Are "protected" cells really that important?

[Hot Brass]

Hi:
My second light takes a single 18650 cell,so I was looking at the price difference between a "protected" cell and a "unprotected" cell and noticed there is quite a price difference between the two.
I can see using a 'protected' cell when being charged on maybe a $3.00 Dollar Store charger,but if I were using,say an Xtar WP2 II charger,or maybe even monitoring the charging process and checking periodically with a DVM so that the batt is not being over-charged,can I "get by" with using an unprotected AW 18650 cell?
Is the 'protected' cell used to protect itself from being over-charged or being discharged too fast? Thanks,Hot Brass

 

[HKJ]

Hi:
My second light takes a single 18650 cell,so I was looking at the price difference between a "protected" cell and a "unprotected" cell and noticed there is quite a price difference between the two.
I can see using a 'protected' cell when being charged on maybe a $3.00 Dollar Store charger,but if I were using,say an Xtar WP2 II charger,or maybe even monitoring the charging process and checking periodically with a DVM so that the batt is not being over-charged,can I "get by" with using an unprotected AW 18650 cell?
Is the 'protected' cell used to protect itself from being over-charged or being discharged too fast? Thanks,Hot Brass

The protection does prevent both over charge and over discharge, the last part is important in some flashlights. If you once over discharge a battery it will loose capacity and be more unsafe!

It might be a good idea to shop around for the price on a protected battery, but remember to compare batteries with the same cell inside!

 

[Norm]

A protected cell is also protected against short circuits.

Norm

 

[Hot Brass]

Thanks to all who replied...... I have another question?...I see some 18650 advertised as "flat tops"....are they all (AW) flat-tops and do I have a choice between "button-tops" and "flat top" and what are the main differences and uses,not counting the obvious? Thanks,Hot Brass

 

[HKJ]

Thanks to all who replied...... I have another question?...I see some 18650 advertised as "flat tops"....are they all (AW) flat-tops and do I have a choice between "raised-top" and "flat top" and what are the main differences and uses,not counting the obvious? Thanks,Hot Brass

The 2200mAh AW is not a flattop. When manufactured all LiIon batteries are flattop, but they do not work in all flashlights, due to connection problems. Many dealers add a button top to the cell to fix this problem, but it makes the battery slightly longer.

I would suggest you check my battery reviews, you can find all of them on my website, they specify both top type and length of battery.

 

[Hot Brass]

The 2200mAh AW is not a flattop. When manufacturer all LiIon batteries are flattop, but they do not work in all flashlights, due to connection problems. Many dealers add a button top to the cell to fix this problem, but it makes the battery slightly longer.

I would suggest you check my battery reviews, you can find all of them on my website, they specify both top type and length of battery.

Thanks! Very interesting reading indeed! So when I am in the market for a particular 18650 battery,I need to first check my light to see which battery type will work,be it flat top or button top? My light only use one 18650 battery. Thanks,Hot Brass

 

[HKJ]

Thanks! Very interesting reading indeed! So when I am in the market for a particular 18650 battery,I need to first check my light to see which battery type will work,be it flat top or button top? My light only use one 18650 battery. Thanks,Hot Brass

Yes, you need to check what battery type will work, this is usual very easy to do. If the plus connection in the light is slightly raised, it will work with flattop. You also need to check that the battery will fit, both length and diameter. Diameter is seldom a problem on lights designed for 18650, but length sometimes is.

 

[Hot Brass]

Yes, you need to check what battery type will work, this is usual very easy to do. If the plus connection in the light is slightly raised, it will work with flattop. You also need to check that the battery will fit, both length and diameter. Diameter is seldom a problem on lights designed for 18650, but length sometimes is.

Thanks,Hot Brass

 

[jasonck08]

It's the same concept as having airbags in your car. Protected cells are to protect against the unexpected, just like airbags.

 

[CMAG]

Check if your lamp's driver has a built in low volt cutoff and you have a good hobby type charger and you are lipo savvy and use your head you are good
simply said its as safe as you make it
Imo protected cell can give some false felling of security
like jasonck08 used the air bag example there are those out there who think air bag I don't need a seat belt of course both is best and I use protected cells but still handle with care and respect
last I sound like a broken record around here but three words I have for you Lipo Charging Bag

 

[lwknight]

Using quality and highly recommended cells can't be stressed enough. The protection can work against you too. I have some ultrafire 3000 mah cells that I probably don't get 1200 mah worth out of because they cut off at 3.7 volts.
The 3.7 volts is a nominal voltage and many cells are just fine to discharge to 2.8 or lower according to manufacturers specs.
Already I have had Eagletac cells out last the ultrafire at least double. I did not test them to the cut off point but they did not cut off at 3.6 or 3.7 whatever volts like the cheapies did.

Also cheapie pcb,s sometimes will not reset no matter what you do.

 

[yellow]

easy route:

who asks ... should use protected as is not aware of the risks
;)



as to flat-top: makes the cells shorter, so in a very extreme case the cells will fit into the light (they are more like 18670, not 18650 and ...)
When Your light has a raised positive contact, flat does work.
(when Your light has a spring on that side, even heavy bumps dont change the output level, so, when possible, take the one with the spring)

 

[Hot Brass]

Thanks everyone! Hot Brass