MightyMax 18Ah AGM battery

[sternwake]

I got a reply from mightmax battery and they said use the same specs as for the UB12180

http://files.upgi.com:8086/UPGFileServic...heet/D5745

5.4 amps or smaller charge current?!!!! Unlikely.

Turns out they sell 20th 20 and 22 AH batteries in this same exact size casing, but they do weigh more.

The UB12200 and the UB12220 for those wanting a bit more capacity in the same size package. One of Amazons search hits for the 2Ah version even says it is for a schumacher jumper pack.

I powered my laptop for an hour last night with it and then set the 40 amp meanwell loose on it at 14.9v.

Amps this time did taper to 0.09.

I tested my wattmeter's, and my Clampmeter's accuracy against a Extech multimeter. The Clampmeter is surprisingly accurate reading almost exactly in line with the extech rom 0.01 amps upto at least 6 amps.

The one portable wattmeters draw is measuring 0.02 amps, but on first powering up it will touch upon 0.03 a few times. So I suspect its parasitic draw is 0.0255 amps and gets rounded up on first power up when it draws a bit more to fire up the backlight.

The portable wattmeter seems to consistently read 0.1 amps low, at any amperage under 2 amps, but is dead nuts accurate with the other two ammeters above 2 amps.

I have been trying to figure out how I am going to wire this up to the automotive post clamps in my engine compartment AND be able to quickly remove it with minimal amount of fussing with tools and jumpstart someone else with some 8awg alligator clips with 45 amp Anderson powerpoles attached on one end.

I recall this youtube video where the guy tested the 45 amp andersons until failure with a 500 amp carbon pile tester, and they wound up passing over 340 amps for several seconds before the plastic housings and the 10 gauge wire insulation melted, the actual contacts inside appeared to remain intact and bonded.

This is far more than the 140 amps of the usual starter motor. My starter motor is actually rated at 1.4KW which at 12v is 116.7 amps and 140 amps at 10 volts.

So i think I am going to splice more 8awg into the existing 8AWG and use parallel 45 amp anderson powerpoles as each should be fine passing 70 amps for a few seconds if this battery alone by itself is to start my engine. Thw wattmeters being rated at 130 amps, surge, should also allow me to hook 2 inline and record the Max amps, minimum voltage, and Watt hours and amp hours. I pass 40 amps continuous through these wattmeters for 30 minutes so a few seconds of 70 to 80 amps should be well withint their mimits too.

Now to go check how many 45 amp andersons I have available.