Fuses for Sure Power?

[smithie]

Hi,

As I continue to figure out the electronics in my new-to-me 2010 SMB, I've bumped into a bit of a confusion. My Sure Power 1315 has two in-line red fuse boxes, one is marked "co det", which I imagine is the Carbon Monoxide detector fuse. The other is labeled "sep", and I believe is the fuse for the separator itself.

My issues is that there is a fuse in the "co det" slot, but nothing in the "sep" slot. Would this be causing the house battery charging issues I've been having (as in, my house battery isn't really charging very well or at all)? I'd assumed that the battery was dying on me, but, it seems like a missing "sep" fuse might also be the problem.

Also - if it is my problem, does any one know the fuse voltage I need to put in there? My "co det" fuse is a 3.

PS: I also saw reading the forums that this particular Sure Power may be a recalled model. I contacted them about this to find out and potentially get a replacement.

Thanks all for the help!

[Scalf77]

In general there are not any + side power fuses for the Surepower 1315, It get power from the two battery connections, which if done by sportsmobile will not have any fuses. Depending on when your sportsmobile was built, you may have a fuse on the ground circuit. It should be a 10 amp fuse. If you don't have one you should add it.

Normally the fuses for the CO detectors is located in a fuse box, but it is possible that they attached directly to the house battery side of Separator.

I would look at replacing the Surepower unit.


-greg

[smithie]

So here's a few pictures to help with my explanation. The first shows the in-line "sep" fuse box, which is empty. The second, the in-line "co det" fuse box, which has a 3 amp in it. The last is from my manual, which shows how my version of the Sure Power Separator should work and be connected. All this, to my eyes, seems to say I should have a 10 amp fuse inside that "sep" box in order to get that separator going and house battery charging, and that it will not work otherwise.

Am I missing something here?

[Scalf77]

So I would have to say that sportsmobile got their manual screwed up. The first question I would have is where does the other side of the Sep Fuse go? It should in theory go to a push button switch that is tied to 12 volts, or to the start circuit on your key switch.( It should be hot when the key is in start only).

This enables you to connect the batteries for assisted starting from house battery. The Surepower should operate with the two batteries connected, and the tab that is marked ground connected to ground. The original instruction for Surepower never stated having a fuse on the ground, at one time they changed it, but I can't find a version that has it.

The reason you should have a fuse on ground is to protect yourself from the recall issue. If something is to go wrong with the control module, the power is derived from the battery connections. Any fuse on those connections would be two large to protect the module, besides they are not usually used. With a fuse in the ground circuit , you should have protection in case the control module has some issues.

The control module should monitor the voltages and connect the batteries based off of the voltages on each battery. The start circuit tab, is for start assist and optional.

There isa a video that explains how the Surepower works at http://www.sportsmobileforum.com/for...5-a-14502.html


Also a link from the manufacturer of Surepower http://www.cooperindustries.com/cont...ST_180126a.pdf

Feel free to PM me if you would like.

-greg

[smithie]

Awesome - thank you. I put in the 10 amp fuse and will have a chance to drive and charge the house for a bit this weekend. Hopefully things start working a least a little better until I can get a replacement.

[Scalf77]

To be clear, I don't suspect that putting in the 12 volt fuse would make any changes. While I know the Sportsmobile manual seems to say that a blown fuse that no charge will go from the alternator to the aux battery. There is no documentation from Surepower that supports this. Pulling the fuse, will disable the start assist feature of the Surepower unit. This circuit is listed as optional in the Surepower documentation.

To be honest, this feature has caused more problems than it has fixed. This is probably why the original owner pulled the fuse. If you really think you need a start assist feature it is best to make sure that it is wired through a switch (preferably momentary).

The Surepower 1315-200 can be divided into two major parts, the control module ( the part that monitors the voltage on both Aux and Starting batteries) and the high power solenoid or contactor. The primary contactor they use is the Trombetta Bear-DC-Contactor-Family Part #114-1211-020. Either of the two modules could fail, but the Contactor has the higher failure rate by far. You should be able to monitor the voltage and see if the control unit is telling the contactor to close at the applicable voltages. When the contactor does close you should be able to hear it. You can also measure the voltage across the coil terminals

These are shown in the picture by the yellow & black lines in the above picture. The most common failure in most solenoids is the that it get's stuck in the closed position, the most common failure in this application is that the internal contacts develop resistance overtime. It will appear that the Contactor will close, but there will be no or limited current going across the terminals. This problem is common to high current contactors and is exasperated when the switching current is much lower than the rated current of the solenoid. We have a 225 amp contactor that closes with much lower currents, The closing with lower currents tends to pit and make the internal contacts dirty, higher closing currents actually aid in keeping these contacts clean.

If you are having problems with the alternator not charging the house battery, the primary culprit on out vans has been the internal resistance issue. If you choose to stay with the Surpower unit, you can just purchase and replace the Trombetta Contactor, The best price I have seen is at MurCal Trombetta 114-1211-020 DC Contactor

I have seen some websites say they sell an upgraded version, part # 114 1211-010, this is the same unit with copy terminals, the -020 unit uses Silver Alloy terminals which is actually better for contact resistance problem.

There are also other options out there to replace the surepower unit with, you can search and come discussions on that. Most people have switched over to one of the Blue Sea units (I believe this includes Sportsmobile also)



-greg

[smithie]

Thanks Greg - I certainly appreciate the time and help. A bad Contactor is sounding about right. The house battery does charge, just not much and very, very slowly. Replacing the Contactor with a new Trombetta will be a first effort at getting this charging process to work better. It's a whole lot cheaper than replacing a bad House Battery, which is a secondary suspect...

What you mentioned about start assist made a whole a lot of sense too, so, I pulled that 10 amp fuse back out - I want nothing to do with that system's potential problems.

To reveal the depths of my electrical ignorance, I assume I should remove all grounds first, then start removing positives when swapping out the Contactor?

[Scalf77]

Yes, that would be a good approach. While you are changing out Trombetta , you may want to add a 10 Amp fuse in the ground line for the Surepower unit. I also use to run a. switch in line with the ground, to act as a disable switch. Just things to ponder while your in there.

greg