Heh.. I'd have expected nothing less of ya, Andy.. via the 0th Commandment:

12ish volts from Anywhere will do, if'n ya gots the time for it to trickle in...

(Actually anything up to 15ish source is fine. Above that on modern cars, -to save electronics- an internal regulator might dump to ground anything over about 15 V)

In fact, with Both sides of battery disconnected (!) you can use any old diode (5 amps is nice) capable of ~200V + suitable resistor for half-wave mod of Ohm's law - and your 120V. line!! in a real pinch. 2-3 amp diodes rated >1000V are tiny and real cheap. 5A may want a small jeat-sink.

I have heard... of people with mondo D-cells squirreled away, dumping a bunch into the 12 volt sump. A fresh Alkaline might get ~ 7? Amp-hours, say about half transferred in a reasonable time. 10 gets ya 15V. nom and you add new ones as these drop in voltage (where $ is beside the point).



Always feels good the beat the *System!



Ashton
* System: I have made an error and now the Gawds must punish me. :-(
Screw the Gawds: none is more powerful than Saint Ohm. :-)


PS - a lot of modrin cars do a lousy job of ever fully-recharging a battery, esp. in city, A/C, lights usage etc. The 15V clamp renders useless the High-sounding "current" rating of those now tiny alternators. You don't *get* real Ohm's law there.

I notice this on my (now modrin) car - via a quick Spec. Gravity test + noting actual nom. voltage value = under a small load to cancel out the fake-charge 'float' level.

Solution: a decent (sophisticated taper) charger. I think.. that periodic recharge to 'full' has the effect of delaying formation of those too-big crystals we call 'sulfation'. Anyway I try to toss the charger on every 7-10 days. My last battery went 104 months. Same battery in a friend's car, non-pampered, went ~ 70 months. 2 samples not very good stats.

Nice save!