charging in series.

[ned]

have a batt charger that can charge 1-26 cells and can charger multiple identical batt packs in series.
i was just wondering how i would go about joining packs in series?
heres what i think would work, but would like a second opinion before i blow up a batter or two and a charger.


e107_files/public/142_batt_diagram.jpg
<span class='smalltext'>[ 142_batt_diagram.jpg ]</span>

[JD]

i think ur + on ur charger goes to the + on the battery ?

[Matt]

JD is right. fix that, and it will work.

the issue is when it comes to detecting when to finish the charge. chargers detect a slight voltage drop and cut off. across a 6 cell pack its sloppy enough because if one cell drops voltage quicker than the other 5, then the pack is cut early. this problem is amplified more across 12 cells running in series. if you have that 1 cell drop voltage the charger sees the overall voltage drop, cuts your charge and you have two pretty crappy packs that wont be charged to the max.

hope this makes sence?

matt.

[JD]

has there ever been anyone testing with like diodes, to prevent one bad cell from dropping the power of a whole pack ?
<span class='smallblacktext'>[ Edited Wed Jun 28 2006, 08:05PM ]</span>

[ned]

i found this while searching google
http://www.freepatentsonline.com/5932990.html

dont know who makes it, but its patented.

hmm, im getting some really mixed answers here.
you guys are telling me to change the wires around, and then the guys on beat your truck and nitrobashers are telling me that drawing is fine. also, im getting told that charging in series in NOT reccomended unless the battery packs are run in series together at the same time.

argghhh...im confused.
maybe it would be better to just get a dual charger.

[JD]

ask them to take a close look at the polarity, they might not be looking at that and just looking at the overall design

[ned]

so this is better.



e107_files/public/142_batt_diagram23.jpg
<span class='smalltext'>[ 142_batt_diagram23.jpg ]</span>

[ned]

so what about this for doing 4 packs?


<span class='smallblacktext'>[ Edited Wed Jun 28 2006, 10:51PM ]</span>

[ned]

try again

edit..grrrr
<span class='smallblacktext'>[ Edited Wed Jun 28 2006, 10:57PM ]</span>

[JD]

between the batterys u go + --> -

otherwise u'll short them.
<span class='smallblacktext'>[ Edited Wed Jun 28 2006, 10:53PM ]</span>

[JD]

:D

e107_files/public/158_pic.png
<span class='smalltext'>[ 158_pic.png ]</span>

[ned]

heres the 4 pack array

e107_files/public/142_batt_21.jpg
<span class='smalltext'>[ 142_batt_21.jpg ]</span>

[ned]

and heres the 2 pack

e107_files/public/142_batt_diagram23.jpg
<span class='smalltext'>[ 142_batt_diagram23.jpg ]</span>

[JD]

yup