What does this 100AH mean?

[hameeds01]

peukart equation battery

100AH @ 12v as mentioned on a battery, does it means that a battery is capable of providing 100amps of current for 1 hour at 12 volts?

 

[mister_rf]

No.
As the rate increases, the battery's capacity decreases, although its actual capacity tends to remain fairly constant.

Almost from Plante's invention of lead-acid batteries (in 1860), it has been observed that the true capacity of a battery is related to its rate of discharge (the faster the rate of discharge, the less of its nominal amp/hour capacity that can be delivered. The effect is a result of the battery's internal resistance which, in turn, is dependent on the battery's type and method of construction.

The phenomenon was extensively studied and quantified by a researcher named Peukert. In 1897, Peukart developed an equation that describes the effect. It is has subsequently been very thoroughly established that Peukart's law is accurate within +/- 0.5%-1.0%

See Peukert's Law

**broken link removed**
http://www.geocities.com/CapeCanaveral/lab/8679/battery.html
http://www.smartgauge.co.uk/calcs/peukert.xls
http://en.wikipedia.org/wiki/Peukert's_law

 

[ric_vas]

Below you will find lot of technical information about batteries:

**broken link removed**

Ric

 

[fsahmed]

In general it is the nominal power rating of the battery, indicating indeed that if u keep drawing 100A, it will die in one hour.. but this is just nominal and it can not be assumed that the battery would last for a half hour if u draw 200A from it

 

[mister_rf]

Not even close, for one 100Ah accu a discharge current of 1C=100A, will give you less then 30-40 minutes…
Usual in practice the nominal capacity is given for discharge at the 10-20 hour rate.
For a specific accumulator You need to check the producer datasheets.
See the chart
**broken link removed**

 

[season2]

ı am inexperienced too but to my opinon ıt may be given the sample below to understand the amper
assume that there is a water bottle on a table, and there are two person as a father and kid, let's say bottle is full of 2 lt of water, that means and equals to voltage. Father and his kid all have pipette plunged into bottle. They means and equals to two different appliances and has in two different consumer capacity. So, father may consume the water in one hour but kid in 2 hours. So, ıt can be said the first apliance's consumer capacity as bigger as a double of second appilance, each can use and consume the 2 lt (use same voltage) but consume in different duration. All bateries are limited with its chemical structer, and each appliances consume and need electiricity flow rate, and this means the amper rate

 

[ultrabrains]

Well the direct anser to if " 100AH @ 12v as mentioned on a battery, does it means that a battery is capable of providing 100amps of current for 1 hour at 12 volts? " is

YES

and that is simply when the battery is new. Over time when the battery is charged and discharged the AH rating starts to drop till you have to replace the battery.

The ratio of drop in AH is what others have been trying to explain, but the summary is that it drops based on increased continous use.

See it like this:

If a battery is rated for 100AH and you use 100A for 1hr the battery might not even last 9 months of every day use.

But if use a battery is rated for 100AH and you use 25A for 4hrs the battery will last 18 months of every day use.

 

[mister_rf]

No way... 8)
See some technical details about accumulators, how they rate capacity...
There's always a ''C10'' or ''C20'' when you check for capacity.

 

[shabab]

this may be best site www.batteryuniversity.com/index.htm