Pulse tech in a m923 problems.

[Plane Fast]

I went ahead and just started a new thread specific to the 939 series.

Well i finished and installed my Pulsetech PDU with solar panels.
I gave it a good solid week for a good test of the charging capability.
Did not go well!

History of my truck.
This truck has never had an issue with starting nor weak batteries. No matter how long I let it sit. Fired right up, with just a bump of the starter. (Month or more)

I drove the truck for about an hour before I parked it and finished the install.
This is a rough diagram of my wiring.
Here are the components.

Although I'm using two small solar panels. Voltage was very good off both units.

The week long test had sunny sky's almost everyday.

Well, went to start the truck.... Nothing dead as a door nail!
Crap. So I checked voltage on the batts. All but one was good.
Hooked up my battery charger to the weak batteries and charged them up.
No dice. The lowest battery will not hold a charge over 9 volts and failed the load test.(#4)
So I disconnect the two weak batteries and tried to start on the two good ones.
It would just barely turn over. No start. I charged the batts longer and then use the start assist on my charger. Got the truck running. (Barely)

So I load tested all the batts. The #1 and #4 failed.

From my pic the batteries would be top 1 2, then bottom 3 4.

So now I have to figure out why it killed all my batteries. I find it hard to believe that the Pulsetech could short out two batts. I have all of it disconnected now. Not sure if I can get back the one batt(#4)

Guys with alternator knowledge. From looking at my wire diagram. Do you think it is possible that the one battery was failing and the charging system could not equalize the load? Because the two bad batteries are the first and last ones in the charging system.

 

[cagosti]

I'm not much for typing but if you want ' give me a call
I can help
charles
269 217 4188

 

[gimpyrobb]

I helped install one of these on Guns's truck. I wasn't real impressed with them to tell you the truth. It pains me to see all the 12v leads without a converter or equalizer built in.

Did you have any 12v circuits installed and pulling power?

 

[juanprado]

Where they are OE the 12v usually comes off the dual voltage alternator 12v stud. I don't think it meant to be tapped off the batteries unless a converter/inverter is used. I think your problem is the 12v hook up.

Also, the OE solar panel is one large one not 2 small ones. That could also be a problem. Is the 3 pin connector going to the tester wired correctly from the solar panels?

Is the red pulse light working?

Call pulse tech as I found their tech dept answered some of my questions.

I have the 24v hooked up only with the OE panel and been happy with it. I am waiting to install an inverter before I hook up the 12v side.
Pulse tech did tell me the unit has some very proprietary desulfating expensive gizmo underneath the fuse panel to pulse the batteries and keep the parasitic loss to a minimum from sitting up.

 

[Plane Fast]

I'm not much for typing but if you want ' give me a call
I can help
charles
269 217 4188

Thanks. I'll give you a call.

 

[Plane Fast]

I helped install one of these on Guns's truck. I wasn't real impressed with them to tell you the truth. It pains me to see all the 12v leads without a converter or equalizer built in.

Did you have any 12v circuits installed and pulling power?

No, I did not wire anything to the PDU yet. (Just tested a new light for a minute)

 

[Plane Fast]

Where they are OE the 12v usually comes off the dual voltage alternator 12v stud. I don't think it meant to be tapped off the batteries unless a converter/inverter is used. I think your problem is the 12v hook up.

Also, the OE solar panel is one large one not 2 small ones. That could also be a problem. Is the 3 pin connector going to the tester wired correctly from the solar panels?

Is the red pulse light working?

Call pulse tech as I found their tech dept answered some of my questions.

I have the 24v hooked up only with the OE panel and been happy with it. I am waiting to install an inverter before I hook up the 12v side.
Pulse tech did tell me the unit has some very proprietary desulfating expensive gizmo underneath the fuse panel to pulse the batteries and keep the parasitic loss to a minimum from sitting up.

The instructions I found for the PDU. Said to run the 12volt off the same battery as the PDU ground.(to get just 12volts)
I tested the PDU, and it would only pulse with the 24 volt lead and ground hooked up. So the 12 volt should not have a draw with nothing connected. (Or fuse in)

Whats weird is the battery with the PDU ground and 12volt lead. Had the best voltage! The sun was down at this point, so no help from the panels.

I do have the two panels wired into a 5 pin DIN connector going into the battery solar charging unit. The max input for it is 750 mAh. The panels are close to that.

PDU LED has been working the whole time.(pulsing as it should)

I will try and call Pulestech as well. Although they did give bad advice to a SS member in another thread.

One other thing I just remembered. When I check the batteries with the sun out. Two of the batteries show 16 volts.

 

[juanprado]

I think the 12v is causing an inbalance in between one bank to the other but there are others who are much better versed than my limited skill set...who can hopefully give you answers.

I would try removing the 12v lead, charge and test all 4 batteries and see where you are?

 

[Hard Head]

This unit runs 24 hours a day on your battery power. It has a pulsing circuit embedded on the 24v lead. You will see a red led showing it is pulsing. I have 2 of these units and just rely on them for fuse boxes for lights, fuel primer pump and while driving pulsing. I still use a pulse tech dedicated xtreme 2 charger per pair of batteries that I keep plugged up every day. I really like battery disconnect switches. I have a main switch / relay and 2 more flaming river manual switches for winches on my truck. There are other ones on the market but this is what I use.

http://www.flamingriver.com/index.php/products/c0015/s0007/FR1009#

In hindsight I will use the automatic relay switch on my next truck.

http://www.flamingriver.com/index.php/products/c0015/automaticbatterydisconnect/FR1051#

 

[emr]

Before using a tender , FULLY charge EACH batt with a real charger, one that puts in 13.6 volts min, and preferably a smart one that will change the rate from 12 to 15 when needed to charge FULLY these big batts, I see many have trouble with batts on this site, Its not the batts, It that the batts never get fully charged, These puddle jumper chargers will never fully charge a low batt of this size, even though it will get to a point that the trickle surface charge puts up enough resistance to tell the puddle jumper its done, NO ITS NOT ))))))))))))) EVEN after a month or two of maintainers, ALL batts should be routinely fully charged and rotated annually for them to have a maximum service life. period. Extreme cold, or heat or just time will drain the batts to where little baby chargers don't have enough umph to bring it back up, AND to top it off, Using trucks only now and then like we do NEVER fully charges batts, You / We would need long hauls to charge AL the batts in these trucks, So most are not realizing they are killing there batts, By never fully charging them when needed. Batts need to be full to have the absolute least amount of sulphation. One can keep batts off as off can be, they still lose juice month by month . And then need to start the truck and then usually don't have a long enough drive at one time to fully charge em, ALSO ... The last batts in line never get fully charged unless YOU DO IT ))) Good luck )

 

[Plane Fast]

I decided to take out the load failed batteries. I will try to recover the better of the two if I can. Had a good talk with Charles about the Pulse tech system.(posted above)
We both think it's unlikely that it fried two batteries in 5 days. So that leaves me with the possibility that one battery was on the way out. This just happened to coincide with the install.

Looks pitiful losing two batts.

I went ahead and hooked the PDU system back up, minus the 12volt lead. (Easier to find a problem)
So far every thing is testing well. Truck started right up.

Im going to take load and voltage readings for a few days.

 

[Plane Fast]

Yeah EMR. I have found that the small chargers will only hold a voltage. I use two professional 12 volt chargers, that can run from 2 amp to 200amp(start function). I really did not need to use it on this truck until now. The specific gravity and voltage has been good. (Until now)
I think it was my number 4 battery that was dying. This took out the 1 battery.

I may just keep it as a two battery system for now.

 

[Plane Fast]

Disregard...
I'll ask this question in another thread.

 

[tim292stro]

Meant to post to this thread but it slipped off the radar...

The PDU is not part of the maintenance function of the PulseTech unit. If you don't need 12V distribution don't hook it up. You should only need the solar panel and the pulse unit. As others have said on this thread already, the amount of current the solar panel will output is not sufficient to do much charging - the common 6.3Watt panel only puts out (6.3Watts / 24Volts = 0.2625Amps). It is enough to keep the low power of an truck with an ECU that draws a few milliamps of power to retain the memory from draining the batteries over time.

If you have AGM's like a Hawker Armasafe Plus (EnerSys/Odyssey 6T-AGM), that little panel is nowhere near the minimum charge current to do any recovery (0.4 * C10 rate), the Hawker Armasafe Plus (Odyssey PC2250 - same guts, both from EnerSys) needs at least 50Amps to charge. This would mean that a 24V string of only two batteries would need (29.4V * 50A = 1.47kW) solar setup to do any meaningful recovery charging... A 4-battery 6T-AGM series-parallel setup would need just about 3kW of solar to make ny useful recovery charging happen. 6.3Watts is 0.0063kW by the way... Better to run that 100-200Amp alternator until the ammeter shows less than 10Amps being sent to the batteries before shutdown, or pull them out and charge them in a shop.

Sucks about the batteries, but this happens this time of year, when a marginal battery needs more start current to support the cold weather starts the weak ones fall out of formation, and the cell voltage suffers due to the slower chemical reaction rate.

 

[jarhead1086]

My Pulsetech showed all four lights all summer. My garage stays above freezing but it drops to 75% charge quickly after charging with my weak OEM alternator which isn't much better than my cheesy battery charger. This explains why I need to get a new high amp alternator. I have a keyed battery cutoff switch was has helped greatly if you remember to use it after all the other post drive checks.

 

[tim292stro]

...This explains why I need to get a new high amp alternator...

This is why HMMWV/CUCV with a single pair of 6TL and an expected comms accessory load come with a 100Amps of alternator (single 24V for HMMWV, dual 12V for CUCV). M939 series trucks aren't expected to be run as "radio trucks," so they don't account for any significant accessory loads - with dual strings of 6TL the minimum to charge and run things like headlights and intermittent accessories like CTIS, only need that same 100Amps. If you plan to run more stuff than the factory installed, taking a look at the whole power situation is worth it in the long run.

...I have a keyed battery cutoff switch was has helped greatly if you remember to use it after all the other post drive checks.

"Vampire loads", little computers that suck a few milliamps per day (engine computer, CTIS controller, pushbutton master vehicle light switches, etc...), will suck a battery dry in a month or less. Yes, if you plan to store for any length of time longer than a few weeks, it's actually best to pull the batteries and put them on a charger/maintainer in a warm place (not sitting on cold concrete).