How do i charge a LEAD ACID battery. - Page 2 - Electronic Circuits Projects Diagrams Free

AtomSoft · 6th October 2009, 01:41 AM

on page 12 this is what made a lot of sense to me and gives me ideas

Quote:

The recommended constant float voltage is 2.25-2.30
volts per cell. Maintaining this float voltage will allow
the battery to define its own current level and remain
fully charged without having to disconnect the charger
from the battery. The trickle current for a fully charged
battery floating at the recommended charge voltage will
typically hover around the 0.001C rate (10mA for a
10AH battery, for example.)
The float charger is basically a constant voltage power
supply. As in cycle chargers, however, care must be exercised
not to exceed the initial charge current of 0.20
x C amperes.

The box for batteries show initial current info and stuff so when i get it ill post my hypothesis on this...

Sceadwian · 6th October 2009, 01:45 AM

The stupidest simply method to charge a lead acid cell is the same method a car does. When the engine is running it outputs 13.8VDC. Attach a 13.8VDC regulated supply when not in use and you're all set. You can get more complicated, but it's primarily for more deeply discharged batteries.

audioguru · 6th October 2009, 01:48 AM

Quote:

Originally Posted by Sceadwian

The stupidest simply method to charge a lead acid cell is the same method a car does. When the engine is running it outputs 13.8VDC. Attach a 13.8VDC regulated supply when not in use and you're all set. You can get more complicated, but it's primarily for more deeply discharged batteries.

No.
Most cars charge the battery at about 14.4V. But the voltage is temperature compensated.

Sceadwian · 6th October 2009, 01:52 AM

Why 14.4v? Doesn't that cause excessive gassing of the battery?

MikeMl · 6th October 2009, 02:05 AM

Quote:

Originally Posted by Sceadwian

The stupidest simply method to charge a lead acid cell is the same method a car does. When the engine is running it outputs 13.8VDC. Attach a 13.8VDC regulated supply when not in use and you're all set. You can get more complicated, but it's primarily for more deeply discharged batteries.

The voltage on modern cars is more like 14.4 to 14.5V. However, they get by with this on the assumption that the car is running less than two hours per day. A flooded-cell, lead-acid automotive starting battery left on a constant-voltage charger set to 14.4V will be junk in a week (due to overcharge). 14.4V is ok for recharging, but you have to lower the voltage to a float voltage of 12.9 to 13.2V after the initial charging current drops below a few hundred mA. A flooded LA battery can be floated indefinitely at 12.9 to 13.2V.

Sealed AGM (VRLA) batteries are to be charged at 14.4 to 14.8V, and floated at 13.5 to 13.8V, adjusted for ambient temperature.

bountyhunter · 6th October 2009, 06:14 AM

Quote:

Originally Posted by Sceadwian

Why 14.4v? Doesn't that cause excessive gassing of the battery?

Most new systems are about 14.0V these days, tolerance about +/-0.5V. back in the 70's, Chrysler corp specified 14.4 and some others specified 13.8.

You don't want to leave one at 14V indefinitely because it does accelerate water loss. A car uses 14V to get fatser charge replacement after starting.

bountyhunter · 6th October 2009, 06:20 AM

Quote:

Originally Posted by AtomSoft

heh these are brand new batteries. I own 2 and i had a few customers come into my job at radio shack asking me where to get a charger and why dont we sell them.

So i decided to buy a couple and try to make a charger on my own and see how much it cost compared to commercial chargers then if possible create them and sell them outside/apart my job. Will be sold with no warranty/guarantee and has nothing to do with my job. I will sell it as cheap as possible while trying to make the money back from parts and something for time spent reading and learning this myself.

13v was my main choice. The batteries i have like a IDIOT i threw away the boxes which had a ton of info on them heh

Ill go and make a photo copy of the box at work and show you all along with my idea of how to charge it and my method and schematic and source etc...

I designed and published a temp compensated charger for lead acid that is cheap to build. You can have it if you want it since it's already been published. The text refers to a set point of 13.5V, but I adjust mine to 13.2V for my float charge application.

indulis · 6th October 2009, 12:18 PM

Some more reading if your interested....

AtomSoft · 6th October 2009, 02:50 PM

please remember these are not car batteries so there is a difference. I will post what i have later on today after work

MikeMl · 6th October 2009, 03:38 PM

Quote:

Originally Posted by bountyhunter

Most new systems are about 14.0V these days, tolerance about +/-0.5V. back in the 70's, Chrysler corp specified 14.4 and some others specified 13.8.

You don't want to leave one at 14V indefinitely because it does accelerate water loss. A car uses 14V to get fatser charge replacement after starting.

I guess GM hasn't heard this. My 2004 GMC K1500 pick-up still has the OEM Delco battery after six years. The running voltage at the battery terminals is 14.4V to 14.7V, depending on temperature.

My 2006 Toyota Corolla has 14.4V at ~70degF.

bountyhunter · 6th October 2009, 09:07 PM

Quote:

Originally Posted by MikeMl

I guess GM hasn't heard this. My 2004 GMC K1500 pick-up still has the OEM Delco battery after six years. The running voltage at the battery terminals is 14.4V to 14.7V, depending on temperature.

My 2006 Toyota Corolla has 14.4V at ~70degF.

14.4V is within the spec I posted which is 14 +/-0.5V. My 2003 Chevy Cavalier is right on 14V.

I don't know what they are using for nominal charge voltage anymore, but they may be playing around with dual rate to get faster recharge. I do know using higher than 14.5 (25C) is going to reduce battery life but they probably don't care. They may be compensating for an undersized alternator or whatever cheap thing they do to cut cost these days.

MikeMl · 6th October 2009, 11:36 PM

Quote:

Originally Posted by bountyhunter

14.4V is within the spec I posted which is 14 +/-0.5V. My 2003 Chevy Cavalier is right on 14V.

I don't know what they are using for nominal charge voltage anymore, but they may be playing around with dual rate to get faster recharge. I do know using higher than 14.5 (25C) is going to reduce battery life but they probably don't care. They may be compensating for an undersized alternator or whatever cheap thing they do to cut cost these days.

It is possible that the ECU reduces the VR (Battery voltage) setting after the engine has been running for a while. I should measure the voltage after the truck has been driven for a couple of hours.

AtomSoft · 7th October 2009, 01:44 AM

Sorry for delay heh: (THIS INFO IS ON BOX)

Code:

APPLICATION--------------CHARGING VOLTAGE---------MAX INITIAL CURRENT
Normal Charge -------------      14.4-15.0v        ---------               2.1A
Standby/Trickle ---------------      13.5-13.8v        ---------               2.1A

Better View:

NORMAL CHARGE:
VOLTAGE =  14.4-15.0v 
MAX INITIAL CURRENT =  2.1A


STANDBY/TRICKLE CHARGE:
VOLTAGE =  13.5-13.8v 
MAX INITIAL CURRENT = 2.1A

audioguru · 7th October 2009, 03:26 AM

RadioShack never had brand new goods. They sold factory rejects (seconds) and defective parts.
Those batteries are probably cheap Chinese ones and spent a few years on a boat then a few more years in the store. They are dead and probably will never work properly because an old lead-acid battery does not work anymore.

bountyhunter · 7th October 2009, 03:33 AM

Quote:

Originally Posted by MikeMl

It is possible that the ECU reduces the VR (Battery voltage) setting after the engine has been running for a while. I should measure the voltage after the truck has been driven for a couple of hours.

I just combed through the electrical section my official factory Chevrolet Service Manuals for the Cavalier and the battery voltage they list as "typical data value" are 13.9V. Volume 2, 6-707: BCM, IPC, and PCM all list 13.9V for battery voltage read by scan tool. However, the fault detector doesn't store a fault code until system voltage passes above 16V.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar
Title	Starter	Forum	Replies	Latest
Lead-acid battery charger	taz128	Electronic Projects Design/Ideas/Reviews	21	11th August 2009 01:29 PM
Noob lead acid batt. charge controler ic	Goatnutz	Electronic Projects Design/Ideas/Reviews	13	10th July 2009 01:51 PM
Lead-Acid battery reverse polarity charge	Daniek	General Electronics Chat	31	5th June 2009 01:31 AM
EASY- Charge Sealed lead acid battery with benchtop power supply	spitso	General Electronics Chat	4	22nd May 2009 09:02 PM
Lead Acid Battery	dimper129	General Electronics Chat	3	18th September 2007 10:23 AM

6th October 2009, 01:45 AM	#17
Sceadwian	The stupidest simply method to charge a lead acid cell is the same method a car does. When the engine is running it outputs 13.8VDC. Attach a 13.8VDC regulated supply when not in use and you're all set. You can get more complicated, but it's primarily for more deeply discharged batteries. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har." Last edited by Sceadwian; 6th October 2009 at 01:47 AM.

6th October 2009, 01:52 AM	#19
Sceadwian	Why 14.4v? Doesn't that cause excessive gassing of the battery? __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."

6th October 2009, 02:50 PM	#24
AtomSoft	please remember these are not car batteries so there is a difference. I will post what i have later on today after work __________________ 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

7th October 2009, 01:44 AM	#28
AtomSoft	Sorry for delay heh: (THIS INFO IS ON BOX) Code: APPLICATION--------------CHARGING VOLTAGE---------MAX INITIAL CURRENT Normal Charge ------------- 14.4-15.0v --------- 2.1A Standby/Trickle --------------- 13.5-13.8v --------- 2.1A Better View: NORMAL CHARGE: VOLTAGE = 14.4-15.0v MAX INITIAL CURRENT = 2.1A STANDBY/TRICKLE CHARGE: VOLTAGE = 13.5-13.8v MAX INITIAL CURRENT = 2.1A __________________ 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 01:47 AM.

7th October 2009, 03:26 AM	#29
audioguru	RadioShack never had brand new goods. They sold factory rejects (seconds) and defective parts. Those batteries are probably cheap Chinese ones and spent a few years on a boat then a few more years in the store. They are dead and probably will never work properly because an old lead-acid battery does not work anymore. __________________ Uncle $crooge Last edited by audioguru; 7th October 2009 at 03:28 AM.