lead acid battery charging

[dimper129]

hi all
I need a way to charge my lead acid battery automatically. the problem is this that the battery capasity is very large 12v 170ah. many IC,s are avalible for current and voltage regulation like lm317,lm340,lm350 or 78xx series but they are not capible to provide too much current. Is there any IC which can drovide too much current that i can charge my battery is six to seven hours.
OR is there any circuit which can solve my problem. i charge my battery with a simple transformer and rectifire which need very care that the battery should not over charge.

 

[RODALCO]

12 Volt charger

Best way is to get a normal transformer and bridge rectifier.

Match the TX voltage as close to the charging voltage of the battery, to minimise losses in series resistors etc.

A charging voltage to aim for is 14 Volts.
Allowe for 1.2 volts drop in the bridge rectifier, requires 15.2 volts dc.
A transformer with a 11 or 12 volts 20 Ampère winding is required.
Use a 35 Amp bridge rectifier on a heatsink.

Use a voltage comparator which switches a relay in the TX primary when the voltage reaches a predetermined value (14 volts) , and turn the charging cycle off.

Or go for a SMPS design which is more complicated.

Regards, Raymond

 

[stevez]

I am not the battery expert. The reading I have done suggests that the life and performance of a lead-acid battery can be optimized with a proper charging system. A "proper charging system" could get to be quite complex and the value of it is quite dependent on your needs, the cost of your battery, etc.

I backed my way into an understanding of the lead-acid battery on my RV. I purchased a SMPS convertor that will suppply up to 60 amps of current to run the RV systems or charge the battery. It also includes controls to keep the battery charged during periods of non-use (most of the time) as well as de-sulfate the battery. I am glad I purchased the system as it solved all the problems so the extra control of battery charging/maintaining was free to me. I cannot tell you if the extra frills (over a basic charger) are worth the extra cost.

If you do not have something to shut off your charger at some voltage level - or possibly a timer to put the circuit on trickle - then you might find just adding those features will be of significant value.

 

[ikalogic]

get a powerful power supply! lead acid batteries don't complain a lot about charging or discharging conditions..