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Post Info TOPIC: deep cycle batteries &inverters
T1 Terry


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RE: deep cycle batteries &inverters
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Peter_n_Margaret wrote:
T1 Terry wrote:
...... how many Ah can you draw from a 100Ah AGM battery under a 50 amp load before the voltage drops below 12v?

 Who cares? Not me and not anyone I know. Certainly not the OP. 

I do know I have been starting the OKA for over 7 years now from a single 120Ah/12V Fullriver AGM. That takes about 400A for up to 45 seconds in the winter. That is not relevant to any discussion here either.

Cheers,

Peter

 I would have thought it particularly relevant as the OP wishes to run an inverter from the AGM batteries. 50 amps is the draw required to power a 500w inverter under full load allowing for voltage drop that would be expected from an AGM battery. If a 100Ah AGM can't supply 50 amps without dropping below 12v then obviously the load would need to be split across more batteries. How long these batteries can maintain that load before dropping below 12v is also relevant as the OP needs to know how long the inverter can be run at full load.

I understand the inverter will run at 10v but now the load is 55 amps so the dead spiral starts once the voltage starts to sag, the current required goes up and the battery couldn't carry the load before so it will be even less likely to be able to carry an ever increasing load.

Surely you can see the relevance of this compared to the ability to supply 45 secs of energy to start a diesel engine, I doubt the OP is looking to run the inverter for 45 secs... As an aside, the initial draw may be 400 amps but I doubt it is continuous, what is the voltage while cranking?

 

T1 Terry



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oldtrack123


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T1 Terry wrote:

..... but then at a 10 amp load the LYP battery would deliver a lot more than 100Ah before it dropped below 12v so the comparison is still not on an even basis is it?

 

T1 Terry 

 And here we see the miracles starting again

"Much more than 100 Ahrs out of a 100 Ahr  LYP battery"noconfuse

Perhaps the makers should make the claim that their 100Ahr battery is in fact 100Ahrs plus xx amphrs capacity



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T1 Terry


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oldtrack123 wrote:
T1 Terry wrote:

..... but then at a 10 amp load the LYP battery would deliver a lot more than 100Ah before it dropped below 12v so the comparison is still not on an even basis is it?

 

T1 Terry 

 And here we see the miracles starting again

"Much more than 100 Ahrs out of a 100 Ahr  LYP battery"noconfuse

Perhaps the makers should make the claim that their 100Ahr battery is in fact 100Ahrs plus xx amphrs capacity

If only you understood the subject before you put your fingers on the keyboard Peter.

Lead acid batteries are rated at a 20hr discharge rate, the full capacity delivered over 20 hrs with an end voltage of around 10v or less while under load. For instance, a 100Ah battery discharged at a constant rate of 5 amps or a 0.05CA rate. If the same battery is discharged at a 100hr rate or a 1 amp load it will deliver more than 100Ah till the voltage drops below 10v under load. This is well understood by most battery people Peter.

LYP cells are rated at a 0.5CA rate or the full capacity delivered over a 2 hr period down to 3v per cell under load or 12v for a 4 cell in series battery. If the same 4 cell battery was discharged at a 5 amp rate rather than a 50 amp rate it will deliver more than the rated 100Ah capacity, just like a lead acid battery under a lighter load can deliver more than its rated capacity.

You really do need to understand the subject before you make critical statements Peter, it might regain you some credibility ;)

 

T1 Terry



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Cruising Cruze


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@Terry

No use trying to explain to him mate

Many good people left here because of that, He is always right

 

Cheers John



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T1 Terry


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Cruising Cruze wrote:

@Terry

No use trying to explain to him mate

Many good people left here because of that, He is always right

 

Cheers John

Not too sure about the last bit John :lol: I'm not interested in starting a slinging match but I thought it important to point out the problems with his argument/attack. I just felt if members better understand the facts the nonsense can simply be ignored so picking the wheat from the chaff became easier for all....... there is a lot of chaff out there wink

 

T1 Terry 



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Jaahn


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T1 Terry wrote:
....... there is a lot of chaff out there wink

T1 Terry 

 Hi smile

Never a truer word said !confuse

Jaahn



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Phil C


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Jaahn wrote:
T1 Terry wrote:
....... there is a lot of chaff out there wink

T1 Terry 

 Hi smile

Never a truer word said !confuse

Jaahn

 Pass no



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