Battery Usage

[ProAsm]

I wonder if any one has measured how long their battery actually lasts under load.
I have a fairly new Exide 102 AH Silver Calcium battery which uses a Noco Genius intelligent charger.
Yesterday we ran several lights plus the TV and for 3.5 hours before the Inverter switched off as the fully charged battery had dropped to 10 volts.
Working it out we used 170 watts which amounts to 170 / 12 = 14 amps off the battery and it lasted 3.5 hours which gives the battery a 50% efficiency rate which I suppose is acceptable.

 

[thehuman]

Running inverter till bat 10v not good for battery need more bateries

 

[The_Traveller]

Running inverter till bat 10v not good for battery need more bateries

Yeah isn't 10v about 80-90% discharge?

 

[dunkyd]

My two x 102's went to 12.5 after 4 hours. Think that's ok?

 

[The_Traveller]

My two x 102's went to 12.5 after 4 hours. Think that's ok?

That's just fine.

My batteries are good up to ( or down to ) 10.5v

 

[ProAsm]

Yes I realise it's not good to run till it dies but I was curious as to how long it would take before the inverter switches off.
Now I know so yes, a second battery is called for, although for the standard 2 hour load shed it would be ok as is.

 

[greg_SA]

10V seems pretty low for your your calculated 50% DOD...

 

[savage]

http://solarpowerplanetearth.com/solarsystembatteries.html

 

[ProAsm]

http://solarpowerplanetearth.com/solarsystembatteries.html

An excellent and very useful article savage