Battery vs genny questions
Hey all you electrically smarter than me people ... I need some battery help please. 9 days of dry camping. I'm bringing my genny but we're in a State Park, in the middle of 10 families with tents,...
Forum Discussion
Just do the 24 to 48-hour test that I suggested, and BFL also asked for, before you change anything. If you have a clamp-on meter for reading 12v, dc, amps and a meter to read dc volts, you can take readings every 2 to 4 hours to see how discharge is going on the battery
Also; once you start the generator you can watch to see if the voltage reading, taken at the battery-terminals will rise from initial voltage to 14.4 volts with-in about 10 minutes, or never rise above 13.7 volts.
You can check the amps with your clamp-ammeter (off either + or - cable) a minute or two after starting the generator. Depending on which cable you clamp over the reading could be + or - but it doesn't matter since you know you are charging.
Early on the reading might get into "bulk" mode with 20 or more amps before the voltage reads 14.4 volts. A weak battery bank will accept higher current initially with the need of 14.4 volts to force-feed the battery(s).
Whatever the amp reading is early on will drop with each succeeding hour of charging. The reading taken by a clamp-on meter at any given time represents how many amps would go to the battery if that rate existed over a full hour.
For example: reading at start of 20 amps, reading at end hour 1 of 10 amps. The average of the two readings would be 15 amps (15+10/2). The 15 amps (for first hour) would end up being lower due to battery charging not being 100% efficient.
As you can see unless you can get a higher amp reading thing are going to take time. Acid-lead batteries only accept around 20% of AH capacity on average (20 amps per hour for a 100 AH battery)to get to around 90% of full charge.
Also; once you start the generator you can watch to see if the voltage reading, taken at the battery-terminals will rise from initial voltage to 14.4 volts with-in about 10 minutes, or never rise above 13.7 volts.
You can check the amps with your clamp-ammeter (off either + or - cable) a minute or two after starting the generator. Depending on which cable you clamp over the reading could be + or - but it doesn't matter since you know you are charging.
Early on the reading might get into "bulk" mode with 20 or more amps before the voltage reads 14.4 volts. A weak battery bank will accept higher current initially with the need of 14.4 volts to force-feed the battery(s).
Whatever the amp reading is early on will drop with each succeeding hour of charging. The reading taken by a clamp-on meter at any given time represents how many amps would go to the battery if that rate existed over a full hour.
For example: reading at start of 20 amps, reading at end hour 1 of 10 amps. The average of the two readings would be 15 amps (15+10/2). The 15 amps (for first hour) would end up being lower due to battery charging not being 100% efficient.
As you can see unless you can get a higher amp reading thing are going to take time. Acid-lead batteries only accept around 20% of AH capacity on average (20 amps per hour for a 100 AH battery)to get to around 90% of full charge.
