Community Forums

Frogman · 09-24-2017, 08:28 PM

2004 Allegro Bay 37db. When dry camping, the onboard batteries loose their charge after 2 1/2 days. Starting engine does not give deep charge as does the generator. My thoughts are to install an 80 amp charger in one of the storage compartments and permanently hook up the positive and negative charge leads to the batteries. There is a 110 plug-in in the storage compartment so when I need to charge up the batteries with a good deep charge, I can turn on the generator and plug in the charger for a faster and deeper charge.
Does this sound like a workable idea and has anyone ever done this kind of setup? Thanks for responding. Enjoy the day!

aether_one · 09-24-2017, 08:31 PM

Why do you think this standalone charger will charge the batteries any better than your built-in converter?

keymastr · 09-24-2017, 08:44 PM

Why not just upgrade the converter to one with a 4 stage charger like the Progressive Industries converters have? Yes, your plan will work also if you disable the charger on your converter so they are not both charging at the same time.

I am just now planning out a similar upgrade since the chargers in most RVs only charge the batteries to 80% and rarely have enough amps to desulphate the batteries. A good charger will extend the life of your batteries by at least 50% and probably nearly double as well as having more amp hours available.

Frogman · 09-24-2017, 09:05 PM

Because converter and generator are too slow to charge when engine or generator is running to get a good deep charge. A battery would charge faster with 15 minutes of generator run time I would tend to believe. You?

aether_one · 09-25-2017, 11:27 AM

Quote:

Originally Posted by Frogman

Because converter and generator are too slow to charge when engine or generator is running to get a good deep charge. A battery would charge faster with 15 minutes of generator run time I would tend to believe. You?

You know it is the converter that charges your batteries when your generator is running? I would think your Allegro would have a 75 Amp converter installed, but I may be wrong. Charging from the coach alternator should certainly be able to exceed 80 Amps.

And I don't know where keymaster gets his information that "the chargers in most RVs only charge the batteries to 80%", every RV I have owned has had a converter that would fully charge the house batteries, even the little WFCO 35 Amp 3 stage chargers. The problem most RVs have is overcharging the batteries and "boiling" them dry.

Crasher · 09-25-2017, 12:21 PM

What is the total amperage of your battery bank and how far are you draining them down to in 2 1/2 days? What is the amperage of your inverter? A 15 minute charge with 80 amps will only put 20 amps back into your bank. If you have four batteries, I'm guessing you have 420 total amps available when fully charged. Taking them down to the recommended 50% or 12.1 volts would require replacing 210 amps. It would take an 80 amp charger 2.6 hours to replace those amps if it could just charge a continuous 80 amps. The problem is it won't do that. Your inverter/charger is probably a three stage "smart" charger. To get a full charge back into deep cycle batteries requires close to 15 volts initially for bulk and gradually reducing voltage and amperage as the batteries get close to full.

When my six batteries (900 amps) are down to 50% or 12.1 volts, the generator starts and initially charges with 130 amps and will eventually be down to 10-15 amps and will take a few hours to get to full charge.

Edit: FWIW, the engine alternator can not get a deep cycle battery to full charge. A deep cycle requires the 14.8-15.2 volts of a smart charger to get fully charged. Most engine alternators will get to 14 volts at first, but the regulator brings the charge back to 13.6 volts. Not enough for a deep cycle battery.

Old Scout · 09-25-2017, 12:28 PM

As a general statement--any "intelligent" 3-stage/4-stage inverter/charger would be better for your batteries than the best "dumb" charger. Not enough information here to assess how well you batteries and OEM charger are handling the load you are putting on them????

Frogman · 09-27-2017, 06:36 PM

MODEL NUMBER: RV1012ULHW

1000W PowerVerter RV Inverter/Charger with Hardwire Input/Output

This is what coach has installed with 2 6v deep cycle batteries

Frogman · 09-27-2017, 06:37 PM

MODEL NUMBER: RV1012ULHW

1000W PowerVerter RV Inverter/Charger with Hardwire Input/Output

Coach has this installed with 2 6v deep cycle batteries

Kiawah · 10-04-2017, 12:24 PM

That charger you have, is 55 amp already.

When you run your gas drive engine, the alternator produces 12vdc which charges your chassis and house batteries. Your alternator probably puts out in the neighborhood of up to 150ish amps.

When you run your generator, it produces 120vac. That 120vac runs your charger, which produces up to 55 amp dc, and is a multi-stage charger.

https://www.tripplite.com/shared/pro...RV1012ULHW.pdf

If you boondock alot, and want to speed up the battery charging process, then yes you can buy a standalone charger (and turn off your existing charger functions). I would however get something that is substantially stronger than your existing 55 amp, perhaps a 100 amp charger? My magnum inverter/charger puts out 100 amps.

http://www.defender.com/product.jsp?...968&id=1982827

However since you only have the single pair of 6v batteries, you should check to see what their recommended maximum charge rate is. In my case I have 3 pair (6 batteries in total), so they can absorb 100 amps easily.

You might want to consider upgrading your house battery bank as well with additional capacity. You also will need to potentially upgrade your battery cables that feed the inverter/charger, (or to a new charger), to handle whatever the maximum current is and include a fusible link.