Will magnets mess with li-ion charger?

[johnny13oi]

Hey guys, I just bought a nano li-ion charger and wanted to make make an adapter for it so I can also charge other sizes of li-ions. Well, what I was wondering was if magnets messes with the electronics inside of a li-ion charger? Like would there be any adverse effect of having magnets really close or touching the terminals on the charger?

 

[VidPro]

should not effect it, unless they are moving back and forth and all really fast
the biggest effect something like that will often have is a reduced connection, just one more connection in the works, that may or may not connect well.

 

[johnny13oi]

should not effect it, unless they are moving back and forth and all really fast
the biggest effect something like that will often have is a reduced connection, just one more connection in the works, that may or may not connect well.

Thanks, I thought that there might be like coils or something inside and that the magnetic field might mess with it. And what kind of resistance would mess with the charging algorithms or speed? Would I be okay if I keep it under .5 ohms? Or do I need less?

 

[VidPro]

i donno.
if i remember right, the nano (li-ion) charger uses a very simple routine that ammounts to a voltage max.
so a reduced connection (of any sort) should never cause an overcharge state, it just might take longer to charge, look like it is charging and isnt, or start and stop charging.

if your resistance was below one ohm, nothing should change cept the charge rate by a little bit.
usually a loose(r) connection is vastly changing unreliable resitance, not a specific measurable ammount.

from experience, trying to wedge things between the battery terminals in chargers has sometimes resulted in a loose unreliable connection.

from reading here, most people are doing FINE with the shiney metal magnets in the LI_ION chargers.

a loose connection would mess with terminations and smart chargers more on ni-?? type chargers, where it could restart a charge sequence, or change the charge current from reset. also could be a problem with really smart fast li-ion chargers that do have sofisticated routines.

 

[DM51]

Hey guys, I just bought a nano li-ion charger and wanted to make make an adapter for it so I can also charge other sizes of li-ions. Well, what I was wondering was if magnets messes with the electronics inside of a li-ion charger? Like would there be any adverse effect of having magnets really close or touching the terminals on the charger?

Magnets use as connectors will not adversely affect the charge.

The nano-charger is a low-power unit, designed for small cells (available in AAA or 123 sizes). It is a very useful, neat little charger. However it is not a very good idea to use it for larger cells, as it will effectively be delivering a trickle charge, which is not recommended for Li-Ions. Apart from anything else, it will take you a very long time to charge them.

 

[johnny13oi]

Magnets use as connectors will not adversely affect the charge.

The nano-charger is a low-power unit, designed for small cells (available in AAA or 123 sizes). It is a very useful, neat little charger. However it is not a very good idea to use it for larger cells, as it will effectively be delivering a trickle charge, which is not recommended for Li-Ions. Apart from anything else, it will take you a very long time to charge them.

The one I got charges at .45A, so would charging an 18650 2400mAh which people say is closer to 2200mAh be fine? That would only be like 5 hours or so of charging.

 

[DM51]

The published 0.45A may not actually be as much as that. You could test it with a DMM with the 18650 connected. If it does deliver 0.45A, that is ~0.2C, which is well below the recommended 0.5C - 1.0C, and as you say it should in theory take ~5 hours to charge. However you will find that the current drops right down towards the end of the charge, so this will prolong the process further.

Bear in mind it is not safe to leave Li-Ions on charge unattended. Babysitting a single 18650 on charge for such a long time is not a worthwhile activity IMO, and you may decide instead to get a larger charger that can do 2 cells independently at once.

The Pila IBC charger is the one to go for, if you eventually come round to this view.

 

[johnny13oi]

I am not sure if this is off topic but I was also wondering if this would work with a smart Ni-Mh charger? like use the same adapter wire to charge say larger cells than what the charger can physically take? Say I make my connections < .2 Ohms. Would that be sufficient for the charger to correctly sense the cut off voltage?

 

[VidPro]

the resistance (again) itself is not going to be a problem with the ni-?? charging, its if the resistance CHANGES during the charging, which will throw off the "smart" computer.
in the case of ni-?? chargers if that connections changes one tiny bit, the soo small voltage drop the computer is trying to read will be way off.
say the connection is "ok" via an ohm meter, but the connection itself is a few molecules of metal making contact, and when pulsed by the charger (each time) that molecule of connection , burps about, then the computer will go brainless on you from the disconnection.
that is why it is so hard to stuff a meter inbetween the connections (ammeter) on those computerised chargers, one small change effects the computers tight readings.
IF your connection is totally SOLID, totally unchanging, then it will work fine.

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there is nothing "wrong" with slow charging, any cells of any type that i can tell, i run a bank of 120+ li-ions charging well below any of those rates, and it has operated for YEARS non-stop charging and discharging DAILY without a single issue, and certannly without any safety issue.

it is Proper to (according to some li-ion specs) lower the rate of charge at the end of the charge cycle exactally like the lame voltage max charger does, the nano should be completly sufficient and safe to be able to charge 18650. read the li-ion specs, for your specific cells, there was always an indication to complete the charge to the ~4.25v MAX (depending on the cell) at a slower rate than the first 80% of the cell, probably for safety reasons.
i also think that this "slow down at end of charge" alogrythym that was supposed to be in these charges, had a bit to do with the fact that , the se same single cell specs would be used to create charge alogrythyms for multiple cell type series sets, which could be out of balance.


ALTHOUGH, it is indeed more desirable to charge faster and pound the chemicals back into place , the actual "BEST" charging alogrythim according to a univeristy study was a 50-50 1min on off pulse charging of very high values. unfortunatly because nobody adopted this method, it was not widely tested, but i tested it and still do.

When people start FIRES from fast charging, and most INDUCED fires are accomplished from fast charging, i see no reason to condemn slow (but adequite) charging rates , untill they are also starting fires.

i could go on, but i have tested fully DAMAGED heating li-ion cells at low charge rates, and i could not get them to unseal, let alone fire. the same cells could be fast charged and the heat would have reached critical, and probably just anode disconnected the cell, as they had proper protections.

i would never call anything "THE answer", but i certannly would not condemn that which works and that which would be "more safe".

The answer were left with , is to read the exact specs for any cell that your going to use in any way.

the li-ion cell is NOT a ni-mhy which is being purposfully pushed to a overcharge state to reach a voltage drop occurance for visable termination via a votlage drop, NI-?? type cells can also be Slow charged effectivly and safely, but to be SMART charged, the computer junk has to see a V-Drop.