Deltran 24-volt charger

[Jon_Gilbart]

I've been searching through threads on charging, but haven't found what I'm looking for... I will search for the REAL answer to my electrical problem when I have more time, but for now, I just want to hook up my Deltran 24-volt charger to my 2 Optima red top batteries. After charging them fully (independently, outside of the Pinz, w/ 2 different 12-volt chargers), I put the batteries back in my Pinz and after running fine for 2 days, I tried to start it today and it didn't have enough juice to start. I plan to check into the problem when I get a chance (molex connector, charging system, bad battery, parasitic draw that is drawing power EVEN though the battery disconnect thing is removed, etc.), but for now, I would like to get the charger hooked up and NOT blow anything up in the process, if possible. I figured that I would hook the red terminal from the charger to the positive terminal on the upper (left-most) battery and the black terminal from the charger to the negative terminal on the lower (right-most) battery. I then plan to plug in the charger and get going again! Is this ok or do I have to attach the black terminal on the charger to a piece of sheet metal or something else0? Also, is it ok to use the 24-volt charger with the battery disconnect behind the driver's seat either in or out or does it make a difference? Most people I have asked about where to hook the negative terminal from the charger (as it pertains to regular 12-volt automobiles) say it's ok to attach the black terminal directly to the negative terminal of the battery, but every set of directions on the subject says NOT to do this, and to connect to a ground instead. What gives? One more thing... This truck is new to me and there are a LOT of electronics hooked up already (lights, inverter, converter, CB, radio, etc.). I think that it was hooked up so that there is a 12-volt side that is (possibly) separate from the 24-volt side of the system. Just wanted to throw that out there in case it made a difference... Thanks in advance, and I appreciate your patience in answering such questions from an electrical neophyte such as myself! -Jon

[Jim LaGuardia]

I would bet the inverter is hard wired or a 12v circuit is tapped at the battery . First for the 24v charger + to + and - to - .
To find the draw use a test light, turn battery switch behind seat off, now remove the ground side battery cable. now put the test light connection to the 24v -(ground side)of battery and then touch tip of test light to chassis ground or ground cable. If it lights up, there is a draw.(edited)
Disconnect/turn off items one at a time till the light goes out, re configure your wiring to repair ground isolation circuit.
Everything must ground to the body. If you have a winch, do not run ground cable all the way to the battery, this will bypass the ground shut off key allowing power to flow.(ground it to the mounting) you can always upgrade the ground side cable of the switched circuit.

[Jimm391730]

All batteries CAN create hydrogen gas, even the "sealed" batteries. So any spark could ignite that gas. However, hydrogen is the lightest element and most of it rises and dissipates quickly, and most of the hydrogen production comes from charging (mostly OVER charging). As the last connection to be made will usually make some spark it is always recommended that the last connection be made to a chassis (ground or negative) point last, so the spark that is created will be away from the battery and any possibly gas that could be ignited.

So now you know why all instructions say to make the last connection to the chassis. In my experience, unless you just cooked the batteries by overcharging, there is very little chance of any gas generation so I personally am not too worried about connecting the charger clips directly to the battery terminals. However, I take no responsibility for your actions or inactions.

So if it was MY truck (and I do the same on mine) I would just open the battery door, pull out the tray, connect the negative battery charger clip to the negative battery terminal that has the wire that goes through the wall (not the terminal that has the wire that goes between the two batteries) and the positive 24V charger clip to the positive terminal of the other battery, and THEN plugh in the charger. This order should create the least amount of sparks. When the charging is completed, disconnect the AC power to the charger first, wait a minute, then disconnect the cables to the battery (again, this minimizes sparks, and gives any gas a chance to dissipate).

I would suggest turning the truck battery key off during charging, but there should be no harm if it is left on, either.

If there is any wires connecting to the short connection between batteries (at either end) and the truck does not have a battery equalizer, then the previous owner set you up for problems -- expect to replace batteries OFTEN (possibly onece a year or more). This may also be the reason for your battery drain, seperate from the abuse that the batteries get when power is removed from the middle 12V connection point. Get a 24V to 12V converter for the 12V loads and LEAVE THE CONNECTION BETWEEN BATTERIES ALONE!!!!

What happens is that the 12V loads drain the lower battery more than the upper battery, and since they are charged in SERIES, both get the same amount of charge -- this means that the lower battery never gets enough charge, and the upper battery gets OVERCHARGED just from driving around town. Eventually, both batteries fail.

While you can't stop the upper battery from becoming overcharged, frequent independent charging of each battery (each with it's own 12V charger) will help to prevent the lower, more undercharged battery from getting too undercharged. But the timing of "frequent" depends on the parasitic loads and amount of unbalance in the battery loads; this could be as often as every week.

Good luck,

[Jon_Gilbart]

After posting my initial post, I took my voltmeter out to run a few tests. Here's what I came up with:

Voltmeter from x to y-----Disconnect-----Charger-----Voltage
1 to 4-----------------------OFF-------------OFF---------29.5
1 to 2-----------------------OFF-------------OFF---------14.1
3 to 4-----------------------OFF-------------OFF---------15.7

1 to 4-----------------------ON-------------OFF---------30.4
1 to 2-----------------------ON-------------OFF---------14.5
3 to 4-----------------------ON-------------OFF---------16.1

1 to 4-----------------------OFF-------------ON---------39.0
1 to 2-----------------------OFF-------------ON---------18.1
3 to 4-----------------------OFF-------------ON---------22.1

1 to 4-----------------------ON-------------ON---------41.4
1 to 2-----------------------ON-------------ON---------18.9
3 to 4-----------------------ON-------------ON---------22.9

#1 is the positive terminal on the upper (leftmost) battery
#2 is the negative terminal on the upper (leftmost) battery
#3 is the positive terminal on the lower (rightmost) battery
#4 is the negative terminal on the lower (rightmost) battery

As I sit here typing this, I'm starting to think that this is pretty ridiculous, but anyways, I figured that I would give it a try. All I came up with from the data is that the upper battery is consistently low in all situations. I'm sure there's more info there to be had by someone who understands electrical systems more than I (that's pretty much everyone!), but since I don't really know what NORMAL is, that's about all I got out of it. Good to get a baseline, I guess, and hopefully this will help me as I do more tests in the future. The end result of all this was that I took the Pinz to Advance Auto (after jump starting it), had them test both of my red top batteries, and they said that the upper battery needed to be replaced. I put it in, and will see what happens tomorrow. I definately will try the tests you guys recommended when I get more time (I'm in the process of opening up a 2nd and 3rd dental office, so time is short these days!). Thanks for all the advice! -Jon

[Jon_Gilbart]

Here's what I have done since I last posted: I put a new optima red top UPPER battery in, and drove home. The next day, it wouldn't start again. I tested the voltage under different conditons, including when the starter button was being pushed (b/c someone else had a problem where voltage dropped to 0 when starter button was pushed), and the only thing that stands out to me is that voltage across the batteries while the Pinzgauer is running is 44 volts!!! I read in one of Jimm391730's previous posts that the expected voltage across BOTH batteries while the Pinz is running should be around 24 volts or so. As such, it appears that I am getting about twice what is normal! I am thinking that whatever is causing this problem is killing my batteries! What is counterintuitive to me is that if I have MORE voltage than I need from the batteries, why are the lights dim in the dash when I switch it on and why don't I have enough juice to start the Pinz? As suggested, I disconnected the negative battery cable from LOWER battery and connected a test light between the negative cable return to the pinz and the negative battery terminal. It lit while the battery disconnect behind the driver seat was connected and went out when the battery disconnect was removed. So no parasitic draw, correct? -Jon

[Jim LaGuardia]

Start with a voltage regulator, charge voltage should never exceed 28.8v .
I would also check the Molex connector.
E.I should have regulators in stock.

[Jon_Gilbart]

Update on my electrical problems w/ new questions...

I replaced the voltage regulator w/ a new one from Expedition Imports--easy job! Voltage across both batteries when the Pinz is running is 32 volts or so (still a little high [???] but WAY better than the 60-some-odd volts I was getting earlier!). The voltage across both batteries is about 26-27 volts when the Pinz is NOT running. I started her once after putting in the new voltage regulator to take the new voltage measurements--no problem. I tried to start her again later--no luck. The voltage across both batteries is still around 26-27 volts, but when I turn on the key, the charging system light in the dash is pretty dim, and then goes out when completely once I push the start button next to the key. She won't even turn over without a jumpstart, even though the voltage appears fine. I'm thinking that there is a problem with the starter or alternator, or a short somewhere, but I really don't have much of a clue. In trying to locate the problem, I started by unhooking the EXTRA (???) wires that are connected to the battery. I am assuming that there should be just one connection to the upper battery positive terminal, then a connection from the upper negative to the lower positive terminal, then a connection from the lower negative to ground somewhere--is this correct? I had an extra (???) wire run to the upper positive and the lower negative. There are a whole lot of things that are wired into my Pinz, and I figured it could only serve to help by elimininating as much of the extra stuff as possible to solve my electrical dilemma. I've been trying the decipher the "ENGLISH" in the repair manual, but between the oddly-phrased "ENGLISH" and my poor command of electrical troubleshooting, I'm not getting very far. I still haven't checked the molex plug yet (as was previously suggested) beyond just looking at the portion of the plug that is outside of the black metal cage that surrounds much of the engine (mainly b/c I need to read up on exactly HOW to check the molex plug), but in light of this new information, are we still thinking that it's the molex connector? Or perhaps a short somewhere? What about the starter? Something else? I guess I will try to make a 24-volt 3 watt test light (or somthing like that--whatever it says in the repair manual, which I don't have on me at this moment). This will be my first attempt at tracking down an electrical gremlin, so any further help w/ troubleshooting is GREATLY appreciated! Thanks. -Jon

[undysworld]

I still haven't checked the molex plug yet (as was previously suggested)

are we still thinking that it's the molex connector? Or perhaps a short somewhere? What about the starter? Something else?

The Molex connector has a reputation for developing problems. It's just a connector for several wires. Those wires connect to your alternator. Look for loose or broken connections.

Jim L is one of the more knowledgeable contributors on this forum. I he's suggested you check the Molex connector, I'd do that before looking elsewhere, since your 32v at charge is higher than the 28.8 he quoted you.

Maybe you've got a second problem with the start circuit. If you've got 26-27 volts at the batteries now, what is the voltage across them when you try to start it? Does it drop? Do you have 24 v at the starter when you turn the key? I suspect you've either got a problem with getting the 24v to the starter, or a bad ground. IIRC, starter grounds are a common issue too.

[Jimm391730]

Jon, I suspect that your batteries are toast. They should not be 32 volts when the truck is running (especially with a new voltage regulator). Bad batteries will not have a consistent voltage; it can be higher or lower than expected.

I am assuming that there should be just one connection to the upper battery positive terminal, then a connection from the upper negative to the lower positive terminal, then a connection from the lower negative to ground somewhere--is this correct?

Yup.

but when I turn on the key, the charging system light in the dash is pretty dim, and then goes out when completely once I push the start button

If the batteries are shot, they have no energy. The drain from the dash light and ignition system when the key is on is probably dropping the battery voltages way down, and pushing the starter button pulls the voltage down to zero. This happens with one or more bad battery or bad wiring and/or connections. Start by putting the voltmeter on one of the two batteries and monitor that voltage when you turn on the key, and when you push the starter button. A good battery will start at 12-13 volts and not drop hardly at all when the key is turned on, and drop up to 2 volts when the starter button is pressed. Do the same for the other battery. I'm guessing that one or both are going to drop to just a volt or two as the starter button is pressed; replace that battery.

If both batteries read good per the above, start following the wiring from them -- the positive cable goes to the starter, and if you put the voltmeter from the + battery terminal to the starter bolt (long stretch, I know, but worth the effort) you should see almost zero volts between the ends when the starter button is pressed. Anything more than a 1/2 volt or so means bad wiring or connections. Next, measure the voltage between the negative battery terminal and the truck chassis. Again, a good truck will have minimal voltage drop. This is where many people find problems, as this connection goes through the battery key and bypass relay. If you measure a volt or more then there are problems there. Keep narrowing your search until you find where you get a large voltage drop and this will be your problem.

One or more batteries, and/or one or more wiring/connections is a 99% certainty of being your problem.

[Jimm391730]

I'm guessing that one or both are going to drop to just a volt or two as the starter button is pressed; replace that battery.

I meant to say to replace any battery that drops MORE than just a volt or two. I hope you didn't go through twenty good batteries already...