adulbrich 5,000+ posts
Olive oil un-virginer
Batteries are for reserve power, yes, but another member who's no longer active and I have had similar experiences with batteries. Here's what I've found:
When adding batteries, max charging voltage decreases. For example, with one battery in the bank I charged at 15.2v cold and 15.0v hot. With five batteries in the bank I charged at 15.0v cold and 14.7 hot. With 30 batteries, I charge at 14.7v cold and 14.5v hot.
Also, batteries hold what is called a "static charge". From my understanding, it's a bit more voltage than what the battery rests at after being loaded down. "12v" batteries for cars normally rest around 12.6v at a full charge. For those of you with volt meters installed in your vehicle, you may notice that your batteries retain a higher voltage even after you turn your vehicle off. Slowly, the voltage drops to where they normally rest due to internal discharging or the loads on the batteries like a headunit retaining memory.
When adding more batteries, I've experienced something I'd describe as "capacitance" above the resting voltage. Batteries have a little extra power to give to amps above what they normally rest at. I've heard people say "adding batteries only helps you maintain power at battery voltage". This is implying that batteries are only really supplying current to meet demand when voltage drops somewhere below 13v. I disagree with this. I think batteries can help maintain a higher voltage.
Working at a battery shop, I charge and load test batteries on a daily basis. I've learned a lot. Normally if a battery comes in and the person says" they had to jump it to get it here, it's been having trouble starting, blah blah blah" (typical story) I load test the battery and if it load tests bad we replace it. At the shop, we have a warranty of one year for free replacement. Also, there is a "5 year prorated warranty" where we'll offer a discount on a replacement if it goes bad after the first year. Sometimes, a bad battery can briefly test good after a vehicle has charged it and just been turned off. After knocking the "static charge" off, you can take a better look at the condition of the battery. Also, after putting a trash battery on a charger and pumping it with 200 amps of current, you can make it temporarily hold a high voltage and even load test decently one time.
The more batteries I add, even with more current demand, I find that maximum system voltage is lower, but I also have less drop. Lowest I've seen so far with the new bank is 13.9v. That's with three 7k's wired to .35 nominal. With the TFE wired at .5, the same alternators, and just five batteries, I was in the low 13's going full tilt and had previously dipped into the high 12's. Nobody can tell me that the batteries weren't helping maintain that higher voltage. I've got the same alternator power, but more current demand and am having less voltage drop.
Just my two cents on electrical theory stuff. Has anybody else had similar experiences or even opposite opinions?
When adding batteries, max charging voltage decreases. For example, with one battery in the bank I charged at 15.2v cold and 15.0v hot. With five batteries in the bank I charged at 15.0v cold and 14.7 hot. With 30 batteries, I charge at 14.7v cold and 14.5v hot.
Also, batteries hold what is called a "static charge". From my understanding, it's a bit more voltage than what the battery rests at after being loaded down. "12v" batteries for cars normally rest around 12.6v at a full charge. For those of you with volt meters installed in your vehicle, you may notice that your batteries retain a higher voltage even after you turn your vehicle off. Slowly, the voltage drops to where they normally rest due to internal discharging or the loads on the batteries like a headunit retaining memory.
When adding more batteries, I've experienced something I'd describe as "capacitance" above the resting voltage. Batteries have a little extra power to give to amps above what they normally rest at. I've heard people say "adding batteries only helps you maintain power at battery voltage". This is implying that batteries are only really supplying current to meet demand when voltage drops somewhere below 13v. I disagree with this. I think batteries can help maintain a higher voltage.
Working at a battery shop, I charge and load test batteries on a daily basis. I've learned a lot. Normally if a battery comes in and the person says" they had to jump it to get it here, it's been having trouble starting, blah blah blah" (typical story) I load test the battery and if it load tests bad we replace it. At the shop, we have a warranty of one year for free replacement. Also, there is a "5 year prorated warranty" where we'll offer a discount on a replacement if it goes bad after the first year. Sometimes, a bad battery can briefly test good after a vehicle has charged it and just been turned off. After knocking the "static charge" off, you can take a better look at the condition of the battery. Also, after putting a trash battery on a charger and pumping it with 200 amps of current, you can make it temporarily hold a high voltage and even load test decently one time.
The more batteries I add, even with more current demand, I find that maximum system voltage is lower, but I also have less drop. Lowest I've seen so far with the new bank is 13.9v. That's with three 7k's wired to .35 nominal. With the TFE wired at .5, the same alternators, and just five batteries, I was in the low 13's going full tilt and had previously dipped into the high 12's. Nobody can tell me that the batteries weren't helping maintain that higher voltage. I've got the same alternator power, but more current demand and am having less voltage drop.
Just my two cents on electrical theory stuff. Has anybody else had similar experiences or even opposite opinions?
