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.

[wa8yxm]

Well, your 2 pair can take a charge of nearly 150 amps if you have that much converter (you do not) so you can upgrade the converter to the biggest PDI makes and shorten the run with much heavier cable.

or shorten the run (What I would do) and put up with the longer charge time, since withing reason the SLOWER re-charge will make most battery types last longer.

[azrving]

smkettner wrote:
Did we recommend pushing 55 amps 30' through #6 to charge 4x GC2? 😞

#4 direct is an obvious help. If pulling wire consider pulling 120vac to mount the converter close to the battery. NEC is not very big on parallel conductors so you need to replace the #6 or move the converter.

Possibly a second converter to clamp on the battery when fast charge is wanted. Although it may actually work good enough as is so maybe give it a go. The hydrometer should rise within a week and with some exercise this summer I am thinking the charge time will improve.

No, I dont think anyone here recommended it and I had my doubts of it working when the the person I bought this from said it would. I emphasized over and over about what I'm trying to accomplish and he said 6 gauge would work. I trust you guys because as you say its not guess work and you have already gone through this.
While crawling around under this thing I was amazed from day one that they run the battery wires from the converter to the other side and down the frame rail and back over to the batteries.

Ok so I will replace the 6 gauge to the converter with 4. I have 2 gauge also but the lug isn't large enough.
I can run 120 back to the battery area and install another charger. What would you buy that will do more than 14.4?
Would you isolate it from the pd4655 so they are not both connected to the batteries at the same time? Shut the breaker off for the pd4655 when using the other charger?

[MrWizard]

Two things
To go from 90% to 100% takes at least as much time as it took to go from 60% to 90%

Also SG will always lag behind voltage, it takes several hours to stabilize
After charging stops, SG keeps rising, If there is no load

[time2roll]

Did we recommend pushing 55 amps 30' through #6 to charge 4x GC2? 😞

#4 direct is an obvious help. If pulling wire consider pulling 120vac to mount the converter close to the battery. NEC is not very big on parallel conductors so you need to replace the #6 or move the converter.

Possibly a second converter to clamp on the battery when fast charge is wanted. Although it may actually work good enough as is so maybe give it a go. The hydrometer should rise within a week and with some exercise this summer I am thinking the charge time will improve.

[azrving]

NinerBikes wrote:
Get that charge controller as close to the batteries as you can get with the four gauge wire. you will still need a manual charger to get the voltage at the batteries up to 16.0 Voltsto equalize charge the batteries.

Thats what I was afraid someone was going to say. 🙂 Well not afraid but I know how voltage drop works so I'm not surprised. Ok so lets just leave the pd4655 where it is. I like it and it seems like a quality product so lets just move on to what else I can do to make this work as fast as possible. Should I just buy another charger and mount it close to the pack for the times I need to hammer it quickly? What should I buy. As I go to a high charge voltage I dont want to damage my frig so should I isolate and do 2 banks? One to keep things running while the other charges?

[BFL13]

rjxj wrote:
The original wiring is about 30 feet of 6 gauge. I have installed a 4 gauge wire straight from the battery to the converter during this charge/test and the length is about 15 feet

15 feet is too far for 4 AWG to keep the PD near 55amps. Better than 6 AWG though! You can improve things by leaving that 15 ft of #4 on the pos path and using the frame for the neg path (as now?) by running another 15 ft of #4 to parallel that first wire. That will much reduce the total R of the pos path and the frame already has decent low R.

You can also run more wire to parallel the frame path on the neg side to improve the R on that. However the payback isn't as great as doubling the pos path, since the frame already has low R.

The R that counts is the total R of the pos and neg paths, so improving just the pos or neg path is a help. If you reduce the R on both even better but they don't have to be even R. It is the total that matters.

[NinerBikes]

Get that charge controller as close to the batteries as you can get with the four gauge wire. you will still need a manual charger to get the voltage at the batteries up to 16.0 Voltsto equalize charge the batteries.

[Mandalay_Parr]

I would give it 24 hours.
The last part goes slow.

[azrving]

The original wiring is about 30 feet of 6 gauge. I have installed a 4 gauge wire straight from the battery to the converter during this charge/test and the length is about 15 feet

[BFL13]

rjxj wrote:
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.

How far is it from battery to converter? 6AWG isn't very fat for anything over two feet.

Your SG looks like the 6s have been sitting below full for a while. You can't get the SG up doing 50-90s. After a 50-90 the SG will still be low. It will take more time at 14.4 to get the SG up--use the manual boost to keep the voltage up till it gets done.

55amps on a 440 AH bank, to do a 50-90, will take about 5 hours. Then the 90-100 will take ? another 10? hours