...
-no-strike that-
one time at work I strung enough 'used' 9V batteries together for about 150V.
I dared somebody-who-shall-forever-remain-nameless to 'test' it with his tongue. (supposedly another engineer- or so he claimed)
I tried to stop the idiot from doing so but I was too late as he was thrown against the wall.
No serious harm done but a lesson for somebody- (me)
Samd
10 MW
Come join the research thread - tested on animals.
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=43563
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=43563
Ykick
1 GW
Working with tube amps I learned a lot of respect for 300-500VDC. One hand in your pocket is a good technique to avoid passing DC through your heart.
50VDC's sorta docile but DC bites and won't let go - healthy dose of respect goes a long way.
50VDC's sorta docile but DC bites and won't let go - healthy dose of respect goes a long way.
Sunder
10 MW
I read an electrician's risk assessment document once that had table similar to this:
Voltage - Risk
0-50v - Risk, minimal - may cause fires from sparks and short circuits.
50-250v - Risk of electric shock
250v+ - Risk of electrical arcing.
There was a lot more detail in how to manage the risk, but I recall the main point being anyone can work on 0-50v, a licensed electrician can work on 50-250v, but an electrician with additional specialist training is required to work on 250v+ systems, including three phase, and transmission level electricity.
Voltage - Risk
0-50v - Risk, minimal - may cause fires from sparks and short circuits.
50-250v - Risk of electric shock
250v+ - Risk of electrical arcing.
There was a lot more detail in how to manage the risk, but I recall the main point being anyone can work on 0-50v, a licensed electrician can work on 50-250v, but an electrician with additional specialist training is required to work on 250v+ systems, including three phase, and transmission level electricity.
ddk
100 kW
- Joined
- Nov 4, 2011
- Messages
- 1,903
the worst shock I received that started my heart to fibrillate for several hours afterward was on a hot, sunny day where I was working an outdoor concert. There was 65ma and 90V (60Hz ac) difference between the lighting tower and my sound mixer as i balanced myself with one sweaty hand on the mixing desk and one sweaty hand on the tower = one quick trip to the hospital
i.e it doesn't take much under the wrong circumstances
you furinors haz usa beat because you don't usually use 60Hz as a frequency standard
note: but it's really difficult to get hurt with the voltages present in an e-bike. You have to try extra hard :lol:
i.e it doesn't take much under the wrong circumstances
you furinors haz usa beat because you don't usually use 60Hz as a frequency standard
note: but it's really difficult to get hurt with the voltages present in an e-bike. You have to try extra hard :lol:
Lessss
1 MW
more elephants have been killed by ac than dc, thanks to a dickhead named Edison.
Just to throw in another thought:
AC is apparently more likely to cause heart fibrillation, whereas DC will stop the heart. A stopped heart is much more likely to resume normal rhythm on its after the shock is over. The cure for a fibrillating heart of course being a nice belt of DC from a defibrillator :lol:
AC is apparently more likely to cause heart fibrillation, whereas DC will stop the heart. A stopped heart is much more likely to resume normal rhythm on its after the shock is over. The cure for a fibrillating heart of course being a nice belt of DC from a defibrillator :lol:
Jason27
10 kW
Batteries are only a safe as the person who is wiring them. Take the proper safety precautions and pay attention you should be ok.
friendly1uk
1 MW
UK
The big yellow site transformers offer 110vac from a well isolated secondary. The earth (or cpc (circuit protective conductor)) is a center tap off this same winding. Putting the earth at 55v from both phase and neutral ends. This makes the maximum shock voltage 55vac unless very unlucky. As yet, nobody has died, but some made a death gasp when there favorite power tool hit the ground.
Some deaths do occur at 50vac, but mostly through complications. Like falling off a ladder, or an already weak heart. It appears many countries have a cut off point of 50vac woven in to there regulations. 50vac is the rms value, It's peak will be 82v. That's 82v trying to work your muscles at whatever frequency. That's what mashes everything up, the rippling effect. A really smooth source of dc such as our batteries won't do so much harm. 120vdc is comparable to 50vac(as that is 82v at high frequency) in all the regs I have seen.
5 second, 50v, 50ma is the death equation. I give you any two of them through negligence, and it's manslaughter if you died. It's related to currant through the heart when you form a circuit from hand to hand. Most shocks are fine as the currants entry and exit points don't include the route through the heart. Shortest route and all that. If you do take the live in one hand and the neutral in the other then your in trouble as the shortest route is through your chest. Around 50ma your heart has about 5 seconds, while over 50ma your chances decrease rapidly.
Skin resistance changes all this lots. Wet hands and dry body is the worst combination. You will carry the currant through your wet skin like an invitation, and your dry body limits any possible surface currants that might of saved you.
We have exposure problems between controller and motor, and on the motor ground if it's lost. Our dc does not remain dc for long. It might not get inverted like ac, but it's switched at a fairly high frequency, it's certainly not ripple free battery power. A loose wheel is a shock hazard if the controller is still in cruise and you fell off. Anyone picking up the frame and wheel could be killed. Freak condition, yes, but if you can't see the possibilities, stick to low voltage.
e-biker, are you dead yet? you won't die with both in one dry hand, you might not even notice with thick dry manly skin. Even wet it might just tighten your grip a bit. Do that hand to hand though and it will tighten your heart. The nervous system doesn't seem to like this external interference, and normal heart function may not be resumed.
Quick google shows the latest electric chair victims and there resistance. From 150 to 230 ohms. I believe wet (or moisturised)hands holding a wire in each could be fatal using some of the larger packs I see used on ES
The wiring regulations revolve around this kind of thing. It's 20 years since I got up to speed with the latest edition though. I don't even have it.
The big yellow site transformers offer 110vac from a well isolated secondary. The earth (or cpc (circuit protective conductor)) is a center tap off this same winding. Putting the earth at 55v from both phase and neutral ends. This makes the maximum shock voltage 55vac unless very unlucky. As yet, nobody has died, but some made a death gasp when there favorite power tool hit the ground.
Some deaths do occur at 50vac, but mostly through complications. Like falling off a ladder, or an already weak heart. It appears many countries have a cut off point of 50vac woven in to there regulations. 50vac is the rms value, It's peak will be 82v. That's 82v trying to work your muscles at whatever frequency. That's what mashes everything up, the rippling effect. A really smooth source of dc such as our batteries won't do so much harm. 120vdc is comparable to 50vac(as that is 82v at high frequency) in all the regs I have seen.
5 second, 50v, 50ma is the death equation. I give you any two of them through negligence, and it's manslaughter if you died. It's related to currant through the heart when you form a circuit from hand to hand. Most shocks are fine as the currants entry and exit points don't include the route through the heart. Shortest route and all that. If you do take the live in one hand and the neutral in the other then your in trouble as the shortest route is through your chest. Around 50ma your heart has about 5 seconds, while over 50ma your chances decrease rapidly.
Skin resistance changes all this lots. Wet hands and dry body is the worst combination. You will carry the currant through your wet skin like an invitation, and your dry body limits any possible surface currants that might of saved you.
We have exposure problems between controller and motor, and on the motor ground if it's lost. Our dc does not remain dc for long. It might not get inverted like ac, but it's switched at a fairly high frequency, it's certainly not ripple free battery power. A loose wheel is a shock hazard if the controller is still in cruise and you fell off. Anyone picking up the frame and wheel could be killed. Freak condition, yes, but if you can't see the possibilities, stick to low voltage.
e-biker, are you dead yet? you won't die with both in one dry hand, you might not even notice with thick dry manly skin. Even wet it might just tighten your grip a bit. Do that hand to hand though and it will tighten your heart. The nervous system doesn't seem to like this external interference, and normal heart function may not be resumed.
Quick google shows the latest electric chair victims and there resistance. From 150 to 230 ohms. I believe wet (or moisturised)hands holding a wire in each could be fatal using some of the larger packs I see used on ES
The wiring regulations revolve around this kind of thing. It's 20 years since I got up to speed with the latest edition though. I don't even have it.
I'm trying to research here how likely will I get a shock from 72 volts from touching a exposed positive wire in one hand and and an exposed negative wire in the other hand?
The reason I ask this is when I am connecting my battery to the controller, the connectors are so hard to pull apart that I pulled back the insulation on the negative wires.
I have not for some reason pulled back any insulation from the positive wires. The risk is always there that the insulation will pull back a bit from the positive wires. This may allow me while plugging in my battery to touch a positive wire in one hand and a negative wire in the other hand.
Will this kind of touching be enough to shock me through my body and stop my heart?
I worry about this every time I touch those wires, as I have three separate connectors to plug in when connecting to my controller, also when connecting them to the charger.
Well, I guess when plugging them into the charger they would only be 6s lipo or 24 volts per wire.
The reason I ask this is when I am connecting my battery to the controller, the connectors are so hard to pull apart that I pulled back the insulation on the negative wires.
I have not for some reason pulled back any insulation from the positive wires. The risk is always there that the insulation will pull back a bit from the positive wires. This may allow me while plugging in my battery to touch a positive wire in one hand and a negative wire in the other hand.
Will this kind of touching be enough to shock me through my body and stop my heart?
I worry about this every time I touch those wires, as I have three separate connectors to plug in when connecting to my controller, also when connecting them to the charger.
Well, I guess when plugging them into the charger they would only be 6s lipo or 24 volts per wire.
999zip999
100 TW
I sat a 36v 20ah of A123 on the floor of a hardware store when the leads touch the floor tile it popped and sparked thru the floor tile. Like a gun fire. Conductive floor tile ? Yes the leads did not touch each other.
I had to Edit.
I had to Edit.
Well, at that voltage you'll definitely feel it, and it'll probably hurt, but I don't know if it would stop your heart--that will probably depend on conditions that allow current flow, so that if hte current is high enough, and in the right path so it goes across/thru your heart.
I've been zapped by 59VDC between my inner thigh and my hands, when I had a wiring problem on an older version of CrazyBike2, and it hurt but it didn't kill me. No idea of what current was flowing, though. Was not direct skin contact, as my thigh was in sweaty pants, my hands were sweaty on the rubber grips of the bars, but wetness across the grips allowed flow from the bars' metal to my hands.
I've been zapped by 59VDC between my inner thigh and my hands, when I had a wiring problem on an older version of CrazyBike2, and it hurt but it didn't kill me. No idea of what current was flowing, though. Was not direct skin contact, as my thigh was in sweaty pants, my hands were sweaty on the rubber grips of the bars, but wetness across the grips allowed flow from the bars' metal to my hands.
TotalConfusion
100 W
Well i havnt been hit with DC at all apart from a car coil, lol.
I did end my caree as an electrician when i was hooking up a 3 phase motor and my idiot boss flicked the breaker on after taking the do not remove tag off and hit me with 415 and i got hooked up for a few seconds with potentially 415V and cables that could draw over 150 Amps and i went down and cant remember a thing until the next day in Hospital.
The doctors told me it all has to do with your heart beat and when the heart is fully contracted that is when you are at most risk of it not starting back up because of the rythm of your heart cant expand due to the current in your body so your heart stops beating. You have to be very unlucky with the timing for this too happen otherwise alot more of us would not be here today.
I would be worried about any lipo Battery that puts out huge amps in DC and always treat them carefully. I have a 75v 18650 20R pack myself with a 50 Amp limit BMS and it bothers me because i know what it can do if it was to release all its energy into someone that it could kill you Dead instantly.
Our Batterys we use do have the potential to kill or seroiusly Lame a person if not treated with respect.
ITS NOT THE VOLTS THAT KILLS YOU BUT THE AMPS WEATHER IT BE AC OR DC CURRENT
I did end my caree as an electrician when i was hooking up a 3 phase motor and my idiot boss flicked the breaker on after taking the do not remove tag off and hit me with 415 and i got hooked up for a few seconds with potentially 415V and cables that could draw over 150 Amps and i went down and cant remember a thing until the next day in Hospital.
The doctors told me it all has to do with your heart beat and when the heart is fully contracted that is when you are at most risk of it not starting back up because of the rythm of your heart cant expand due to the current in your body so your heart stops beating. You have to be very unlucky with the timing for this too happen otherwise alot more of us would not be here today.
I would be worried about any lipo Battery that puts out huge amps in DC and always treat them carefully. I have a 75v 18650 20R pack myself with a 50 Amp limit BMS and it bothers me because i know what it can do if it was to release all its energy into someone that it could kill you Dead instantly.
Our Batterys we use do have the potential to kill or seroiusly Lame a person if not treated with respect.
ITS NOT THE VOLTS THAT KILLS YOU BUT THE AMPS WEATHER IT BE AC OR DC CURRENT
