Ampere/hour battery rating.

[Derlyn]

I understand that, lets say a 100A/H battery can supply 100 amps for 1 hour, or, 50 amps for 2 hrs etc.

Is the above rating for 50% dod or 30% dod or 100% dod ?

Cannot seem to find this info anywhere.

[Isetech]

I understand that, lets say a 100A/H battery can supply 100 amps for 1 hour, or, 50 amps for 2 hrs etc.

Is the above rating for 50% dod or 30% dod or 100% dod ?

Cannot seem to find this info anywhere.

The DoD will determine how fast you destroy the battery, that is why it is so important to understand the C rate of the battery.

IF you discharge a lead acid battery at 1 C to 100 % DoD, chances are it will becomes a door stop in 5 cycles (added the cycles just to confuse you even more)

the life span cycles of a battery is determined by the

C rating and the DoD (depth of discharge)

Old lead acid batteries used hi cycle and deep cycle as a means to select batteries for applications.

Hi cycle for starting cars etc.

Deep cycle to use for camping, trolling motors on boats etc (they had thicker lead cells and a thicker base so you could put them direct on the concrete) That is how I understood it.

Lithium batteries are very different, and it is important to understand what makes a good lithium battery. Hence all the threads and questions, trying to make sense of it all throw the mine field of bullshit in features to make one battery look better than the others.

[Derlyn]

Let me re phrase the question.

For how many hrs can one draw 10 amps from a fully charged 100ah battery before 50% dod is reached ?

[Isetech]

Let me re phrase the question.

For how many hrs can one draw 10 amps from a fully charged 100ah battery before 50% dod is reached ?

A good question, it depends of the type of battery.


In "theory" it would take 5 hours.

[Derlyn]

Ok.

So if one doesn't want to discharge a battery past a 30% dod, then you will require a 100ah battery to get a usefull 30ah.

That's what I needed to know.

[Isetech]

The SOC is the state of charge

The DOD is the depth of discharge

If your SOC is 20 % then your DOD is 80%

IF means your battery only has 20 amp/hr left in the 100 amp/hr battery.

[Derlyn]

Understand.

They sell you a 100ah battery but you've only got 30ah if you dont want to exceed a 30% dod or 70% soc(take your pick ) and destroy it quickly.

Now I can start doing realistic calculations without sucking anything out my thumb.

[Isetech]

Understand.

They sell you a 100ah battery but you've only got 30ah if you dont want to exceed a 30% dod or 70% soc(take your pick ) and destroy it quickly.

Now I can start doing realistic calculations without sucking anything out my thumb.

That is why blowing R10-15 k on a 3.6 kva with 2 x gel batteries is a joke. You lucky to get 4 hours with a 400watts of the 36000watts. I never set the cut out lower than 11.5 V.

People get desperate with these ridiculous load shedding stages and hammer the batteries to try keep the lights on, which results in a decline in life cycle to a couple of months. I have batteries on my work bench that are not even 2 years old and cant hold a charge longer than 15 minutes.

[Isetech]

By the way, dont forget to throw in the peukert effect when you do your calculation once you start loading the battery (high discharge rate)

At least we can look forward to the new plan to start a "second" Eskom

[Derlyn]

No high discharge rate this side, brother. Maximum peak about 2 amps output. Less than 1amp 80% of the time.

I'm gonna double those currents for the calculations. Don't wanna discharge more than 30% so I'll be needing maningi batteries