The 800 watt espresso maker basically destroyed the battery. The visible leakage is proof of the damage. It is shot. The difference of the voltage reading is a combination of wiring issues and a battery that is absorbing more than the wiring or relay can deliver. It is not holding charge. 14.4 volts charging voltage is too high for an extended period. 2.35/volts per cell, current drops, have to taper down on AGM's. 2.2 to 2.25 max float. Dennis -----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Geza Polony Sent: Sunday, July 29, 2007 7:12 PM To: vanagon@GERRY.VANAGON.COM Subject: Re: Deep Cycle Batteries I've been using an Optima Yellow Top for the past year or so as aux battery and have always been surprised at how little reserve current it has. This is based more on intuition than anything else. (It seems like it ought to run an 800-watt 120 v espresso maker for 5 minutes, but no way...) But I've just been testing it with a meter and find that the refrigerator draws it down from a starting voltage of 12.30 to 11.99 in 20 minutes, to 11.84 in 60 minutes. Is that typical? Also, when the alternator is charging, it shows 13.9 to 14.4 at the cigarette lighter (vehicle battery) but only a max of 13.7 on the aux battery. Why wouldn't they be the same? The standard relay seems to be isolating them as it should. No, the Optima isn't sealed! There's white powder all over the ground post and you can see where liquid's been running out, probably eating holes in the floor. |
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