46 replies to this topic

[Vic Harder]

Ultimate charging ?, no. Get the rated output ?, prob not. At idle ?, nope. But, done right, it might give 10, 20, or more AHs. And that might be enough to help the batts longevity and keep the camper camping, another day.

True.  Especially if the wire has been upgraded to take advantage of short bulk charge burst.

[MidAtlantic]

Help, please.  

I am finally installing a CTEK D250SA in my ATC Bobcat, and have discovered a mystery wire.  It accompanies the green and black wires from the solar panel, which go directly to the solar controller.  A third, thinner black wire (with the blue coupling) goes into the isolator (along with the white wire from the alternator).  

I assume the third wire also comes from the solar panel, but am not sure where it should go when the isolator and old solar controller have been replaced by the new unit.  Anyone have any idea what it is and what to do with it?

 

 

 Bobcat_wiring_resized.jpg   295.23K   37 downloads

[Old Crow]

I believe that's a ground wire.  If you pull the box and look on the back you should see "GND" at that wire... at least according to this R12140B manual.   The diagram shows it running to the house battery's negative post.

 

.

[MidAtlantic]

Old Crow, you've done my homework for me. The manual wasn't supplied with the camper, and I didn't think to try to find a copy. Not sure where the ground goes, but it's not to the battery post. Anyway I can move forward now with some peace of mind. Thanks!

[Old Crow]

You're probably aware of this but I thought I'd mention it for other readers. That ground wire could be useful to you for the D250SA. If you connect the small black wire (the 'AGM wire') coming out of the D250SA to ground, the D250SA will bulk-charge at 14.7 volts (nominal).  If you don't connect that wire to anything, the D250SA will bulk-charge at 14.4 volts nominal.  (It will charge at those voltages at the standard 77*F.  Actual voltage will vary, as it's temperature-compensated via that temp sensor you tape to the battery)

 

Also- be careful not to connect the cables backwards.  The D250SA isn't reverse-polarity protected (nor is it spark-free).

 

Also- If/when you charge your truck battery with a shorepower charger, note that the D250SA will sense the charger's voltage and will connect the truck and house batteries together.  I used a manual thermal circuit breaker (this one) for the D250SA's positive-cable fuse (at the truck's battery) so I can easily disconnect the D250SA or leave it connected as I desire at the time.

 

.

[cwdtmmrs]

Indeed, how did it get so bloody complicated?  JoeKan asks a simple question and it spirals out of control. 

 

While kindly offering his advice to JoeKan, Vic happened to mention an issue with Toyota alternator outputs.  I have a Tacoma with 130A alternator and have never been happy with its ability to charge the camper battery, even after driving all day, let alone the half hour that you propose. Vic suggested two main solutions to my problem (bigger wires and/or a DC-DC charger) and others have added good advice, including pvstoy's well-justified admonition to install a good battery monitor and learn to use it effectively. 

 

So, thanks to everyone's input, I think I have a solution that will allow me to use the truck alternator exactly as you suggest.  But, who ever said life was meant to be easy?

 

I don't get it either. I have one 55 AH Yellow top Optima camper battery that is wired through a simple constant duty solenoid with a #4 cable and a #10 cable to a 120 amp alternator and never once had a battery issue. I don't even have a way to check camper battery as far as voltage or SOC. I don't use as much power since I use a 3-way fridge. I have LED lights, a water pump and maybe run the heater a hour-2 hours a night. I don't even have like chemistry with the batteries. The starting battery is a regular lead acid battery. I am going on my 12th year with the yellow top Optima. I usually drive every day, but have camped 2 days without driving without any problems.

[klahanie]

I don't get it either. I have one 55 AH Yellow top Optima camper battery that is wired through a simple constant duty solenoid with a #4 cable and a #10 cable to a 120 amp alternator and never once had a battery issue. I don't even have a way to check camper battery as far as voltage or SOC. I don't use as much power since I use a 3-way fridge. I have LED lights, a water pump and maybe run the heater a hour-2 hours a night. I don't even have like chemistry with the batteries. The starting battery is a regular lead acid battery. I am going on my 12th year with the yellow top Optima. I usually drive every day, but have camped 2 days without driving without any problems.

 

Perfect ! Simple and it works for you. What more does a person need ?

 

And it shows that such a set up might just work for someone else, in a similar application - as in the OP who I think, got his answer and left quite a while back.