Another question on Converter sizes

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.

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?

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.

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?

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.

MEXICOWANDERER wrote:
This is losing contact with reality as far as GENERATOR run time. With shore power, who cares?

If I walk out to my toad and start it the much touted BOOST (or is it BOOOST?) voltage appears. Regulator alternator charging voltage. Does the charging system on the car sag to "regular" charging voltage of 13.6? Hell no.

Tens of thousands of RV batteries are destroyed every year because boondockers believe that converter manufacturers specify is gospel

What's gospel about their mantra is that they cannot be sued for purposely overcharging a battery.

This reminds me of California's banning of battery CHARGERS in favor of socialist inspired government mandate to undercharge batteries and a (what?) thirty or forty times charger failure rate (landfill) as being environmentally preferable. Oooooo a timer on the charger who wudda thought of that.

The only way to achieve rational battery life when BOONDOCKING is to know for sure the battery state-of-charge.

A 20-amps per 100 amp hour bank, solar system with a good grade of solar controller seems to be the only antidote to the fallacy of smart chargers via generator WHEN BOONDOCKING.

Mex, it is MY thread that is about charging with a generator, and I really appreciate your input. Between you and BFL13, I think I finally understand the answer. On mine, upping my charger from 45 amp to 55 amp might (maybe) shave about 20 minutes off of my 4 hour charge time.

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

This is losing contact with reality as far as GENERATOR run time. With shore power, who cares?

If I walk out to my toad and start it the much touted BOOST (or is it BOOOST?) voltage appears. Regulator alternator charging voltage. Does the charging system on the car sag to "regular" charging voltage of 13.6? Hell no.

Tens of thousands of RV batteries are destroyed every year because boondockers believe that converter manufacturers specify is gospel

What's gospel about their mantra is that they cannot be sued for purposely overcharging a battery.

This reminds me of California's banning of battery CHARGERS in favor of socialist inspired government mandate to undercharge batteries and a (what?) thirty or forty times charger failure rate (landfill) as being environmentally preferable. Oooooo a timer on the charger who wudda thought of that.

The only way to achieve rational battery life when BOONDOCKING is to know for sure the battery state-of-charge.

A 20-amps per 100 amp hour bank, solar system with a good grade of solar controller seems to be the only antidote to the fallacy of smart chargers via generator WHEN BOONDOCKING.

rtate wrote:
I dont recall seeing my voltage over 13.6 volts. I have a charge pendant on order so Ii will be able to force it into boost mode.

That's likely because it only goes into boost mode for short period after many hour. Progressive Website will have the specs to determine how long b4 it automatically goes into boost mode.

Tom_M wrote:
Your converter will apply 14.4 volts during boost, but your battery will pull that voltage down. As the battery charges the voltage will gradually ramp up. It should at some point reach 14.4 volts and continue charging until 90% charge has been reached.

This ^^^^^^^^^^^^^^^.

It took me a while to figure this out. I have a solar controller with a panel on the wall. The panel gives the amount of charge at the battery. When I had a 50% SOC battery, and plugged in, my PD4645V converter/charger was SUPPOSED to go into 14.4v boost mode. My monitor showed about 13.5v or 13.6v. Over a period of about 4 hours +/-, the voltage would creep up to 14.4v, slowly. Finally, I got a DVM out and checked the voltage at the converter/charger. It was 14.4v there all the time. It was only at the batteries that I was seeing less. The converter/charger was doing its thing, and the batteries pulled the charge down, until they finally get enough charge.

Let me give you an analogy. You have tires that need 80psi, but you only have 40psi in them. You get out your trusty air compressor with 125psi of pressure in the tank. You start airing up your tires. Your tire pressure doesn't jump to 125psi as soon as you connect the air hose. The tire pressure slowly rises from the 40psi to whatever you allow in over time.

The exact same thing is happening to your battery. You have 11.5v in the battery and hook up a 14.4v charger. The battery's charge, over time, rises from the 11.5v to 14.4v, slowly.

Your converter will apply 14.4 volts during boost, but your battery will pull that voltage down. As the battery charges the voltage will gradually ramp up. It should at some point reach 14.4 volts and continue charging until 90% charge has been reached.