Long charge time

[azrving]

First I want to thank Roy, Mex, Piano and others for posting good electrical info on here.
I have now installed a PD4655 converter, 4 new 6 volts, 6 gauge wire from converter to batteries and battery wiring is balanced.

Over the weekend I ran the batteries down to 12.1 and put it on charge at about 6:00 pm. It went into boost mode and I was reading 14.2 at the converter. I was reading 13.3 at the battery bank. I checked the converter as directed by PD tech and it has the ability to put out 14.42. I placed a temporary 4 gauge cable straight from the battery to the converter and it reduced the voltage drop from .9 to .5
When I checked it at the converter last night at 11:00 pm it was 14.25. When I got up it was in normal mode with a fast flash and 13.6

Before starting the charge the SG was 1.230 and it is now almost 1.250 So I have moved the SG less than 1/2 way and its been 16 hours. I know it wont put the SG at 1.275 in 4 hours but something is wrong. The only thing I can think is that the charger needs to be VERY close to the batteries or I need 2 chargers?

It also has good shore power with full voltage. I plan on running a generator this winter so I need to get the fast charge time.
Thanks for any ideas.

[azrving]

BFL13 wrote:
You can use a 40a VEC1093DBD instead of buying a second converter that only does 14.x to use in that role. The 1093 will do 14.8 and also 15.7 for equalizing (which is also how to get the SG back to baseline)

No installation required! 🙂

Next problem is your portable generator limit on how many converters it can run at the same time. The PD already is using a lot of VA.

The VEC1093DBD uses about 785 when doing its 40a. You can perhaps run it and the PD 55 together and get about 90a which is fairly good recharge time on four batts. If the gen won't do both with the VEC at 40a, run it at the 20a setting. That is still about 70a total charging.

I use various chargers all at the same time to get more amps and it works. With the VEC, get it going first , then turn on the converter. Sometimes it doesn't work the other way around.

I will consider the DB as its multi use instead of bolting in. I like the voltages you stated also. So I should be safe at 14.7 and separate the batteries from the house while equalizing at 15.7?

[azrving]

pnichols wrote:

rjxj wrote:
It went into boost mode and I was reading 14.2 at the converter. I was reading 13.3 at the battery bank.

Like others above are saying, that's your problem right there.

For an RV charger/converter to deliver the full amount of current it is specified for and capable of at it's specified output voltage into a battery (that can accept that amount of current early in the recharging process at that voltage right on the battery's terminals), the voltage on the terminals of the battery must be as close as possible to the voltage you measure right on the charger/converter's output. This simple-sounding requirement is seldom mentioned in the advertising or specifications of charger/converters.

Use whatever size cabling and/or mounting proximity it takes to reduce any voltage drop between the charger/converer and the battery to as close to zero as possible during the early stage of charging.

Yes, that was the first voltages I read. I then jumped it with the 4 gauge and the voltage drop did go down to half a volt and never seen higher than 13.70 at the battery. Well, its higher now but that is after running it in boost mode again. I need to do what all of you are saying. I'll run number 2 and supplement the charging at the battery. The SG is now at 1.250 and its been about 21 hours.

As you said the distances were not mentioned and it did cross my mind but the seller said it would work even after explaining that I want to boondock and run only a generator and recharge as fast as possible.

[BFL13]

You can use a 40a VEC1093DBD instead of buying a second converter that only does 14.x to use in that role. The 1093 will do 14.8 and also 15.7 for equalizing (which is also how to get the SG back to baseline)

No installation required! 🙂

Next problem is your portable generator limit on how many converters it can run at the same time. The PD already is using a lot of VA.

The VEC1093DBD uses about 785 when doing its 40a. You can perhaps run it and the PD 55 together and get about 90a which is fairly good recharge time on four batts. If the gen won't do both with the VEC at 40a, run it at the 20a setting. That is still about 70a total charging.

I use various chargers all at the same time to get more amps and it works. With the VEC, get it going first , then turn on the converter. Sometimes it doesn't work the other way around.

[ScottG]

Run the 2 awg battery cables directly to the PDI. Now connect a second set of 6 awg cables from the PDI's second set of terminals directly to the converter fuse board.

You don not need to run the battery through the converter fuse board (like the original wiring) because the PDI has its own set of reverse polarity fuses.

[tenbear]

If you stay at 30' feet of wire here is what you can expect at the battery when the converter is putting out 14.4v at 55A.

Wire size___Volt drop___Battery voltage
___#6__________.65__________13.75
___#4__________.41__________13.99
___#2__________.26__________14.14
___#1/0________.16__________14.24

The actual voltage drop may be greater due to the resistance of the connectors and the ground return path.

[pnichols]

rjxj wrote:
It went into boost mode and I was reading 14.2 at the converter. I was reading 13.3 at the battery bank.

Like others above are saying, that's your problem right there.

For an RV charger/converter to deliver the full amount of current it is specified for and capable of at it's specified output voltage into a battery (that can accept that amount of current early in the recharging process at that voltage right on the battery's terminals), the voltage on the terminals of the battery must be as close as possible to the voltage you measure right on the charger/converter's output. This simple-sounding requirement is seldom mentioned in the advertising or specifications of charger/converters.

Use whatever size cabling and/or mounting proximity it takes to reduce any voltage drop between the charger/converter and the battery to as close to zero as possible during the early stage of charging.

[CA_Traveler]

Good point about the 20A circuit. My charger can be adjusted in 10% steps - so I can reduce the AC draw when on a 20A extension cord. A 100A charger will draw 11A+ AC plus any other loads.

[CA_Traveler]

rjxj wrote:

CA Traveler wrote:
Is it possible to put the charger closer to the batteries even inside the rig?

I could put it under the kitchen cabinet but its not enclosed as its made to go in the converter power center. I'm not against buying another charger and putting it real close. I would like one with higher voltage though. I see that the powermax does 14.6 volts and is 100 amps

That sounds like a good plan given your type of camping. But check cooling and fan noise.

[time2roll]

If you pull wire use the #2. You can step down the #2 TO #4 for the last 12" at the converter. Upgrade the entire loop including ground at the converter and battery.

If instead you pull 120v wire I would probably stick with PD brand and put a PD9280 near the battery. (20a circuit required) If you want real temperature compensated 14.8 volts you may need to step into Xantrex, Mastervolt, or Victron battery charger and the price goes up substantially.

Trouble with Powermax is that it does not hold 14.6 volts. Powermax immediately trips down to 13.6 volts once you hit that trigger. Very close to the battery with #2 will delay the trigger long enough it may work for you and your PD4655 could take over at that point. IOTA only holds 14.6 for 15 minutes before dropping to 14.2 for an extended period (8 hrs?) before dropping to 13.5 volts.

No need to pull both 12v & 120v wire.

[azrving]

CA Traveler wrote:
Is it possible to put the charger closer to the batteries even inside the rig?

I could put it under the kitchen cabinet but its not enclosed as its made to go in the converter power center. I'm not against buying another charger and putting it real close. I would like one with higher voltage though. I see that the powermax does 14.6 volts and is 100 amps

[CA_Traveler]

Is it possible to put the charger closer to the batteries even inside the rig?

[CA_Traveler]

Use a 2 to 4 gauge reducer as close to the fuse board as possible. For all practical purposes you'll have 2 gauge wire.

[azrving]

CA Traveler wrote:

I have 2 gauge also but the lug isn't large enough.

Hole size or what?

An obvious solution is to replace the lug? Lots of places can do that for you.

Its part of the fuse board. It has a set screw that tightens against the cable strands. I can just get the 4 gauge in when I twist the strands nice and tight.

[CA_Traveler]

I have 2 gauge also but the lug isn't large enough.

Hole size or what?

An obvious solution is to replace the lug? Lots of places can do that for you.

[beemerphile1]

That small wire is choking the power trying to charge the batteries.