Still trying to understand electricity.

[LizardLady'sLittleLife]

My little battery pack is 140 watts. It has a 12 volt plug-in that looks like a cigarette lighter outlet and an outlet that looks like one you would find in a house (to run "regular" appliances from). It's intended to be a jump starter/supplemental electricity unit.

I sort of understand that I can determine how many watts per hour something draws by multiplying amps by volts (12 volts). So I can figure out how long this battery pack would run my 12 volt fan that draws 36 watts (less than four hours). 

How do you do the calculations if you're going to use the regular house-style outlet for something? 

Also, I've read that you shouldn't allow a battery to get lower than 50 percent of its capacity. Do you need to keep the little jumpstarter batteries fifty percent full, like you do a plain battery? 

Thanks. The electrical stuff is ALL new to me, but I learn quickly. 

 

[LeeRevell]

Also, I've read that you shouldn't allow a battery to get lower than 50 percent of its capacity. Do you need to keep the little jumpstarter batteries fifty percent full, like you do a plain battery? 

Yes, the same rule applies, if you want battery longevity.  That battery is just a small version of our bigger batteries.

 

[29chico]

LizardLadyMy little battery pack is 140 watts. It has a 12 volt plug-in that looks like a cigarette lighter outlet and an outlet that looks like one you would find in a house (to run "regular" appliances from). It's intended to be a jump starter/supplemental electricity unit.

I sort of understand that I can determine how many watts per hour something draws by multiplying amps by volts (12 volts). So I can figure out how long this battery pack would run my 12 volt fan that draws 36 watts (less than four hours). 

How do you do the calculations if you're going to use the regular house-style outlet for something? 

Also, I've read that you shouldn't allow a battery to get lower than 50 percent of its capacity. Do you need to keep the little jumpstarter batteries fifty percent full, like you do a plain battery? 

Thanks. The electrical stuff is ALL new to me, but I learn quickly. 

You will be better served by a deep cycle lead acid battery if you do not discharge it below 50% of it's amp hour capacity.  You do not want to keep a deep cycle lead acid battery at less than 100% charged for any longer than is reasonably practical. 

When a lead acid battery is left below fully charged for any period of time sulpher crystals build up on the lead plates of the battery.  The deeper the discharge and/or longer time of being in a discharged state the more sulpher is deposited.   Recharging a lead acid battery returns most of the freshly deposited sulpher into the sulfuric acid solution in the battery. But not all of the freshly deposited sulpher is removed every recharge.  This unremoved solid sulpher on the lead plates of the battery amounts to damage over time as it reduces the battery's capacity to store and release electricity.