A Forum run by Enthusiasts of MidNite Solar

General Category => General Discussion => Topic started by: Wxboy on April 12, 2012, 09:52:04 PM

Title: Battery life and DOD
Post by: Wxboy on April 12, 2012, 09:52:04 PM
What voltage do most people try to avoid going below in a 12 volt system to optimize battery life?  I've heard 50% SOC is a good target but I've seen different unloaded voltage #'s for 50% so I thought I would see what people on the forum recommend.  Right now I'm usually running 12.25v in the morning with no load other than the Classic before charging starts but I'm wondering if I can go lower and still be in the "safe zone".
Title: Re: Battery life and DOD
Post by: boB on April 12, 2012, 11:40:38 PM

A close voltage for 12V batteries would be around 11.8 volts, resting (little or no load).

That is also a good low voltage stopping point for a car battery resting voltage to make
sure that it will still start the car next time.

boB
Title: Re: Battery life and DOD
Post by: Halfcrazy on April 13, 2012, 05:42:21 AM
WXboy
The actual voltage for 50% would come from your battery manufacturer a close guess at 50% is 12.14vdc. Sounds like you are doing pretty good with the DOD.

Ryan
Title: Re: Battery life and DOD
Post by: niel on April 13, 2012, 12:02:25 PM
wxboy,
the actual at rest 50% dod figure for your battery is 12.18v as shown by the manual that i gave a link to in another response to you on charging voltages for your battery.

i might add that they make no mention of temperature compensation and you should temperature compensate with the battery temperature sensor even if taking a good guess at maybe a 4 mv per degree c per cell setting.
Title: Re: Battery life and DOD
Post by: phonetic on May 01, 2012, 03:12:00 AM
Telco power equipment I work on.  that uses 48volt battery bank, 44 volts is the low volts  battery disconnect setting..a battery discharged at 11 volts (12 volt nominal battery) is aprox 85% DOD under load.
No point sucking all the juce if it damages your battery bank for the extra 10% of charge.