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LiPo Battery protection with WH-296S2A3?

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#1 Sat, 2015-12-05 19:19  

LiPo Battery protection with WH-296S2A3?

Last seen: 7 hours 3 min ago
Joined: 21 Sep 2015 - 12:13

A while back I got a couple of these to protect LiPo batteries from over discharge/charge. I am really only interested in the over discharge feature as I alreaddy ruined one expensive LiPo battery pack by over discharging, not a hard thing to accomplish..

So, the question is, just how do I hook this thing up? Can I do this with my Turnigy LiPo battery? The instructions (below Pictures) are a bit confusing and in broken english. Any help I can get will be appreciated.

 This Lithium ion phosphate battery protection PCB protect single Lithium ion batteries.
 Protection is necessary, as Lithium ion phosphate batteries will damaged when they are shorted circuit, overcharged or overdischarged.
 3A continous current.
 Suitable For:2 cell of nickel, cobalt and manganese lithium, lithium cobalt oxide, manganese lithium-ion rechargeable battery, 2 cell lithium polymer rechargeable battery string.
 Wiring instructions:
 �� B + connected battery cathode;
 �� B- take battery;
 �� MB then the battery 1 and the battery before connecting point 2;
 �� P + connection charge / discharge upright pole (charging terminal / discharge end share);
 �� P- take charge / discharge end of the negative electrode (the charging terminal / discharge end of the share).
 (1) Please note that the input and output voltage, and load current conditions for power protection board does not exceed the allowable power consumption specifications.
 (2) may occur when connecting the battery case can not be discharged. In this case, connect the charger can be restored to normal operation.
 Case (3) battery overcharge and over discharge the battery becomes mixed up with the state of the overcharge and over-discharge state, it is impossible to charge and discharge.
 (4) The protection board the built-in electrostatic protection circuit, but please do not apply an electrostatic discharge protection circuit than the protection board.
 Model: WH-296S2A3
 Rated voltage: DC7.4V
 Charge voltage: DC: 9V CC / CV
 Maximum continuous discharge: 3A
 Overcharge detection voltage: 4.29 ± 0.025V
 Over-discharge detection voltage: 3.0V ± 0.10V
 Overcurrent detection current: 5.7A ± 0.3A
 Resistance: ≤35mΩ
 Working temperature: -40 ~ + 52 °C
 Size:3 x 0.6cm/1.18 x 0.24"(L x W)


Sat, 2015-12-05 19:39  

I found a bit more info

Last seen: 5 months 2 days ago
Joined: 22 Sep 2015 - 18:04

Pin Assignment:
B+: Battery Positive
B-: Battery Negative
MB: Connect Battery 1 "-" & Battery 2 "+"
P+: Output/Charging (share use)
P-: Output/Charging (share use) 
Remark: You must connect DC charger at 1st time for soft power up the module.

The wiring diagram



But to me it looks like this is to protect it when connected to a charger?

Whoever said nothing is impossible never tried slamming a revolving door

Sat, 2015-12-05 20:52  

so that brings the question...

(Reply to #2)
Last seen: 7 hours 3 min ago
Joined: 21 Sep 2015 - 12:13

so that brings the question, how to tap that center cell connection... I assume its the charger balencer connection for that, but which wire is the center tap?  I did find some info here, but still not clear, or does it matter, as log as it get the voltage level of one cell? ​



"Propeller Girl"
I tinker, therefore I am.....



Mon, 2015-12-07 10:39  


Last seen: 12 hours 4 min ago
Joined: 27 Sep 2015 - 14:54

My guess is you have a board designed to reside inside a dual cell LiPo package. 

Fri, 2015-12-18 08:18  

I've created a power distribution board incorporating this thing

Last seen: 7 hours 3 min ago
Joined: 21 Sep 2015 - 12:13

As yet in testing stages, hopefully it will work as needed. Since this little board was not intended to be used extranal and removable from a LiPo battery set, I found some extra challenges, one being that once the battery pack is disconected for some time, the board needs a "reset" so I addded a simple circuit to "jumpstart" it. I don't have a schematic to post as I did this all in my head, I'll draw one up at some point if it actually does work.



"Propeller Girl"
I tinker, therefore I am.....



Sun, 2015-12-20 16:07  

It works!

(Reply to #5)
Last seen: 7 hours 3 min ago
Joined: 21 Sep 2015 - 12:13

Today I ran the battery down for enough for the protection circuit to work, it shut down and saved my battery. At some point I'll draw up a schematic for my power board, I pretty much built from bits and pieces of notes. So, although this little board is intended for internal battery use, it can be used externally. 



"Propeller Girl"
I tinker, therefore I am.....



Fri, 2015-12-25 17:45  

Merry Christmas!

(Reply to #6)
Last seen: 7 months 1 week ago
Joined: 2 Oct 2015 - 18:36
Great work Rox! I recently made a portable RPi video player and fried a fair few Adafruit powerboost boards trying to get a solid battery charge/protection in place. I definitely need to copy your idea ;-)