How do i charge a LEAD ACID battery. - Page 3 - Electronic Circuits Projects Diagrams Free

bountyhunter · 7th October 2009, 03:39 AM

Quote:

Originally Posted by audioguru

RadioShack never had brand new goods. They sold factory rejects (seconds) and defective parts.

I have seen some of that too. The "Realistic/Shure" stylus I got was definitely imperfect. I took my stylus microscope down to the Radio Shack I bought it to show the guy. For fun, we opened every one they had in stock and they were all Shure rejects. They were functional, but the diamond tips were cut off center like a cone shifted off center of the center line of the rod.

I always assumed their stuff was functional rejects that makers wanted to dump to make money without tarnishing their name.

audioguru · 7th October 2009, 04:25 AM

Guess what?
RadioShack has been gone fron Canada for years because they ripped off so many people. Their parts were expensive garbage. Years ago the parts were good.

I bought a video cable there for about $16.00. Then I found exactly the same cheap Chinese one (same brand) at The Dollar Store for $1.00. I bought the one from The Dollar Store and returned it to RadioShack for a refund.

RCinFLA · 7th October 2009, 04:45 AM

It sounds like your batteries are gel cell lead acid. They float a lttle higher then regular lead acid (13.5 -13.8 vdc).

Number one thing on lead acid batteries is do not let them sit for months without periodic full charge.

Discharge converts lead to lead sulfate taking sulfuric acid from electrolyte and converting it to water. If left in discharged state the lead sulfate will crystalize which does not breakdown back to lead and sulfuric acid when recharging. There is some self discharge so charge needs periodic replentishment.

HATHA · 7th October 2009, 11:23 AM

hi Lopez
try this Battery charger circuit using L200. | Free Electronics Projects-Electronics circuits and hobby designs diagrams
i built some thing similar to that with l200 regulator. i use it for charge 12v motor cycle battery work perfect. use large heat sink for l200 even though it have thermal shutdown protection; its getting really hot

AtomSoft · 7th October 2009, 11:34 AM

thanks! found this:

STMICROELECTRONICS|L200CV|Voltage Regulator IC | Newark.com

only issue is the description doesnt match the image really

HATHA · 7th October 2009, 11:49 AM

Quote:

Originally Posted by AtomSoft

thanks! found this:

STMICROELECTRONICS|L200CV|Voltage Regulator IC | Newark.com

only issue is the description doesnt match the image really

is any thing i miss

AtomSoft · 7th October 2009, 11:52 AM

Thats the L200(CV) i though it would be hard to find but not. And really cheap ! heh thanks

indulis · 7th October 2009, 12:27 PM

Quote:

RadioShack never had brand new goods. They sold factory rejects (seconds) and defective parts.

Oh really....

RadioShack - Wikipedia, the free encyclopedia

audioguru · 7th October 2009, 03:10 PM

It is not surprising that Bell Canada now owns former Radio Shack stores (now called The Source) in Canada.
Radio Shack stores sold cell phones with Bell Canada contracts for many years.

k7elp60 · 7th October 2009, 04:06 PM

All it takes is one PB137, a transformer, A heat sink,a rectifier and a couple of capacitors to float or standby charge your batteries. The data sheet for the PB137 is attached. Even a Radio Shack 12.6 VAC transformer will work.
I have had good luck with the all enclosed Radio Shack transformers.

AtomSoft · 7th October 2009, 07:34 PM

hey ! a PB137 is like a LM317 set to 13.7v heh

dropout is about 2v to 2.5v so at 13.7+2.5 = 16.2v

so a 19v supply should do

audioguru · 8th October 2009, 12:13 AM

If you charge your little batteries at 2.4A (the typical output current of a PB137) then they might be destroyed.
With a 19V supply it will dissipate [(19V - 13.7V) x 2.4A=] 12.7w and will need a pretty big heastsink.
But if your batteries are old and discharged then they will not charge.

AtomSoft · 8th October 2009, 11:55 AM

who said i was charging at 2.4A? the max is 2.1A so i assume... 1.5A is good enough... hence the LM317
[(19V - 13.7V) x 2.4A=] 12.7w

would then be

[(19V - 13.7V) x 1.5A=] 7.95w

but dont i have to account for the 2v dropout?

19v-13.7v-2v*1.5A = 4.95w

audioguru · 8th October 2009, 06:49 PM

Sorry, the PB137 and the LM317 both have a typical output current of 2.2A, not 2.4A. I read the graph wrongly in the datasheet.
Their minimum guaranteed output is 1.5A.
The max current of some LM317's is 3.4A. That will blow up your little batteries.

AtomSoft · 8th October 2009, 08:24 PM

heh hence current limiting resistor.

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7th October 2009, 04:25 AM	#32
audioguru	Guess what? RadioShack has been gone fron Canada for years because they ripped off so many people. Their parts were expensive garbage. Years ago the parts were good. I bought a video cable there for about $16.00. Then I found exactly the same cheap Chinese one (same brand) at The Dollar Store for $1.00. I bought the one from The Dollar Store and returned it to RadioShack for a refund. __________________ Uncle $crooge

7th October 2009, 04:45 AM	#33
RCinFLA	It sounds like your batteries are gel cell lead acid. They float a lttle higher then regular lead acid (13.5 -13.8 vdc). Number one thing on lead acid batteries is do not let them sit for months without periodic full charge. Discharge converts lead to lead sulfate taking sulfuric acid from electrolyte and converting it to water. If left in discharged state the lead sulfate will crystalize which does not breakdown back to lead and sulfuric acid when recharging. There is some self discharge so charge needs periodic replentishment.

7th October 2009, 11:23 AM	#34
HATHA	hi Lopez try this Battery charger circuit using L200. \| Free Electronics Projects-Electronics circuits and hobby designs diagrams i built some thing similar to that with l200 regulator. i use it for charge 12v motor cycle battery work perfect. use large heat sink for l200 even though it have thermal shutdown protection; its getting really hot __________________ ----------------------------------------------------------------------------------- “We can't solve problems by using the same kind of thinking we used when we created them.” -Einstein -----------------------------------------------------------------------------------

7th October 2009, 11:34 AM	#35
AtomSoft	thanks! found this: STMICROELECTRONICS\|L200CV\|Voltage Regulator IC \| Newark.com only issue is the description doesnt match the image really __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics Last edited by AtomSoft; 7th October 2009 at 11:38 AM.

7th October 2009, 11:52 AM	#37
AtomSoft	Thats the L200(CV) i though it would be hard to find but not. And really cheap ! heh thanks __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics Last edited by AtomSoft; 7th October 2009 at 11:53 AM.

7th October 2009, 03:10 PM	#39
audioguru	It is not surprising that Bell Canada now owns former Radio Shack stores (now called The Source) in Canada. Radio Shack stores sold cell phones with Bell Canada contracts for many years. __________________ Uncle $crooge

7th October 2009, 07:34 PM	#41
AtomSoft	hey ! a PB137 is like a LM317 set to 13.7v heh dropout is about 2v to 2.5v so at 13.7+2.5 = 16.2v so a 19v supply should do __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics Last edited by AtomSoft; 7th October 2009 at 07:45 PM.

8th October 2009, 12:13 AM	#42
audioguru	If you charge your little batteries at 2.4A (the typical output current of a PB137) then they might be destroyed. With a 19V supply it will dissipate [(19V - 13.7V) x 2.4A=] 12.7w and will need a pretty big heastsink. But if your batteries are old and discharged then they will not charge. __________________ Uncle $crooge

8th October 2009, 11:55 AM	#43
AtomSoft	who said i was charging at 2.4A? the max is 2.1A so i assume... 1.5A is good enough... hence the LM317 [(19V - 13.7V) x 2.4A=] 12.7w would then be [(19V - 13.7V) x 1.5A=] 7.95w but dont i have to account for the 2v dropout? 19v-13.7v-2v1.5A = 4.95w __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics Last edited by AtomSoft; 8th October 2009 at 11:56 AM.*

8th October 2009, 06:49 PM	#44
audioguru	Sorry, the PB137 and the LM317 both have a typical output current of 2.2A, not 2.4A. I read the graph wrongly in the datasheet. Their minimum guaranteed output is 1.5A. The max current of some LM317's is 3.4A. That will blow up your little batteries. __________________ Uncle $crooge

8th October 2009, 08:24 PM	#45
AtomSoft	heh hence current limiting resistor. __________________ AtomSofts eBay Store AtomSoftTech: C18 TIPS & TRICKS v9 PDF Nokia 6100 Driver/Software My Name: Jason Lopez http://atomsofttech.info/ \| My YouTube Videos! My Favorite Store: dipmicro Electronics