As per the sketch I have a 6 awg wire from my battery fuse box about 12' run up through the floor into a large wire nut then 8 awg to a battery switch( the kind you pull in and out) then 8 awg to my DC panel.
Here is the problem, I have a pd4655 charging 2 6 volt batteries and it goes in boost mode no problem but I am only getting about 25 to 30 amps when the battery is low. Is the wire size the problem? Should i replace the 6 awg with a 3 awg? Are to parallel 6 awg's better? I have 2 problems with that, 1 the terminals on the battery switch are tiny . 2 The lug hole on the DC panel can hardly fit the current 8 awg that is in it now. I can run the 10 awg wire straight from the DC panel to bunk beds so that is not a problem. Any suggestions on how to improve my situation here? I saw a fellow on youtube that did the very same operation and was getting 56 amps after going with 3 awg. he didn't address the lug size or battery switch issue. Sorry so long but any suggestions are welcome. Thanks
Is that a blue or large grey wire nut that connects the #6, #8 and #10 together?
Where does the battery charger connect? If it connects to the DC distribution panel, that is your problem. And I would first move the #10 wire directly to the battery disconnect. It should already be circuit breaker protected for 30 amps or less. Then change the #8 wire to #4 wire, it is good for 100 amps, and run that from the battery disconnect switch all the way to the battery.
The #4 wire can be protected by 70 or 100 amp circuit breaker, or pair of 40 amp automatic re-set circuit breakers.
To make wire connectors for the end of my #4 wire, I used 2" long 1/2" soft copper tubing. I smashed the last 1-1/2" in a bench vice, folded it over on itself, and drilled a hole in that end. Inserted the wire in the open end, and clamp down hard on the vice, it is now good for about 100 amps. My connections worked fine for about 10 years.
You can get some improvements by re=arranging the wiring, but first, to learn if it would be worth the bother, you have to define "Low" when you say the batteries are low and it only does 25-30 amps.
How long will it keep doing that many amps before tapering to 15amps etc?
Also anything else on at the same time will subtract amps from the converter. Anything there?
A PD will taper its amps sooner than others so the time you get full amps will be very brief no matter what you do, so you have to compare that 30 amps with what it would do if you did the mod. It can then be estimated how much that would shorten your charging time from whatever SOC you start the recharge at.
It is possible the best you can do will only make a few minutes difference or you could speed things up by half an hour. Is a half hour worth the bother for how many times you do a 50-90 while camping before getting shore power?
Once that is all solved, the details of wiring change options are easy.
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Measure the voltage at the converter output. For a ground lead run a temporary wire out to the battery negative post. Measure the voltage at the battery using the same long ground extension on the negative lead. If you are actually losing current due to a voltage drop through those wires you will see a difference in the readiings. If they are very close then the battery itself is only allowing so much current due to internal resistance which may be fine. A deep cycle battery really should not be rapid charged for best life.
When you do these tests be sure other items are turned off such as lights etc.
first i will describe the pics. the first one is where my 6awg goes on the battery side. Its the bottom left red wire. from that breaker it now has a 2/0 cable from there to the battery. The second picture is the jumbled mess where all my wiring goes. The 6,8,10 junction is the blue wire nut covered in electrical tape towards the left side of the picture. Thats how it came from factory. Now I will answer some of the questions if it helps.
When I say low battery I mean 12.05 volts or less. I didn't do a time test but I know the highest amount of amps are 30 then it tapers from there. I boondock camp 95% of the time so a quick recharge is crucial. I don't like listening to the generator. I don't have any other things on while the batteries are charging. That 6 awg goes to an 8 awg then to a battery switch then into the DC panel /converter area. Is that a problem? thanks in advance
Is this breaker/switch in the charge line from the battery to the converter?
I evaluated a 100 amp one of them and found that it dropped almost .2 vdc at 50 amps...Way too much for any converter to properly charge battery (s). They are ok for protection of other circuits though.
That coupled with other wire/connection issues will drastically cause a converter to under perform. It does not take much.
Not clear how much of the DC panel to battery path is #6 and how much is 2/0. I it is mostly 2/0 you can't beat that, so the fix would be to use fat wire for the neg path instead of (or in addition to ) the frame.
One thing to do is eliminate all those miles of #8 for the battery switch wiring that adds to your converter-battery path now, and just put the #6 and # 10 in with the #8 at the DC panel lug, using a short length of that existing #8 as a pigtail from the lug (where it fits on ok) Use same wire nut ?
Then for a battery disconnect just take the neg wire off the battery when you want. Or put that same switch there right by the neg battery post.
What gen are you using? AC input quality will affect the amps put out by the PD. if a Honda or similar inverter type, you are ok there, so that wouldn't be a cause of lower Dc amps.
If you count the red wires on the left side of the picture the 3rd one down goes to the 6,8 ,10 junction in the first post, then to battery switch then to converter. on the right side of that breaker is that single red wire. Now that is a 2/0 wire and that goes straight to battery. I should say this is my first trailer so to me this is a typical setup but if it is not and there is a much better/efficient way i am all ears for a suggestion.
I can't really say, not being there, but I don't see any 2/0 which is really fat. It looks like you have #6 from the battery coming in from the right to the resettable breaker ( with the black button) and then two #6s going to somewhere (slide and jacks?), and a #8 going to that little circuit breaker and then off somewhere (what you call the third wire down?) and also a #10 going off to somewhere through its own little circuit breaker.
It is correct that the two smaller wires have their own little circuit breakers according to their own wire sizes where they come off the buss (the big breaker acting as a buss in this instance)