Replacing Power Converter

[Roam America]

I am about to order a new power converter and am wondering. Is there any advantage to replacing the existing [55A] converter with a higher rated converter? The one I am considering comes in 60A or 70A. Going with the 60A is a no brainer as it is the closest rating to what I have. But is there any advantage to spending $30 more for a 70A?

[jlyon69]

Originally Posted by K-Star

I am about to order a new power converter and am wondering. Is there any advantage to replacing the existing [55A] converter with a higher rated converter? The one I am considering comes in 60A or 70A. Going with the 60A is a no brainer as it is the closest rating to what I have. But is there any advantage to spending $30 more for a 70A?

Converters are placed in MHs based on the max draw of the batteries. In my case, I have little battery draw now. I have no inverter and dont need one. All my lights are LED now as is the 12v TVs.

My coach came with a 50amp converter, there was an option for an inverter but, didn't come in my coach. I just got a 45amp PD 9200 converter and I have never known the cooling fan to ever come on.

So unless you're going to upgrade your inverter by 1000 watts or so, the 60 is fine and I see no benefit in the 70, unless of course you plan to ADD a 2500 watt inverter.

[garym114]

It depends on how many batteries you are charging with the converter. Deep cycle and golf cart batteries have a max charging rate. Charging two 220 ah 6v batteries in series at a 70 amp rate exceeds the max charging rate.

[Roam America]

I have 2 batteries (1 house battery and 1 for starting the generator). I'll have to take a look tomorrow to see what amperage they are.

Is there s formula to determine what size converter is required to charge 2 batteries of a given amperage?

[John Hilley]

The converter doesn't push a 70 amp charge in to the battery. The charging rate may not be any different between the 50 amp converter and a 70 amp converter, if the converter has the capacity to provide 12 VDC to lights and appliances and charge at the same time. With one battery it doesn't make much difference and not much at al if you don't run your batteries low.

[Dave78Chief]

The basic rule of thumb for maximum charge rate is 25% of battery capacity in amp hours. So, a 200 AH battery can safely accept a maximum of 50 amps charging capacity. However, I believe the newer smart converter/chargers also test the battery to ensure they are not putting out to much current. Some Inverter/chargers are adjustable. Additionally, one must also account for additional loads being provided by the converter/charger. If you are supporting 15 amps of loads (lights, fridge, inverter, etc.) then a 60 amp charger can only provide 45 amps of charge capacity at that 15 amp load value. If you plan on upgrading your battey bank size, then you want to account for that in your converter selection. A 3 stage converter only provides max amp charge rate in the bulk stage. Once the set voltage is reached (14.4 for a PD9200 series), then the voltage is held constant at 13.6 and the amperage rate is tapered off until the battery is completly charged (absorbtion stage). Asorbtion stage operation is basically the same as a car alternator system except the voltage is a tad lower in order to reduce the loss of house battery water.
Converter and Battery bank size selection is driven by what your lifestyle is, how many DC loads do you have and the size battery bank you have. If you always are at a campsite with shore power available then a smaller unit is OK. Lot's of boondocking means you need the fast recovery of a larger converter. Boondocking also means the need for more battery capacity (more AH's). Large number of DC loads also drives the need for more battery capacity and charging capability.

Dave

[Roam America]

Thanks for all of the input. I found a PD-9270 on E-Bay (new) for $ 178 so I ordered it.

[John Hilley]

Good choice and a good price. You will be happy with it.