Aaron's Homepage Forum
Aaron's Homepage Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
 All Forums
 Electronics
 Power Supply
 car battery charger

Note: You must be registered in order to post a reply.
To register, click here. Registration is FREE!

Screensize:
UserName:
Password:
Format Mode:
Format: BoldItalicizedUnderlineStrikethrough Align LeftCenteredAlign Right Horizontal Rule Insert HyperlinkInsert EmailInsert Image Insert CodeInsert QuoteInsert List
   
Message:

* HTML is OFF
* Forum Code is ON
Smilies
Smile [:)] Big Smile [:D] Cool [8D] Blush [:I]
Tongue [:P] Evil [):] Wink [;)] Clown [:o)]
Black Eye [B)] Eight Ball [8] Frown [:(] Shy [8)]
Shocked [:0] Angry [:(!] Dead [xx(] Sleepy [|)]
Kisses [:X] Approve [^] Disapprove [V] Question [?]

   Insert an Image File (GIF, JPG, JPEG, BMP, ZIP, PNG)
   

T O P I C    R E V I E W
varghese mp Posted - Sep 05 2013 : 08:14:38 AM
i have a smps power supply 24 v 3 amps
can i modify this to charge my car battery 12 v 70 amph
by connecting 2 similar value hi watt resistors across 24 v out put
and tap the 12 v across one resistor to charge battery. if possible what value should be the resistors.

thanks
varghese mp
2   L A T E S T    R E P L I E S    (Newest First)
pebe Posted - Sep 06 2013 : 05:11:59 AM
The most efficient, and probably the cheapest, method is to use a buck converter. This one you can set for 13.8V output and set up at to 3A charging current.

http://www.ebay.co.uk/itm/LED-Display-1-25-50V-DC-Adjustable-Buck-Boost-CC-CV-converter-module-/150975170731?pt=Travel_Adapters_Converters&hash=item2326d248ab
audioguru Posted - Sep 05 2013 : 9:25:47 PM
Two series resistors will waste a lot of power. If they have the same value then they make 12V with no load and make maybe only 9V or less with a load.
But a 12V lead-acid battery is dead when it measures only 12V, it is fully charged at about 13.8V.

You need a supply that is about 15V at about 15A and a battery charger circuit that limits the current and limits the voltage, detects a full charge then turns off or switches to a trickle-charge.

Aaron's Homepage Forum © 1995-2020 AARONCAKE.NET Go To Top Of Page
This page was generated in 0.03 seconds. Snitz Forums 2000