18650 lithium cell need help understanding risks

[kc8adu]

Re: 18650 lithium cell need help understanding risks

if you dont need the capability to do a 6s li-ion the older one can be a real bargain.
they are backed by a company with real support too.
one of mine had a warped panel that made the buttons act up.
1 call got a parts kit sent and i fixed it myself in like 10 minutes.

[infringer]

Re: 18650 lithium cell need help understanding risks

looked up the triton the other day actually seems decent for sub 200.00 piece of equipment.

[kc8adu]

Re: 18650 lithium cell need help understanding risks

the tablet battery likely has a protection board.
the battery will turn back on when you charge it.
the triton i use starts at a low current to soft start a possibly overdischarged battery.
it has never failed to turn the protection board on.

[infringer]

Re: 18650 lithium cell need help understanding risks

@BUDM what brands of equipment are you using just out of curiosity?

I got my small charger from xtar works like a champ charges well but slow... but it is compatible with the following has screw in negative terminals to adjust for sizes of the following 16340 14500 18650 18700 so it covers a range of lithium based cells.

I am half tempted to opt for a boost charger and a decent variable power supply I've needed one for some time but the last time I had a decent amount of money to blow I opted for a techtronix scope older model but 500mhz would love to have a decent supply and the one amp charge would be nice as well... Under close supervision of course.

[infringer]

Re: 18650 lithium cell need help understanding risks

@ the tablet user what tablet is it ? Please provide a model and such if possible so I could verify for you usually there is an yellow light for charging but there is no specific standard that has been set for indication lights usually a blinking red light is a power issue unless we are talking PS3... But, in any case it would help if you provided more info I have seen other colors used for status indicators... Would a wall wart work quite possibly it would the only problem I see is it may take a lot longer and may not be as safe to use do not leave it unattended for too long... Usually higher amperage is better because the circuit will only draw the power it needs I think most laptop bricks are in the relm of 4 amps and technically the charger will be safer to use as you have to worry about chargers heating up and catching fire as well. What ever you do though research it well nothing like a burnt down house my uncle had an electrical fire due to a faulty load center that was recalled was not a cool deal at all. Many things he worked years to achieve down the tubes then he wound up with lots of health issues shortly after and wound up getting laid off things can go south in a hurry I guess is the moral try and be as safe as you possibly can!

PS I accept not responsibility for your neglect to act with severe caution!

Beyond this I would say knowing the model would help best! Then go gather data about the model your wall wart should have a rating for the output but you should be safe with the proper voltage and amperage the charging circuit on the laptop will do the rest providing it is good.

And power jacks are dirty cheap on ebay but at times waiting on the slow boat from china sucks! So what I'll do is find a junker and salvage the parts for this type of item either use a solder sucking bulb or one with a vacuum pump ( Love these but expensive) or you could use some braided copper AKA solder wick and pop it off the board and replace. A lot of times when the jack is busted off it has a damaged center pin or the plastic inside is all busted off...

[budm]

Re: 18650 lithium cell need help understanding risks

I use variable power supply to charge the unknown condition Li-ion, I set the max constant current to about 100mA and limit the max voltage about about 4V~4.2V, that way if it has shorted cell, the max current will be only 100mA, mast fast charger will force over 1A into dead cell so the cell will get very hot and can be dangerous.
I will have to find that MAKITA batteries pack, do not remember where I put it at this point.

[cheapie]

Re: 18650 lithium cell need help understanding risks

I have a camera that had been in storage for so long that the battery (Li-ion) was reading 0V (most likely the undervoltage protection had engaged). The camera would not charge the battery. I made a simple current and voltage limited power supply and ran about 800mA into the (1150mAh) battery for about half an hour. The camera then powered on.

[selldoor]

Re: 18650 lithium cell need help understanding risks

Hi Clearly Infinger you have done quite bit of research into this, so you may be able to answer this query saving me hours?

I have just aquired for free a faulty tablet in which among other things the power socket had been broken and pushed completely off the board.

I have managed to rebuild the socket and fitted it to the board.

Battery seemed to be completely flat - not a flicker on my meter. Anyway It did not come witha power lead so I have tested it with a multivoltage walwart set at the correct voltage and polarity and it does power up the tablet and when powered down a led flashes red ( Of course I have no idea what that means but hope it is recharging. I have however bottled it in case I damage the battery.

Question is can I recharge a lion battery with this type of multicharger will the "control" be in the battery or does it have to have a "special" lion charger.

EDIT - May have answered my own query -albeit with another question.: The batteries are still in the tablet not being charged externally so does the tablet provide the "control" required

[infringer]

Re: @budm

@BudM

The makita thing sounds like a fun project do you have any information or close ups of the board to look at?

I would bet it is an SMT chip that can either be replaced or reset somehow it depends how they do it if they blow a fuse in some OTP memory then you would need to find a way to put it into factory mode to reprogram the memory or it may not be possible at all and it may just have to be replaced I think it is a poor choice to do this it causes conditions that drive the costs skyward its not like we have an unlimited supply of lithium so there should be conservation laws in place for this type of thing...

Personally I think they should require all manufactures to provide swappable cells for their batteries using a socket like a AA socket this would not only make it cheaper to fix your battery but it would make it more safe with less incidents...

I guess I just don't get it they do stuff like this intentionally to make more money under the guise of safety when in truth you are making it less safe there will always be someone that will try I think they should standardize all packs and start selling cells call me ignorant or crazy but it makes since to me "in the name of safety"

Whats more dangerous then throwing a soldering iron to these cells?

Not a whole heck of a lot and its harder then heck to get the solder to stick correctly as well requiring you to heat it up several times sometimes even after a quick sanding.

Anyhow I am interested if anyone does figure out the whole makita pack issue I wonder if other packs use a similar protection measure cause I have a battery with perfectly good cells except for one and I replaced it with a good working cell it shows that it is charged on the charger but when I throw it in the drill it does not work I didn't have time to test and analyze everything but it appears to me that either the board is bad or something similar has happened ... It is a ryobi pack...

I'll have to look into this a bit more could just be a bad component I suppose but it is showing voltage out of 20.1v which should be good .... but like I said could be something I'm missing on the board that went south not too familiar with it all I just started looking into it within the last week good to know about makita packs no wonder they are everywhere being sold as parts units. INR IMR based batteries should do for most all drills might be a good source for working cells for other packs if you get annoyed with their business practices.

[infringer]

Re: 18650 lithium cell need help understanding risks

yeah may be oddly I was able to recharge some cells that were showing 0v 4 out of 5 of them actually one of them would not go above 1.3v and started getting warm I monitored the thing with a meter and a IR thermometer the whole time it was charging just to be safe so hours of looking at batteries is not my idea of fun lol but my rig was primitive a meter and a 5v 500ma charger hacked up with some gator clips screwed to a hunk of 2x12 the voltage held at 3.6v and it is about 9hours that has passed so I assume the cells are still good and they just fell asleep well 4 out of 5 of them. We will see I got a 18650 usb charger on order from xtar to safely top them off using the word safely loosely cause I will have to pay attention to it and make sure it doesn't overcharge the cell I will likely charge inside of an old computer case just to somewhat contain anything that may happen from topping them off but the cells look as good as new or I would not have even attempted it.

Finally I will say that the cell will not take a charge if it shows 5 v and does not change when your leads touch the battery's anode and cathode.

Do not try this I take no responsibility for anyone trying this I did this in a well contained and safe area with a fire extinguisher near by that is suited for this type of fire. Do not try it at home!

[kc8adu]

Re: 18650 lithium cell need help understanding risks

sounds like he is simply retraining the fuel guage chip.
worn out cells just get worse the more you mess with them.

[infringer]

Re: 18650 lithium cell need help understanding risks

http://www.overclockers.com/forums/s...d.php?t=467302

Interesting thread...

[kc8adu]

Re: 18650 lithium cell need help understanding risks

i just use a hobby charger.my triton2 eq does just fine.

[budm]

Re: 18650 lithium cell need help understanding risks

I have yet to find out how to reset the chip so the Makita charger will recognize the rebuild pack.
http://www.candlepowerforums.com/vb/...-LXT-batteries

[barry wilkins]

Re: 18650 lithium cell need help understanding risks

Hi I rebuilt a Makita 14 volt battery with 4 cells that came from a laptop battery .I would have liked to use 8 cells to give me twice the power ,but there were only 6 cells in the battery. The drill will work for about 5 mins. with these cells ,it draws 3 amps.
At the moment I am designing a charger after I have finished this ,I am going to look at some Sanyo cells from a UK supplier ,you can get some cells that are intended for high discharge rates of 10 Amps so I might go for them.

[budm]

Re: 18650 lithium cell need help understanding risks

Good power tools will have good protection in the batteries pack (not just batteries in plastic casing and terminals) and in the charger. I open MAKITA batteries pack and it has PCB with lots of power MOSFETs and IC, etc. also.
http://www.siliconmethod.com/li-ion.html

[budm]

Re: 18650 lithium cell need help understanding risks

http://www.powerstream.com/li.htm
http://liionbms.com/php/wp_lovtg_cutoff.php

[domas]

Re: 18650 lithium cell need help understanding risks

http://batteryuniversity.com/learn/a...oltage_cut_off

i do not think that this is applicable for li-ion cordless tool controllers, is it? I have a feeling that their controllers are way less complex. Aren't they?

[infringer]

Re: 18650 lithium cell need help understanding risks

of course this is just theory furthering my knowledge and making sure I am understanding what I read thank you all for the affirmations on my theory... While I plan on using the correct cells for safety reasons of not getting my hand blown off or starting the house on fire as has happened I think it is good to have an understanding of battery storage technologies in this day and age.

[kc8adu]

Re: 18650 lithium cell need help understanding risks

most of the packs run 2 or 3 and some even 4p.so the load gets shared among the paralell groups.
i rebuilt some makita packs with panasonic 2900's and have beat them up good.
like running the drill near stall for long periods.
no problem.
but if you do this and it imitates a roman candle i am nor responsible!