Ordered new AGM battery ....???

[grandpa pete]

Theese go out to all of you who think there is no such thing as a dumb question.....

What is the easiest way to tell if my new AGM battery is fully charged when I get it ?
Is it as simple as testing for 12.?? volts with a volt ohm meter ???

How many watts does my inverter have to be to run a 700 watt microwave ( hot dogs and popcorn :shy: ) ?

 

[tx2sturgis]

It's usually safe to assume that any brand new lead acid battery is partially discharged. Put it on a decent smart charger for awhile, some have an indicator light, and then you can be pretty sure its charged...or very nearly charged, good enough to put into service. 

As far as the microwave, the 700 watt rating is the power going into the food, but the power from the wall socket or inverter will be on a label on the back...

Its probably around 1200 watts, give or take, and a 1500 watt inverter might run it, but an 1800 or 2000 watt inverter surely will, assuming of course, the batteries and the cabling are up to the job.

 

[John61CT]

Volts don't usually give good SoC, not accurately.

Measuring amps charging current, keep volts up at 14.4 (or high end of mfg spec), watch them drop until under 1A.

That is 100% full. Let the battery rest for 48 hours, no load no charge, measure voltage and that is a benchmark of sorts.

Balmar SmartGauge is a good, easy to use SoC monitor.

Note both popcorn and hot dogs cook really well over butane or propane too, even a little backpacker's foldup unit.

 

[Trebor English]

What is the easiest way to tell if my new AGM battery is fully charged when I get it ?

Presume that it is not fully charged.  It will have been self-discharging since it was manufactured.

 

[John61CT]

Good retailers make sure they periodically get topped up while on the shelf.

But better to just buy ones with recent mfg dates.