help needed

Thread Starter

neet

Joined May 2, 2014
11
guys i need a little help.
i have a 24v sine wave inverter system which have 2 160ah 12v batteries.
from some days i noticed that inverter is taking much time to charge batteries after i tempered the amp pot.so i think i have to set the amps again.so how much amps batteries need to safe and quick charging??
 

wayneh

Joined Sep 9, 2010
17,498
An inverter is not a battery charger. ??
Do you have any other details about your system, such as block diagram, photo, or such?
 

wmodavis

Joined Oct 23, 2010
739
"..how much amps batteries need to safe and quick charging??"

You need to examine the battery manufacturer's specifications for the particular battery or battery chemistry you are using. They provide a safe range of charging currents that will maximize your battery's longevity.
 

MaxHeadRoom

Joined Jul 18, 2013
28,687
If these are Gel cell batteries, they often are charged using the float charge method, this is a fixed DC fixed voltage constant current equal to 2.25 to 2.5v/cell.
This is used in typical standby equipment.
If fast charging a fixed voltage at 13.8 for a 12v cell and the battery will regulate its own charge current by opposing the applied until approx 1ma charge.
Maybe your batteries are getting to the end of useful life if not charging as fast.
Max.
 

wmodavis

Joined Oct 23, 2010
739
Look for full technical specifications of your specific battery and/or manufacturers charging information and battery life vs charge-discharge cycles. Take into account your intended battery usage. It is probable there but up to you to find, digest & apply to your best advantage.
 

Thread Starter

neet

Joined May 2, 2014
11
batteries are 3 month old only.problem occured after tempering the amps pot of the inverter circuit
 

wmodavis

Joined Oct 23, 2010
739
"batteries are 3 month old only."

That is nice but to assure long and useful life you must be sure you follow the designers recommendations. Otherwise you will be replacing them often. If that is OK with you charge them any way you want.
 

wayneh

Joined Sep 9, 2010
17,498
OK, I'm beginning to understand your problem: This is all about a UPS. You tampered with the indicated pot and don't recall the original position. As a result, your batteries seem to take longer to charge than they used to.

You're seeking help in how to get it set back to where it was.

What led you to mess with that pot in the first place?
 

wayneh

Joined Sep 9, 2010
17,498
Oh dear.

Your observation that the battery charging takes longer - was this under normal operation, in which the batteries are merely being tended, not deeply discharged during an outage?

If you're lucky, that pot might be adjusting only the float voltage, which is something easy to measure. If it's adjusting the current level, it will be a bit more challenging.
 

Thread Starter

neet

Joined May 2, 2014
11
no problem with battery back up only taking too much time to fully charged or charging cut off.i have multimeter to measure volt and current but do't have any idea abt minimum charging amps needed for two batteries
 

Thread Starter

neet

Joined May 2, 2014
11
i found the inverter manual.....now wat the red marked value indicates? 9amps for normal mode....does it mean 9+9=18amps for two batteries??

 

wmodavis

Joined Oct 23, 2010
739
Measure the charging amps to the battery. What is it?
Measure the charging voltage to the battery. What is it?

Does that pot in the picture change the MAX charging amps or does it change the charging voltage?

Under "Battery Charging" in the Technical specifications it tells me the charging voltage should be between 13.6V for 'charging float voltage' up to 13.9V for 'charging boost voltage. What you set it to within that range depends on the service you want out of the batteries. Higher voltage will charge faster but give you potentially less overall battery life. Lower charging voltage will charge the batteries slower but potentially lengthen battery life. It's a trade off.

Need a bunch more info from you so if you can answer these questions it might help. Otherwise you should consult with the manufacturer of the Inverter on how to properly set that pot.
 
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