HOW LONG DOES YOUR HOUSE BATTERY HOLD A CHARGE

joey2cool · 01-29-2012, 08:35 PM

I know there are a number of factors involved, but I'm curious about the length of time your house battery(ies) can hold a charge with a minimal load on after fully charging them. To try to keep the playing field level, please include the following facts with your response (my answers are given for example):

1. Number and type of batteries (e.g., I have two 100 a-h Deka 27 AGM house batteries)

2. Known devices always on (e.g., I have a Charge Wizard directly connected to the batteries and on at all times - less than 0.05 amp-hr draw)

3. Average temperature for duration of test period (e.g., low 30 to 40 desgrees F)

4. The voltage you start with after fully charging (e.g., starting at 12.8V)

5. The age of your batteries (e.g., 1.6 years)

6. Given the above facts, list the number of days a full charge lasts and the ending voltage before recharging (e.g., 21 days at 12.5V)

**daveb** · 01-30-2012, 11:47 PM

I think the real test would be how most new batteries are tested, and that's against the 20 hour rule. I would have to test at night or disconnect my solar to do it and I don't really want to do that. At least you have a value to compare to. Maybe this will help.
http://www.instructables.com/id/AmpHourTest/?ALLSTEPS

OttoVolcomSMB · 01-31-2012, 04:13 AM

I wish I could tell you. I have the solar setup so I don't believe I would be able to find out. Curious though.

Carl · 01-31-2012, 05:25 AM

solar here as well

Ford_6L_E350 · 01-31-2012, 09:44 AM

I have two Group 27 AGM batteries. After a full day of driving (charging) they would hold above 11.5V while keeping my Norcold 12V Frig running and not much else on. Then I put a solar panel on the van and no more discharge like that.

Mike

Roonie · 01-31-2012, 12:13 PM

1. Number and type of batteries

I have 1 big Lifeline AGM 4D

2. Known devices always on

none

3. Average temperature for duration of test period

average around 40 degrees

4. The voltage you start with after fully charging

It starts with around 12.4V usually charged. When the engine is running it jumps to 14.1V

5. The age of your batteries

My battery is original to the build late 2006. So I am going on 6 years which is about the lifespan of this battery.

6. Given the above facts, list the number of days a full charge lasts and the ending voltage before recharging

After a week or so it drops to about 11.8V. After two weeks it drops to 11.5-11.4V. I don't let it go beyond 2 weeks without driving it somewhere or plugging it in. My onboard voltage indicator will read medium charged at this time.