Battery show low percentage at full charge

[tomreid]

I replaced my battery with a Duracell 12V deep cell battery and after fully charging it installed it into the trailer. The monitor in the bathroom showed it was only 13.6 percent. What is the deal? Fresh water, grey water and black water tanks are accurate but not battery level. Anyone else have this issue.

[BayouBiker]

The SeeLevel shows battery voltage not charge % so it is showing 13.6 V. I am guessing you have a solar charger providing that as the topping charge voltage which is good for an AGM, a tad high for a wet cell which prefers 13.2 to reduce water loss. Resting, the battery fully charged will show 12.8 V at 60-70F and 12.7 at 40 or so. Let me know if this makes sense.

[tomreid]

So the Seelevel shows the voltage not %. I get that now. Thanks for your help.

[OTRA15]

. . . and you should wait an hour or so, after you stop charging the battery, to measure the voltage.

FYI this Battery School is a good resource for learning more about RV batteries:

http://www.batteriesnorthwest.com/ba...cfm?TID=1#ANC1

The list of voltage levels is important to keep in mind . . . that you should not allow a regular wet cell battery go below 12.2 volts [50%], or you risk damaging it.

Your Airstream owner's manual should also have a decent write-up on the voltage monitor, and on general battery maintenance.

Happy New Year,

[albret]

13.6 IS NOT per cent charged. You are looking at the level of "V" in the batteries, not "% of charge". At 13.6V you are 100% charged. My solar panels keep my batteries fully charged between 13.4V and 13.6V. Hope this helps a little.

Power capacity is how much energy is stored in the battery. This power is often expressed in Watt-hours (the symbol Wh). A Watt-hour is the voltage (V) that the battery provides multiplied by how much current (Amps) the battery can provide for some amount of time (generally in hours). Voltage * Amps * hours = Wh.

[GammaDog]

To build on BB and OTRA’s replies, that meter reads the voltage currently in your “12 volt” system. It might show anything between 11.something and 14.something depending on many factors. It is only a “battery meter” when the voltage in the system is coming from the batteries and not a charge source. At 13.6 volts, yours was telling you that a charger was running, since your new Duracell won’t output voltage that high. It could be the converter (if you were plugged into shore power) or a solar charging system or even the charging lead from tour tow vehicle... but it wasn’t the battery.