High Amp Alt vs. Bigger Cap

**specialeditiongtp** · 03-16-2009

your batterie should always have 13.7-13.8 volts whether it is being charged or not. If you have a large load on your batterie for a long time and its not getting recharged, it will slowly lose voltage, not quickly jump down to 12 volts. If your batterie quickly drops to 12 volts when there is a load on it your batterie is junk!

**_nick_** · 03-18-2009

hmm.... I already know this but for reference wikipedia states:

Automotive starter batteries (usually of lead-acid type) provide a nominal 12-volt potential difference by connecting six galvanic cells in series. Each cell provides 2.1 volts for a total of 12.6 volt at full charge.

Car battery - Wikipedia, the free encyclopedia

A battery that holds more than 12.6 volts is just showing surface voltage, not a true output for any length of time. Its just the way she goes, batteries will not hold any more than 12.6 volts reliably.

**felonygtp** · 04-03-2009

An AGM battery is different than a wet cell if your putting wet cells in the trunk your asking for trouble. What you fail to mention is that your caps up to 2 farad only have the potential to hold as much as a 9 volt battery. There is no difference between a .5 farad and a 2 farad cap until the voltage is increased past 24 volts. A capacitor is a marketing gimmick always has been. Their used to make newbs feel like they did something to help there alternator when if fact they only hurt the performance of the electrical system. A surface charge on a wet cell still has more capacity than 10 2 farad caps. By adding a small yet efficient AGM battery you help stabilize voltage so the alternator can do its job if you add a large less efficient battery you will need a high output alternator.

**felonygtp** · 04-03-2009

Originally Posted by specialeditiongtp

your battery should always have 13.7-13.8 volts whether it is being charged or not. If you have a large load on your battery for a long time and its not getting recharged, it will slowly lose voltage, not quickly jump down to 12 volts. If your battery quickly drops to 12 volts when there is a load on it your battery is junk!

I believe this is in reference to your AGM battery not your wet cell. A deep cycle battery is alot different from the factory battery installed in the vehicle. A wet cell battery has a higher capacity and also higher internal resistance were as a deep cycle battery has a lower CA rating and a lower internal resistance. A deep cycle battery is not as good for starting a car but its better for your audio system. The reason your voltage is higher without a draw is because of the design of your battery, I don't want to explain the difference so just google it or read it at /www.realmofexcursion.com/forum/showthread.php?t=923 just a good place to read and make some of your own decisions whats best and why stuff works.