Trucharge 20+ Questions

[Sundance]

I am planning to install the Trucharge 20, and have a couple of questions.

First, looking at the installation instructions it recommends placing fuses or breakers between the charger output and the battery connection, I assume an inline fuse would work well, but I am not sure what size fuse is needed.  The largest output from the charger would be 14.8v, but not sure how to equate this to a fuse size in amps.  Is the fuse even necessary?

Second, I can't seem to find any information on the remote panel for the Trucharge 20 as to the dimensions of the unit.  If anyone has one and can give me approximate dimensions I would appreciate it.  Also, if anyone has any recommended place to put the remote panel please let me know.

As always, if there are any pointers or tips on the install, or the product in general please let me know.

[Craig Illman]

Jeff - I just went through the fusing with a friend that has a ProMariner 40. She kept blowing 30 amp fuses to her house bank. In the ProMariner manual, it recommends a fuse about 10% over the maximum output amps. So you need at least a 22A fuse. The Truecharge manual says it won't output more amps than it's rated for, so you need to place the fusing as close as possible to the battery end of the cabling. You're trying to protect the wiring. Sorry, I don't have any information on the remote panel. My remote panel for my Xantrex is at the Nav table, just above my Link 20 display.

Craig

[Sundance]

So 25 amp (DC rated) inline fuses (one per charger output) located as close to the battery would be best.

Any guess as to the remote panel dimension, are we talking 6"x6" or 3"x3"?  I don't need exact dimensions, but just looking for approximate size.  My fear is I order it and it is huge, like 12"x12" and I have no where to put it.

[Jim Price]

I don't remember the exact dementions for the remote panel - the documentation that came with my +20 does not list it either - but is it is around 4" to 5" square and may be 1" thick - just guessing. 

I mounted mine on the hull trim above the nav table (on the radio shelf).  I did not want to cut any more holes so I made a simple wood frame from oak (like a picture frame) and mounted the panel in the frame and used velcro strips to attach the wood frame to hull liner trim.  It has been in place for 4 years and looks like it is part of ash panel.  Wires run out to side but are behind the VHF so no one sees them - used hole in shelf for VHF wires to run panel wire under sole to batteries .

[Craig Illman]

Jeff -

Here's what I found with Google: http://www.jackrabbitmarine.com/Detail.bok?no=3295

Dimensions 4 7/16" x 4 7/16"
Mounting hole needed approx 3 3/4" square

Craig

[Sundance]

You're good.  I looked high and low and couldn't find that info.  Thanks.

[Mike and Joanne Stimmler]

Craig, you ARE good! I've added Jackrabit to my favorites list and their prices are much lower than WM.

Mike

[Jon Schneider]

None of us can tell you what size fuse you need until you say what wire gauge you're using, but here's how you can determine the fusing size for any application: http://beta.circuitwizard.bluesea.com/# 

As Craig said, you're protecting the wire, but actually you also need to protect the instrument, so the fuse size should be whichever is less tolerant, the wire or the instrument/application.  For instance, if I had 4 awg wire feeding a 10 watt instrument, I wouldn't go to the 150 amp fuse that the 4 awg wire could tolerate; I'd size it for the instrument in that case.  In your case, the battery can take a fair amount of abuse, so the wire will be the controlling amp factor.  BTW, fuses in general get placed as close to the source of power as possible.  In the case of your charger, the charger is the source, not the battery. 

[Craig Illman]

Jon - Very good point!

Craig

[Ron Hill]

Jeff : Here's what I did for my Xantrex True Charge 20 installation :
As I recall I used #8 wire as it went from under the nav table, under the floor to the batteries in the aft settee seat.  That requires a 25amp fuses in each of the 3 positive wires. 
The trouble that I found was finding a small fuse holder rated for 25 amps.  Most of the fuse holders and in-line fuses holders are rated for 20 amps. 
I finally found a Blue Sea AGC fuse block that is rated for 30amps.  It had 6 positions, but I was short of space (in the battery compartment) so I cut it in half.  It works great and the 1/2 cover stays on with a Velcro strap.   

[Jon Schneider]

To build on Ron's point, I used #6 awg cable with ATC-type fuses (AGCs and ATOs have multi fuse blocks, but I didn't need that because I only have one bank in the starboard settee, while my starter bank is aft of the engine).  I have a Xantrex 30 amp charger (same company as the maker of True Charge) and their recommendation based on the length of wire needed was #6 awg, which is beefy stuff (purchased for an incredibly good price at bestboatwire.com).  I used 40a fuses because my rule of thumb (well, someone much more electrically adept than I told me this) is go with +25% over the rated output of the device if the wire and application (in this case the battery banks) can tolerate that.  Sundance, if you go with an ATC-type fuse (www.jackrabbitmarine.com/Detail.bok?no=2734), the smallest you can buy is 30 amp, but short of using 18 awg wire, which you wouldn't do for a charging application, you'll be fine.  I suspect, BTW, that Ron's cut-down AGC fuse block actually has a smaller footprint than my two separate ATC fuse blocks, so if space is a consideration Ron's way is the way to go (which it is normally anyway).  BTW, Anchor makes an inline 30 amp AGC-type fuse holder and there are also inline ATC fuse holders, but 10/12 awg is largest gauge wire they'll accept. 

[Randy and Mary Davison]

Jon,

Good info but I'd like to argue one point.  You are correct that the fuse should be nearer the source but the batteries are a far far greater source of potential current than the charger.  The issue is fire.  If the wires short at the end away from the charger, the charger dies but the number 4 wires hardly heat up at 20 to 30 amps.  On the other hand, if the short happens at the charger or in the charger, the batteries will happily dump more than enough current to slag the wires and start the insulation and anything else close on fire.

Both the charger AND the battery are sources and the battery is the more dangerous one!  Personally, I put the fuse blocks and breakers near the batteries so shorts anywhere else in the wiring keep the stored energy where it belongs - in the battery.  I suppose you could put fuses at both ends but you'd need to watch the total resistance buildup.  I haven't run the calculations.

Randy

[Jon Schneider]

Randy, I think that logic makes a lot of sense.  That also seems to be the way Ron configured his system.  For my own system, I'm not so worried, because my charger source terminates on the 150a battery fuse, which #6 awg wire is capable of handling. 

[Stu Jackson]

Fuse size:  doesn't Figure 2-2 on page 2-4 of the manual tell you what size fuse to use?  (http://www.xantrex.com/web/id/462/docserve.asp)

[Ted Pounds]

Another reason you're not concerned about the charger starting a fire is that the charger is (or should be; the Truecharge is) internally fused.  That would take care of any short from the charger's point of view.  So the real concern is, as has been stated, the batteries.