Battery Charging Time - How Long?

Yep.......also depends how flat the batt is.....the charger may only be putting out 10A and your fridge might be pulling 7.5A so the charge time will be fairly long.. although the fridge should be cycling so 36hrs seems a bit long ??

If you really want to explore all the ramifacations of battery charging, I recommend this site:
http://www.windsun.com/Batteries/Battery_FAQ.htm#What%20is%20a%20Battery?

The projecta AC1500 is 15A RMS! The actual maximum output is 10A (10,000mA at 12v).

With a cut-in at 13.4v and a cut-out at 14.2v on the charger, it may not be fully charging the AGM battery......others may better answer that question.

Andrew

If your battery is fairly flat it will not absorb the rated current of a battery charger, particularly if it has a large rating compared to the battery size. As the charge level of the battery rises and may reach the current that the charger has set as the limit of the charger. This is referred to as the bulk charge. The bulk charge current most probably reach the limiting current of the charger but if the battery is a little sick it may not reach this limit.

When the battery terminal voltage reaches the maximum charge voltage set by the manufacturer, the charge current will start to reduce. This takes place at around 70% of the maximum charge level of the battery. The charging from this time on is referred to as the absorption charge. This is done with a reducing level of current to prevent excessive gassing in flooded batteries or the give the recombination process time to work in sealed batteries (if the recombination of the electrolyte does not take place the battery vents the gasses into the atmosphere and the battery looses water.) This process takes several hours - until the current reduces to an amp or two and the charger voltage is dropped automatically to the float voltage

Running a fridge at the same time reduces the current available for battery charging. There is nothing wrong with using the charger to run the fridge whilst charging the battery, but you have to make allowances for the extra time required to fully charge the battery. Also you must remember that the claims of quick battery charging times is often made by people who who are not really fully charging their battery.

Remember -you can not calculate the time required to charge a battery by saying a battery takes 20% more current to charge it than has been drawn from it, calculating the current required and then divide the result by the maximum rated current of the charger. Your battery may not be able to draw the maximum current over its bulk charge period and the last 30% may take a lot longer than the bulk charging time.

If you quoted your model number of your battery charger we also may have been able to give a little more information regarding times to you. There is also an interesting piece at the bottom of the page regarding the output current on this page of the Projector web site. Have a read and see if you can make sense of it.

PeterD

The ONLY way the charger can sense if the battery is fully charged is by detecting when the current drawn by the battery drops below a preset level.

Every time the compressor starts, the current increases so the charger assumes the battery is not charged.

hi i ran my Deep cycle battery pretty low also --- light in the Jayco were only a medium glow rather than the nice bright glow -- took almost 36 hours to fully recharge ( without any load on battery's - in my garage )

battery is only 2 months old


Boc