Take care with your Ebike batteries...

[Pedalo]

I thought I was very careful with my ebike battery but obviously not careful enough. While swapping cables around my wedding ring brushed against a pair of connector contacts which happened to be wired through to the battery.

There was a flash of light, a 'puff' sound and then (luckily) the fuse blew - but sadly not before the surface of my ring melted and my finger burnt. It could have been a lot worse (especially if the fuse wasn't there) but it's made me realise that being careful isn't enough. You need to be super careful!

I thought I'd post here in the hope that others can learn by my mistake - after having a good laugh at my expense of course.

 

[morphix]

Damn sorry to hear that, glad you're not seriously hurt and the battery is ok..it's shame about your ring, but you can always replace it I guess. This shows how easily accidents with batteries can happen. I had an accident myself with a battery many years ago in my reckless youth days which nearly ended in tragedy. I was charging a battery and overcharged it and the thing exploded near my face.. I lost my eyesight and ended up going to the eye hospital in ambulance and spent the next 2 hours having bits of battery picked out of my eyeballs..not fun! I was without sight for a week, but no lasting damage, lucky for me.

 

[Pedalo]

Thanks Morphix. I'll try taking the ring to a jewellers as I think it may be repairable.

Your accident sounds much worse and it sounds like you were lucky not to be permanently blinded

 

[NRG]

I know just how much power these batteries have:

The guys on ES call it Kentucky Fried Finger:

I shorted out a small car battery many many years ago with a spanner, the amount of energy is really amazing, the battery terminal and spanner simply vaporised.

 

[John L]

OMG - some serious stories there! I for one didn't realise how careful I need to be - a timely warning.

NRG that looks really sore

If we're talking about charging I have another warning. The connector on my charger is the same as that of the charger for my wife's laptop. Yep you guessed it - my daughter not knowing any different plugged in the battery charger into the laptop and blew the laptop Expensive lesson! My own fault for leaving the charger close to the laptop - I was checking out the cost of a second charger online and needed some details from the charger. Should have put it away afterwards. Bummer.

John

 

[NRG]

it was! My own stupid fault for putting the same male connectors on + and - Doh! I use Powerpole connectors now

 

[morphix]

I know just how much power these batteries have:

The guys on ES call it Kentucky Fried Finger:

I shorted out a small car battery many many years ago with a spanner, the amount of energy is really amazing, the battery terminal and spanner simply vaporised.

Ouch that looks a really nasty burn there, or does it look worse than it is?

 

[jerrysimon]

A timely reminder guys. I remember when you did that NRG just as I was building mine

If you are building your own battery and using male/female connectors always put the female connector on the battery side.

Regards

Jerry

 

[monkoffunk]

The instantaneous current (for very short intervals) many batteries can provide is really rather spectacular. Take a 40AH 12V car battery for example, most can do say 400 cold cranking amps, which is to say it can supply 400A for 30s at -18C! In a short, at normal temperature, the instaneous amount of amps available, for a split second, is probably well over a 1000A

The AGM type of lead-acid battery can often hit 1000CCA, so they can provide massive amounts of current in a short under normal temps.

I'm not sure with Lithium's but I suspect they can also produce huge short term currents also in a short-circuit.

Your finger by the way! That looks proper painful. I remember such pain when as I kid I inadvertently made a "jam jar" pulsejet engine out of a small vinegar bottle and some methylated spirit and my finger was in the way. I had no idea what a pulsejet was, I created it by accident, I thought I was just messing with lighting a bit of meths.