Another question on Converter sizes

[rtate]

There is another active thread regarding converter sizes, but I get lost in the wealth of detail offered here. I have a simple question: I have a PD 9200 , 45 amp converter, two Trojan T105 batteries and a Honda 2000w generator.

With my setup, should I see a 14.4v boost charge if my batteries were discharged down to 11.5 volts while charging with the generator?

How about charging with shore power?

[Sam_Spade]

rtate wrote:

The converter is supossed to hit the battery in boost mode every 21 hours to desulphur the plates. I dont know if it is doing that.

That "feature" is WAY over-rated.
And it is totally unnecessary if you have AGM batteries.

[rtate]

Just received my pendant for my PD 9200.I am pretty happy with what I see now. It It will allow me to put the coverter into boost mode and I get a reading of 14.4v (or 14.6v, dont remember which) at the battery. So I am happy that my wiring is ample and my coverter is operating properly.

The only thing that bothers me is that it doesnt seem to go into boost mode automaticaly, but I can manually force it into boost.

The converter is supossed to hit the battery in boost mode every 21 hours to desulphur the plates. I dont know if it is doing that.

Any way , I am pretty happy with things now. If I am dry camping I can force it into boost mode when charging with the generator. If I am hooked up to shore power, I dont mind if it takes a little longer charge.

Thanks for all the help and information.

[full_mosey]

Bobbo wrote:

...
This thread, the OP is just wondering why he is not seeing the 14.4v at the battery when he STARTS charging.

The OP's charging current is to low. :?

In the case of the automobile alternator, the available current will greatly exceed the Amps used to start the vehicle. Starting will likely use <5% of the battery's AHs. The alternator's current is so much higher than the missing AHs, the bulk stage is nearly instant and you don't notice the Volts rising to the Absoprtion Voltage.

In the typical RV, the house charger's current is way below the missing AHs at the time charging is initiated. The bulk stage takes much longer to accumulate enough AHs into the battery and that is when the battery's Volts slowly rise to the Absorption Voltage.

HTH;
John

[time2roll]

rtate wrote:
Can I expect my t105s to go from 11v to 90% charge in a couple of hours?

11v is a bit over discharged unless that is under a moderately heavy load. Otherwise you are looking at closer to 4 hours.

If you really want to go fast you need a PD9280-14.8 converter mounted close to the battery with #4 wire.

[time2roll]

rtate wrote:
So after trying to understand what everyone has told me this is what I am planing to do . Since I am not able to get easy access to my converter, I will disconect the wires from the converter to the batterie and take a reading of the voltage coming from the converter If my converter is doing its job, I should see a voltage of 14.4v coming from the converter. If I do get 14.4v I will then upgrade the wire from the converter to the batteries. If I do that I will see the batteries reach 14.4 v when charging.

If I dont see the converter putting out 14.4v when disconected from the batteries, then I have a converter problem.

Does my take on this make sense?

No need to disconnect anything. Just plug in and monitor the battery voltage. When you see voltage rise above 14 you know all is well. Besides if the converter has no battery to charge it may just produce 13.6 volts.

[time2roll]

BFL13 wrote:

time2roll wrote:
To my knowledge based upon reading many posts... only the IOTA will produce full amp rating and full voltage rating at the same time.

Where in the Iota charging profile does it do that where you can see it? The converter is set to a voltage, but you don't see it unless it is disconnected or else when the battery is full and no other loads. Iota is set to 14.8, gets the battery to 14.6, waits 15 minutes (when the battery voltage rises to X) and then drops to 14.2V

Most (all?) converter specs (ratings) are at 13.6v, but they are supposed to be able to do full current-limited amps at that or at their boost settings.

PowerMax and other converter/chargers hold constant full amps at their boost settings too, but PDs seem not to according to most posters on here. A few have made their PDs come close to doing it by using very fat short wire to the battery.

Plenty of posts where IOTA puts rated amps on the battery all the way up to full 14.6/14.8 volts (at the converter). Yes once the voltage limit is met the amps taper off due to the battery chemistry. Yes as IOTA drops to 14.2 volts for absorption there again amps will be tapering due to battery chemistry.

Unlike PD where amps will fall off by 10 to 15 amps as the voltage rises into the 14 volt zone.

[Bobbo]

rtate wrote:
Can I expect my t105s to go from 11v to 90% charge in a couple of hours?

I think a couple of hours is extremely optimistic. I think 4 hours is a safer bet.

BFL13 wrote:
T-105s or any other battery should not be down to 11 volts! 50% is 12.1 volts.

A pair at 225 AH at 50% with a 45amp charger doing constant 45 will take about 85 minutes to get the batts to 75% , another 20 min to 80%, and another hour from 80-90. So total 50-90 will take about 3.4 hours. the 80-90 for an hour might not be worth the gen time, which is why many do 50-80s instead.

BFL13 is right on the money here. My batteries are a little smaller than 225 AH, but my wiring is a little smaller too. My 158 AH battery bank at 12.0v or 12.1v (50% SOC) takes right at 4 hours charging time over the 6g wire. I don't really know the final SOC, but I consider it done when the PD4645V drops its charge voltage from 14.4v to 13.6v. I call it 90% SOC, but that is an assumption on my part. I have never let it charge to that point then let the surface charge go to get a reading.

BTW, I am the OP on the other thread, the one where I was trying to decide if I wanted to upgrade from a 45 amp charger to a 55 amp charger. The solution was no. It would only save me about 20 minutes charge time, at best.

[wa8yxm]

Tom_M wrote:
There's no difference whether using generator or show power. Your converter will start in boost mode at 14.4 volts

I will second that the 9200 can not tell (in theory) the difference between shore and the Honda.

What is the difference? Voltage regulation is excellent in the Honda Inverter jobs. plus the waveform is PURE sine wave. Shore power is not nearly as good in either area.

[BFL13]

time2roll wrote:
Measured at the converter yes voltage should steadily climb to 14.4 volts. Under initial full output the PD9245 could be closer to 13.4 or even less. Voltage tends to sag a bit on the PD. You will never see full amp rating at 14.4 volts. Battery voltage on the terminals will be somewhat lower due to the voltage drop in the wire connection. As the amps taper into the 3rd and 4th hour the battery terminal voltage should be rising steadily to 14.4 volts.

To my knowledge based upon reading many posts... only the IOTA will produce full amp rating and full voltage rating at the same time.

Where in the Iota charging profile does it do that where you can see it? The converter is set to a voltage, but you don't see it unless it is disconnected or else when the battery is full and no other loads. Iota is set to 14.8, gets the battery to 14.6, waits 15 minutes (when the battery voltage rises to X) and then drops to 14.2V

Most (all?) converter specs (ratings) are at 13.6v, but they are supposed to be able to do full current-limited amps at that or at their boost settings.

PowerMax and other converter/chargers hold constant full amps at their boost settings too, but PDs seem not to according to most posters on here. A few have made their PDs come close to doing it by using very fat short wire to the battery.
-----------------

T-105s or any other battery should not be down to 11 volts! 50% is 12.1 volts.

A pair at 225 AH at 50% with a 45amp charger doing constant 45 will take about 85 minutes to get the batts to 75% , another 20 min to 80%, and another hour from 80-90. So total 50-90 will take about 3.4 hours. the 80-90 for an hour might not be worth the gen time, which is why many do 50-80s instead.

[Sam_Spade]

rtate wrote:
If I do that I will see the batteries reach 14.4 v when charging.

If I dont see the converter putting out 14.4v when disconected from the batteries, then I have a converter problem.

Does my take on this make sense?

While it might sound logical, it might not be TRUE.
It is HIGHLY unlikely that you have a loss of 1 volt or more in the cables. And if you can't get to the converter, how are you going to change the cables anyway.

The converters were not designed to operate with no battery load so what voltage you see with no batteries connected might not prove anything.

At least one person, besides me, has told you that some models will never go above about 13.5. Yours may be one of those.

[Sam_Spade]

Tom_M wrote:
Your converter will start in boost mode at 14.4 volts

My last one didn't. So I was pretty sure that they ALL don't.
Seems like his model might be one that doesn't.

[rtate]

Ok. The volt meter I have been taking reading from is measuring at the battery.I do have a digital hand held volt meter and hydrometer.

Can I expect my t105s to go from 11v to 90% charge in a couple of hours?

[MEXICOWANDERER]

OK in that case what is needed is to measure voltage at the terminals of the charger and compare it to the voltage at the batteries. There should -never- be a one volt difference at maximum charge amperage potential. The charger sees the higher voltage and reacts to it. Neat huh? One error causes a worse error.

This is the reason that cable size is so touchy. Even .2 volt makes less of, but still an error. Massive cables and mirror bright connectors are in order. Even with a pendant. Of course this is difference is especially critical when charge time is limited by generator use.

Hate to harp but without a handheld voltmeter and hydrometer verification, setting up a "pendant" smart charger system is 100% guesswork and assumption. Flying in a fog bank minus radar. For a total charger to battery amperage round trip of say twenty feet and charger size of 45 amps I would select 1 gauge cable.

Where a lot of folks are missing the boat with sizing of a converter is not deducting for hotel loads. A 45 ampere converter becomes a weenie if hotel loads are bleeding off 15 amperes. This is why a shunt an ammeter measuring nothing but the quantity of amps entering the battery is so important. 6 cells of golf car battery at 50% state of charge is going to take a l o n g time to charge at 30 amps. Jeezo at 14.4 volts it's too long, st 14.8 time needed will still drive a person nuts if a generator is in use. Remember the limited amperage.

When my Kubota is hammering two hours is maddening. Three hours is intolerable. I can add the Trace for 120 amps or the Lombardini for an additional 385 amps. Only a massive 32" Horton fan keeps it from turning into an oven in there.

If I was dealing with a brainless smart charger I would definitely run tattle tale wires (tiny) to a 5 digit volt gauge the told me what the charger terminals are at. Then compare the two voltages. Tattle tale versus smart charger reading at the battery terminal and separate panel meter for the charger output right at the charger teminals. Verification at the charger and another right at the battery posts. A 5 digit panel volt meter has a 3 volt full scale wire connection option that can display volt drop to 3.3333 resolution.

I dipped all of my 330 MCM battery terminal post into a lead solder pot to solder them. Meaning the tin coating was covered with a thick coating of lead which is acid proof. But not galena proof. A gob of anti corrosion compound seals them away from from oxygen.

Configured correctly a charging system should start out and remain trouble free for years and years.

[rtate]

Lots of good information here. My main concern is that my T105 batteries are properly charged and conditioned for the longest life. My second cocern is that when boondocking I get them up to 90% charge with my Honda 2000 generator as rapidly as possible.

So after trying to understand what everyone has told me this is what I am planing to do . Since I am not able to get easy access to my converter, I will disconect the wires from the converter to the batterie and take a reading of the voltage coming from the converter If my converter is doing its job, I should see a voltage of 14.4v coming from the converter. If I do get 14.4v I will then upgrade the wire from the converter to the batteries. If I do that I will see the batteries reach 14.4 v when charging.

If I dont see the converter putting out 14.4v when disconected from the batteries, then I have a converter problem.

Does my take on this make sense?