* THE FORUM FOR ALL THOSE INTERESTED IN BUILDING AND OPERATING MODEL SUBMARINES *



Join the AMS - Registered Forum users can become members of the AMS and it's free ...... To join register on the forum first then follow the forum link to our membership form which is on our website


For further details of any events shown here also see the "Shows and Events" section on the forum

That's it for events for 2019. Let us know what you have planned for 2020.

.

,
,
.

. ,

;:

,./
.
.,,,

.

.

,,,,

,

Who is online?

In total there is 1 user online :: 0 Registered, 0 Hidden and 1 Guest

None


Most users ever online was 180 on Tue Nov 05, 2019 6:03 am

Latest topics

» today's work
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyToday at 4:32 am by merriman

» Pinger 2 - Ultrasonic
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyTue Dec 03, 2019 2:32 pm by david f

» gear-splitter
Simple, elegant voltage shut off - Lipo protection perhaps? EmptySun Dec 01, 2019 8:16 am by merriman

» The SubDriver becomes Modular
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyTue Nov 26, 2019 3:12 pm by merriman

» upgrading the SSY 1/96 ALFA kit
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyWed Nov 20, 2019 3:05 am by merriman

» Beck's model marine
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyWed Nov 13, 2019 6:27 pm by Beck’s model marine

» Beck’s model marine
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyWed Nov 13, 2019 9:16 am by Beck’s model marine

» Industrial display of COLLINS control-room
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyMon Nov 11, 2019 2:04 pm by merriman

» German Hecht XXVIIA in 1/17 scale
Simple, elegant voltage shut off - Lipo protection perhaps? EmptyTue Nov 05, 2019 3:48 am by george jure

Statistics

Our users have posted a total of 10993 messages in 1805 subjects

We have 827 registered users

The newest registered user is pegasus72

    Simple, elegant voltage shut off - Lipo protection perhaps?

    david f
    david f
    AMS Treasurer

    Posts : 2054
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria

    Simple, elegant voltage shut off - Lipo protection perhaps? Empty Simple, elegant voltage shut off - Lipo protection perhaps?

    Post  david f on Wed Feb 15, 2012 8:53 am

    A rather interesting link from John Main of C for Microcontrollers.

    http://www.best-microcontroller-projects.com/rechrgbatprotect

    Let us know if you use the circuit principle. I already use a MOSFET in a slightly similar way as an on/off switch (Triggered by magnet and reed switch.)

    David
    johnrobinson
    johnrobinson
    Guest

    Posts : 97
    Join date : 2011-06-10

    Simple, elegant voltage shut off - Lipo protection perhaps? Empty LIPO PROTECTION PERHAPS LOL

    Post  johnrobinson on Wed Feb 15, 2012 7:39 pm

    HI David
    Problem with lipos is you need to monitor each cell in the pack because one cell will always go down in voltage first, you should not really take a cell down below 2.95V or you risk damageing the cell. The circuit that you showed will just monitor the hole pack and that is not the way to do it.

    If you had a 3 cell pack of lipos just say 1 cell was at 3.5v and the next was at 3.5v but the last cell was at 3v the 3v cell should be switching the power off to speed controller or what ever but if you put 3.5 and 3.5v together would make 7v plus 3v for the cell that should be turning the power off add voltage up it comes to 10v but if you carried on discharging pack down to 9volts the cell that was at 3volts when the pack voltage was at 10volts by the time it got to 9volts would now be damaged and that is how you would slowly cream cracker a lipo pack. This is just the basic idea that's why it is the best thing to monitor all cells in the pack, say you went to 10 cells now gets worse and becomes more important to monitor the cells
    SUB JOHN
    david f
    david f
    AMS Treasurer

    Posts : 2054
    Join date : 2010-11-10
    Age : 69
    Location : Cumbria

    Simple, elegant voltage shut off - Lipo protection perhaps? Empty Re: Simple, elegant voltage shut off - Lipo protection perhaps?

    Post  david f on Thu Feb 16, 2012 9:06 am

    Hi John,

    In a perfect world it would be best to monitor each cell but it can make it much more complicated.

    I think you are speaking more of aircraft applications - many cells and drawing very high amps.

    The lipos I have used in subs for several years are only 3 cells and I only draw about an amp. In these circumstances I suspect you don't get big voltage differences between cells and I always balance charge them. I also don't push my luck and sail for too long (I have never had a low voltage alarm.)

    So I think in the absence of anything else this type of circuit would give your Lipo a good level of protection.

    David

      Current date/time is Sun Dec 08, 2019 8:34 am