Breaktru Forum

eCigarette Forum => Battery => Topic started by: jester on June 15, 2012, 09:57:48 AM

Title: adding a fuse
Post by: jester on June 15, 2012, 09:57:48 AM
i would like the best way of adding a fuse most of my bats are protected but i would like to add a fuse and if i use unproected it would be safer :help:i would like a easy way to learn from
Title: Re: adding a fuse
Post by: jester on June 15, 2012, 10:01:30 AM
when i say unproteced i mean bats like to ncr18650a not cheap rubbish thank you jester
Title: Re: adding a fuse
Post by: Breaktru on June 15, 2012, 05:57:54 PM
See Craig's post: http://breaktru.com/smf/index.php/topic,265.msg2022.html#msg2022 (http://breaktru.com/smf/index.php/topic,265.msg2022.html#msg2022)

Where to put the fuse:
........, you should be able to stick a fuse between the positive terminal and switch on one of the cells to keep them from swapping too much current.  You could probably just put it in line with the positive terminal on one cell and the switch.


Hey Jimmy, sorry I didn't respond to your post of the fuses. I was waiting for someone other than me to jump in. Seems only a couple of members participate on posting and answering.

Anyway, I use a 3A hold and 5.1A trip rated PTC.

Note:
On a Buck OKR or 08100w the battery current is lower than the output current. On a boost 04050c or DNA, the battery current is higher than the output current.

Mouser UK:
http://www.mouser.com/ProductDetail/Littelfuse/16R300GU/?qs=ZSIFh4sPSRpz2qvfZJEcFPldogESebHZfRGfvdKFf1Y%3d (http://www.mouser.com/ProductDetail/Littelfuse/16R300GU/?qs=ZSIFh4sPSRpz2qvfZJEcFPldogESebHZfRGfvdKFf1Y%3d)

http://www.mouser.com/ProductDetail/Littelfuse/2920L300DR/?qs=PWhpLWeW8wfzjY7M%252bgs3hHv%2fvohYHDEdQksRj%252bo%2fV%252bo%3d (http://www.mouser.com/ProductDetail/Littelfuse/2920L300DR/?qs=PWhpLWeW8wfzjY7M%252bgs3hHv%2fvohYHDEdQksRj%252bo%2fV%252bo%3d)

http://www.mouser.com/Circuit-Protection/PTC-Resettable-Fuses/_/N-5g3e?P=1z0rw2m&Keyword=resettable+fuse&FS=True (http://www.mouser.com/Circuit-Protection/PTC-Resettable-Fuses/_/N-5g3e?P=1z0rw2m&Keyword=resettable+fuse&FS=True)
Title: Re: adding a fuse
Post by: jester on June 15, 2012, 06:23:00 PM
so if i was using imr bats and okr t10 would go with bat or the okr amp ratting cheers jimmy
Title: Re: adding a fuse
Post by: jester on June 15, 2012, 06:34:30 PM
i am trying to post as much as i can for all to read thats  how i learn :thankyou: :thumbsup:jimmy
Title: Re: adding a fuse
Post by: Breaktru on June 15, 2012, 07:22:26 PM
so if i was using imr bats and okr t10 would go with bat or the okr amp ratting cheers jimmy

You can use the ratings I posted previously. You will never trip the fuse vaping. You will be protected in case of an atty short or one of the batteries failed causing excessive amperage in the good battery.
Title: Re: adding a fuse
Post by: jester on June 15, 2012, 07:25:57 PM
thats magic thank you  :rockin smiley:jimmy
Title: Re: adding a fuse
Post by: ChainVaper on June 17, 2012, 11:07:53 AM
With all the press on the dangers of exploding batteries, I now put a fuse in everything. Have we all become paranoid  :Thinking:
Why take a chance it's simple to do  :yes"
Title: Re: adding a fuse
Post by: Breaktru on June 17, 2012, 11:11:52 AM
With all the press on the dangers of exploding batteries, I now put a fuse in everything. Have we all become paranoid  :Thinking:
Why take a chance it's simple to do  :yes"

Yeah Chain and up until a few months ago I don't remember anyone adding a fuse. I think it was Craig who convinced me to use fuses. Thanks buddy.
Title: Re: adding a fuse
Post by: CraigHB on June 17, 2012, 02:46:20 PM
Hehe, welcome.  I always use fuses.  If you look at the PCB for my mod (posted in another thread here), you'll see two SMD PTC fuses in parallel at the very top left corner of the board.  There's two to reduce losses due to resistance.  They're actually a backup since the mod senses over-currents and shuts down input power much faster than the fuses can react.

When using a buck converter or a linear regulator, they do have the ability to shut down input power if there's an over-current condition.  Boost converters are not able to do that.  It's because boost converters can only increase output voltage, not reduce it.  So, there is "some" protection with a buck converter or linear regulator.  It's still a good idea to add a fuse as a backup.  Can never be too safe with these Li-Ion batteries.