Charge Current Questioin

Good ole WFCOs, at least they are known for their consistency !

otrfun wrote:
With no load on the battery, converter on (WFCO 8955), and battery discharged to 11.9 volts (I know, not recommended), I read 29 amps of current on the negative battery lead (hard to access the positive terminal). This dropped to 22 amps about 30 minutes later.

1. Can I assume this is charge current?

2. Typically what is the maximum charge current when charging at 13.6 volts?

Thanks!

1: YES

2: With that converter the maximum POSSIBLE charging current is 55 amps. However you will never see that due to loads present in the RV (Each amp the RV is eating is an amp that can't be used to charge the battery) .. Wire resistance (If the converter is a distance from the batteries) and internal battery resistance.

You might get close if the batteries are like 5 volts.. But please, Please do not run 'em down that far.

1. yes
2. that is typical for a single battery. And very typical of WFCO 3 stage converters to sit in normal mode even when the battery is very low.

If you want faster charging you will need a converter that will actually shift into boost mode. 13.6 volts is a slow charge. You need 14.2 to 14.6 volts to get a good 90%+ charge in ~3 hours.

It probably was at 14.4 for a little while, but depending on the size of the battery not very long. The WFCO's are kind of hard to get into bulk mode, and they don't stay there long - they try to stay at 13.6 for power supply to the house loads. They do vary the current depending on the state of charge of the battery, and 29 amps is fairly high for a single battery, if it is a wet cell battery. You want to stay below 20% of the 20hr AH rating, and 10% is better.

13.6 volts - Is that what you measured on the battery when you took the current readings? Where did you measure the voltage - on the battery, or at the converter?
I'd have expected the WFCO to start at 14.4 volts in "bulk" mode.

When charging the batteries keep in mind the batteries determine the charge current. It is up to you to have that much power available. If you have around 20AMPS per battery available to use this will re-charge your battery in as little as three hours time starting out with 14.4VDC...

I always start my recharge around the 11.9 - 12.0VDC charge state when camping off the power grid. Hopefully for us this is planned to happen around 8AM every morning when we are allowed to run our trailer off of the 2KW generator haha...

My three batteries in my battery bank will draw around 52 amps for 15 minutes or so when I hit them with 14.4VDc smart mode charging and then start dropping off as the batteries start taking on charge... After around two hours at 14.4VDC then it drops down to 13.6VDC and the total current is still around 6 AMPs or so for my three batteries for another hour of charging.

Roy Ken

Yes, you are measuring the charge current.
The maximum will depend on: rating of converter, size and type of battery, length of wire in between, size of wire in between, depth of discharge of the battery, etc.

Hi,

What size is the wire between the converter and the battery bank? What size in amp-hours is the bank?