APU Tri-pac not charging batteries

I am having a similar problem with tripac not keeping batteries charged. For about the last 8 days I wake up and batteries have just enough charge to start the truck, on a couple of the days I actually had to shut off everything in the truck and just let the tripac run on its own with no a/c or anything for about 30 minutes just to get enough charge to start the truck. Once the truck engine was started and run for about 20 or 30 mins and shut off, it would crank right back up no problems, not straining to crank or anything. Took it to Thermoking in Baltimore, they told me that as long as the Tripac is not throwing the "Alt" code that the alternator is putting out the correct voltage and is not the problem. I told him my whole story so he hooked it up to his meter and said the Tripac alternator was putting out 13.8V or better at the batteries.
I have a 2000 watt inverter and the voltmeter on the inverter however was only reading between 12.4V and 12.8V with the Tripac running and a full 14.1V or 14.0V with truck running.
Going by what the guy at thermoking saying that the tripac alt is putting out 13.8 to the batteries I went ahead and assumed that maybe my inverter voltmeter is not 100% accurate and it was maybe the batteries that were bad, so I went ahead and replaced all four of them.
Let me back up and say also that I am running a steady 200 to 250 watt load on my inverter pretty much all night -freezer which uses only 120 watts, computer and flat screen TV, plus a 12V fridge and few dome lights maybe another 100 watts total for a grand total of *maybe* 500 watts once you include the a/c blower (all of which tripac should have no trouble with).
I also have a 850 watt microwave used for maybe 20 mins a night (which I haven't been using at all since all these electric problems started) but have on a couple occasions had it run maybe up to an hour and where it has really deep discharged the batteries, so I was thinking maybe it is me that screwed up the batteries with my overuse of the microwave really discharging the batteries too low and screwing up one of the cells. Even then I only would ever use the micro with the tripac running, so theoretically I shouldn't have really been drawing that much off the batteries, most of the power should have been coming straight from the tripac, but I digress.
Anyway so I replaced all 4 batts today, now I am sitting here tonight with tripac running and the readout at the inverter is still 12.7 which I am pretty sure is going to leave me dead or pretty close to dead come morning. Got my fingers crossed but not too hopeful. I just keep wracking my brain to figure out just what the heck it is. My next guess just from reading earlier posts on here is it is maybe a loose wire or ground somewhere between tripac and the batteries, but then how did the guy at thermoking get a 13.8 reading? And if it was reading 13.8 for him maybe it was just a momentary fluke? I also should mention that my low voltage protector never shuts off aux power for the lights/radio etc. and that tripac A/C and blower and all electric stuff (fridge tv etc) runs just fine for 15+ hours so I know that the tripac alternator is at least putting out SOMETHING at least enough to run all my appliances!! Inverter is hooked up directly to the batteries so the tripac has to be putting at least enough current to the batteries to keep appliances on, and like I was saying before I can run this stuff all night long and voltmeter at inverter still reading between 12.4 and 12.7V. However, shutting off ALL electrical appliances including the tripac A/C fan and just running the tripac motor itself was leaving the voltmeter up from maybe 12.4 or 12.5 to maybe 12.9 at the highestm still leaving me in the same boat of barely alive batteries after 10 hours. So shouldn't I expect even with only 12.9v output from the alternator and no other current draw that I should have batteries that would not seem to be straining to crank? This was the reasoning behind going ahead and replacing the batteries, which I still hope is the problem but the pragmatist in me says it probably will not end up being the solution.
So I am feeling really lost here. Any help any of you have to offer is much appreciated, and I will try to update again for the next couple days once I finally get this all nailed down. I think I may also try to get through home and tinker around and see if I can't take a closer look at the whole setup myself and try and regain my sanity!!

 

he may have been getting the 13.8 reading right at the alternator on the TriPac, but if you are showing in the low to mid 12's while it is running it is either one of 2 things. Either it is not putting out enough amperage, or the unit itself is not grounded well enough. I have had both problems.

 

Where isthe ground cable located? Does it come directly off the alternator? If thats the case I'm guessing that shouldn't be too hard to fix or replace.

 

Nick it seems like we have the same problem. The ground comes off the back of alt and is a thicker wire like the positive one. I wiggled all the wires on back of my alt and everything seems tight, as well as i could with just the access panel off. When i get home im taking the whole bottom cover off and disconnect the wires and clean the connections. Otherwise im at a loss like you. If you figure it out please come back here as i will..thx

 

Thx for the replies Hardly, so if the alt is not putting out the correct amperage its bad? Wonder why no code is thrown. I dont see how the ground could go bad unless the nut came loose, i checked that and it seems tight. Will see better when i have better access to it. thx agn

 

The unit get's it's ground by how it is bolted to the frame. This may not be a good or get corroded. I ended up running a battery cable from a bolt on the block of the Tripac to a grounded bolt on the truck frame rail.
The alternator is capable of putting out voltage around 13.8 but at only a handful of amps. The only way to tell if it is working at capacity 65amps, is to use a load tester, not just a voltmeter.

 

Nick, Chris. I was having a very similar problem as you guys. The starter on my Cummins ISX ending up going out one evening, and had to get a shop truck to bring me one out. New starter installed, no more dead batteries in the morning. Although I still think I have another parasitic drain on the batteries somewhere, its just not enough to pull the batteries down enough to prevent starting.

I "think" the culprit was the battery connection at the starter solenoid (on my big engine) that was causing the Tripac to not be able to completely keep the truck batteries maintained. Once or twice previous to the starter dying for good, I wrenched down on that solenoid nut, and voltage picked back up again. I truly don't understand why, as Tripac battery cables go directly to the batteries.

Inverter voltage would read 12.2 or .3 volts and truck voltage was reading 12.7 or higher. They should always read exactly the same. My inverter wasn't able to make full AC volts and was down around 102 or 103 volts which wouldn't let the microwave run. I would always have to start the TriPac or even the big motor to get the inverter to make enough voltage to run the microwave. Even then sometimes that wouldn't be enough. My batteries are only a year and a half year old. I have load tested them. Since the new starter has been installed the inverter reads 13.5+, but the truck is still only showing 12.7 volts.

My guess to you guys, somewhere there is a bad ground or battery cable not getting good contact.

Do you guys have the factory Tripac battery cable with a "T" in it for the inverter connection? I wonder if getting rid of that and bringing the inverter cable directly to the batteries wouldn't help in some way?

I keep thinking that the big engine acts as a parasitic drain on the Tripac alternator while its running, preventing full battery potential and there may even be the same effect with the Tripac when the big engine is running? Kinda like the current is hitting the diodes in the alternator of the engine that isn't running which in turn blocks the current from its return path. I know my idea is only half baked and I dont have the electrical knowledge to know if its possible for that to happen. One of these days I need to call somebody like Hellroaring and find out if they have experience with this kind of problem.

 

Maybe that starter thing is something I'll have to check out. Without going into detail my starter has been acting up lately and I've been needing to get it checked out. And as I suspected I'm still getting somewhat of a drain. The new batteries are handling it better than the old ones and I put marine batteries in here to make sure deep cycling wont end up ruinin them right off the bat. Still puzzled so but now I have a couple more places to look. Haven't had time yet to get under the tripac and check the ground but that will be my next project.

 

Kansas- my inverter reads the same as a digital gauge i put in for the truck, running or not, but i will definitely check the starter bolts for tightness to eliminate that.

I am going to check and clean every connection to the batteries and the apu i can find and then im buying a new alternator to try, if it fixes it great, if not i have a spare for down the road. thx agn to all of you for input, no idea is a bad one!

chris

 

Before purchasing the Tripac I have now, I also spec'd the Extreme Arctic Package that Tripac offers. That package includes an upgraded 120 amp alternator, and its the only way you can get your Tripac with that alternator. I dont have the part number for it, and I dont know if its a simple swap. You may have to change out brackets and wiring harness too, I dont know...? Good luck finding any information on it, I had to threaten my dealer with the idea of taking my business elsewhere before theyd give me any info on the Extreme Package. Apparently its not a very popular package, and my dealer just didnt want to take the time to investigate for me. To further antagonize the problem with the dealer, Tripac was reengineering their Extreme Arctic Package at the same time, so parts numbers were changing making it really frustrating to get accurate info.

Standard Tripac "currently" come with a 65 amp alternator. Although I think they have changed the available amps on their units about half a dozen times by now.