Battery ? Universal & Odyssey battery bank

[markz2004]

[crazyvwvanman]

It could and possibly even should be done, depending on where the battery is located. You just need a relay in that separate charging cable so the battery is not connected during starting. This will take some of the load off the wiring from the alternator to the main battery and would likely raise the overall charging efficacy of the whole configuration.

Mark

[Californio]

OK, but the question I have is, in practice, will the alternator/wires/relay combination put out enough voltage at the battery to charge it effectively? This is especially true of the Odyssey. And especially true if you're driving along with the fridge, headlights, AC, front fan, DVD player, stereo, radiator fan, personal cooling device, laptop charger, lava lamp, and all the other stuff drawing off that 90-amp alternator. I have doubts. However you hook it up, there is only a certain amount of current that alternator puts out, and if you run it close to capacity for eight hours in hot weather, you risk frying the poor thing.

Can anyone estimate the total number of amps that charging five batteries plus MAXIMUM summer usage would draw?

[PDXWesty]

[Californio]

Yes, hard to do without that lava lamp.

I guess what I'm asking is, worst case scenario, with all that stuff running, will charging a bunch of batteries overload the stock alternator? Mine works fine so far too, but I haven't tried it with heavy accessory usage and deeply discharged batteries yet, either.

[1621]

[Californio]

That's what I had in mind originally. You can get a 120 amp alternator for about $135 and go way up from there if you have the space. But typically the higher output alternators are also physically larger, and I'm kind of stuck there as my alternator is already hitting the deck lid (Tiico conversion with A-3 bracket.) So I'm up in the air as to cutting the deck lid open or leaving it with the 90 amp stock alternator. Which is in turn why I was asking about the maximum draw on the alternator. The 120 amp alternators are about 1/2 inch larger in diameter than the 90's.

[crazyvwvanman]

You began this part of the thread when you justified your need for a larger alternator by using improper voltage measurement data. Why not take PROPER measurements now and then use that to justify it? You must measure at the ALTERNATOR to find out if the alternator is unable to keep up with the load. Then measure also at the batteries to see if the charging wiring can keep up with the load. Putting in a larger alternator won't necessarily do ANYTHING to raise the charging voltage. Doing proper measurements will help you know what if anything you need to do. SyncroSimons setup shows a 90 amp alternator carrying a pretty heavy load, 100 amps.

It is not that hard to take a few measurements and then make modifications based on meaningful facts. Your wiring may need changes, your alternator may have an internal problem or the voltage regulator may be faulty or set too low. If you actually determine that the alternator is just too small, then get a bigger one.

Mark