Yamaha ef2000 charging the batteries

Dalo wrote:
I started looking more closely at the Parallax 7355 and I see that it has a max output of 55 amps but a typical battery charge rate of only .5 amps.

Looks like somebody got the decimal point in the wrong place. That would be a charge rate for Float.

Dalo wrote:
The Yamaha genny has a 12 volt outlet that puts out 8 amps. Would this be a better way to charge my batteries directly from the generator?

No. That genset 12 vdc charging output is unregulated and can easily result in overcharging your batteries. Instead invest in a good stand alone charger, plug it into the genset, and charge with it. In my case, I simply turned off my crappy WFCO 8955 converter and instead use a CTEK Multi US 7002 to charge the trailer battery. In your case, because you're using a genset as your charging source, you'd be better off with a CTEK Multi US 25000 for much shorter genset runtime. NOCO also offers similar products.

The way to go if your converter is a single stage charger is to upgrade to a multi-stage as that will serve you much better than the DC charger contained on many generators. BestConverter.com is a good place to get info, Randy can walk you through the process.

You can get more amps from the 7355 than from the gen's DC charger, which does about 8 amps. Ignore that 0.5 amp thing which they explain is phoney.

The limitation of the 7355 is its voltage of 13.8 when you want 14.8 or at least 14.4. You should be getting anywhere from 35 to 25 amps at first from the 7355 depending on how far it is from the battery bank and the wire gauge they used.

The 7355 will do 55 amps when used as a power supply with good wiring for the amps. EG, run something from the inverter that draws 100 amps and turn on the 7355, and amps drawn will show as 45, indicating the converter is supplying the other 55.

But on a battery it can't do that because the battery voltage when being charged gets up close to the 7355's 13.8 so not enough voltage diff to make for high current. You need a charger that will run in the mid- 14s to make a wider spread between the two voltages and get the high current.

There are several choices for which converter or charger that would be. Each brand has its own fan club :)