Help with House Battery

[highdesertranger]

trying to judge state of charge by voltage alone, is very inaccurate. but on AGM, Gel, or Sealed Lead Acid(SLA) you really don't have a choice. the battery must be resting for at least a few hours, the longer the better(overnight) to a point. but who can let their battery rest for that long. resting is no power going in or out of the battery.

I had to reread that chart that Wayne posted a few times. it's got to be a misprint. the last line says,

"Temperatures below 30 degrees Celsius (below Freezing) can reduce capacity by 30% or more."

hahaha 30° Celsius is way above freezing in fact 30°C is 86°F. freezing is 0°C. whoever made that chart needs to clean it up.

highdesertranger

 

[becida]

trying to judge state of charge by voltage alone,  is very inaccurate.  but on AGM,  Gel,  or Sealed Lead Acid(SLA)  you really don't have a choice.  the battery must be resting for at least a few hours,  the longer the better(overnight) to a point.  but who can let their battery rest for that long.  resting is no power going in or out of the battery.

My reality is voltage is the only practical day to day way to keep track of how much juice my batteries have in them. That voltage is being read while they are being used too.  It's the best I can do so that's what I use.

When the batts are at 12.2 I have to decide to either charge them, stop using them or accept that further discharge will lessen their life span.

 

[highdesertranger]

a battery monitor that counts amps in and amps out is far more accurate then the voltage. if it's set up correctly from the get go it's very accurate. highdesertranger

 

[wayne49]

HDR, delete the post then. I wouldn't want to tarnish my 11 point social score.

Strange though, it is a UK site, perhaps they got their numbers from a USA site and changed the units from F to C without converting the values.

Main point was that the SOC table was originally posted without clarifying the battery chemistry.