| T O P I C R E V I E W |
| random |
Posted - Nov 14 2009 : 11:55:03 AM
can this charger charge 1.2v batterys"s" hooked up in a certain way
if not how could i make it charge 1.2v batteries |
| 12 L A T E S T R E P L I E S (Newest First) |
| Aaron Cake |
Posted - Jan 09 2010 : 11:04:52 AM
Yeah, the TRIAC gets warm. I just bolted mine to the side of the metal case. Glad it worked out for you. |
| coastie |
Posted - Jan 06 2010 : 10:49:20 PM
Aaron,
I got the charger working. it's charging up my RV battery and working great.
When I first tried it I put in on my John Deere Diesel Gator but the battery was fully charged and I was confused.
The RV, I ran everything to drop the battery to 11.5 volts. It's at about 12.90 now so I am happy.
I got a small fan for the box I will put it in. Even with a heat sink that Triac gets pretty hot.
Thanks Coastie |
| coastie |
Posted - Jan 03 2010 : 7:29:42 PM
Hi Arron,
I have not built anything electronic for 25 years. So now retired and have the time. I built your 12v lead acid charger.
I have a 120/12v 4 amp stepdown transformer and without a load is about 14+ volts.
The dc output on the charger with the pot turned all the way up is 9.7 volts dc.
I used a BT169 scr for the BRX49 and a ECG5867 for the P600 diode. I had the T1 and T2 backwards on the triac and fixed that.
So what do you think I screwed up? I am thinking I need a 16v secondary transformer.
Otherwise I love your site and can't wait to get this charger going and try making something else.
Thanks, Coastie |
| Aaron Cake |
Posted - Dec 17 2009 : 09:45:12 AM
And remember, the more current you draw from a lead acid battery, the less power it has available. This is called the Peukert effect. This means that you need to oversize your batteries in order to make efficient use of your capacity. |
| audioguru |
Posted - Dec 14 2009 : 10:54:55 PM
[quote]Originally posted by jeffreywong
Which mean if i using a 20ah or lower ah battrey, that would not able to run my equipment with operation current of 25A?
Maybe, maybe not. It depends on the quality of the battery.
If a 20Ah battery works with an output of 25A then it might last only 20 minutes to 30 minutes or the battery might boil dry in 10 minutes. |
| jeffreywong |
Posted - Dec 14 2009 : 7:56:23 PM
Which mean if i using a 20ah or lower ah battrey, that would not able to run my equipment with operation current of 25A ?
Thanks... |
| audioguru |
Posted - Dec 14 2009 : 10:27:05 AM
A lead-acid battery rated at 26Ah can supply 2.6A for 10 hours, or 26A for 40 minutes, or 56A for 12 minutes, or 112A for 2 minutes, or 224A for a few seconds and might be able to supply 448A for 1 second. |
| boron |
Posted - Dec 14 2009 : 09:21:42 AM
Ah is a measure of the storage capacity of the battery. If you convert the units its the same thing as Coulombs or units of charge.
The easiest way to understand it is that this battery can supply 26 constant amps for a one hour period before it runs out of charge. So if I drew 52 amps it would last half and hour, if I drew 13 it would last two hours, etc. |
| jeffreywong |
Posted - Dec 14 2009 : 07:51:58 AM
just need to be confirm
1)
Download Attachment:  battery charger.zip
15.13 KB
Will this battery charger circuit charge my lead acid battery of 12V, 26ah ?
2) What mean by a battery of 26ah, izit this battery can supply maximum current up 26A only ?
3) If my equipment with operation current of 12A to 25A, can i use this 12V 26ah battery ?
4) If not, what you suggestion?
Thanks... |
| Aaron Cake |
Posted - Dec 13 2009 : 10:43:34 AM
Yes. The circuit doesn't care about the primary voltage of the transformer. It just cares about getting a pulsing DC signal after the rectifier a few volts higher then 12V.
Your battery is rated at 25 amp-hours, and most batteries like to be charged at fractions of their discharge current. Lead acid batteries will take a lot of abuse, and as long as you don't boil the battery and keep its temperature under control, you can charge it with as much current as it can handle. That's not really relevant here, since this circuit can't really beat current into the battery. Long story short, at around 3A, you are looking at around 6 hours. |
| jeffreywong |
Posted - Dec 11 2009 : 05:37:00 AM
1) For the 12V lead acid battery charger, can i use a 240V- 12V / 2A transformer instead of 120V transformer ?
2) Can i use this charger in my 12V 25A battery ?
3) If so, how long i need to charge it until full ?
Thanks... |
| audioguru |
Posted - Nov 14 2009 : 12:40:33 PM
The circuit is designed to charge a lead-acid battery type.
A 1.2V battery cell is not lead-acid, it is Ni-Cad or Ni-MH which are completely different and need their own charger circuit. |
