Getting to that magic 14.8 v with an RV Charge Controller

[Wet_Coast]

Hi all, there have been some really constructive discussions in a number of threads in the past couple of weeks regarding battery voltages.

The threads have a re-ocurring theme. Get your batteries to the magic 14.8 volts. While this can be done with a manual charger and a good eye, it's hard to do with the "automatic" charger controllers.. I wish I had found certain material before I coughed up for the PD9160!

I installed my Charge Wizard this morning and found in the super duper charging mode I am getting 14.36, not even 14.4v. Too bad the pessimistic engineers didn't go even a couple of decimal points higher to match their specs!

Is there any way to tweak, say a Progressive Dynamics or other manufactures charger that is "off warranty"?

The PD9160 seems to have some of the case pop riveted. Haven't looked too close as I thought I would ask the question before venturing forth myself. While folks say there may be a way to adjust things, there is no material on how to with the various controllers, RV or solar.

Regardless, my Tracer solar controller according to the spec sheet is supposed to 14.8v. What I am thinking until I can have my technology evolve, is rely on the PD9160 to get it at least to 14.37 and not 14.4 they claim and have the solar get it to 14.8v top it off after.

As well, I went through Handy Bob's material.
Handy Bob's Solar Blog. Unfortunately, he does not mention any under the hood stuff either. Boy, I would love to have a chat with him at the fire one evening!

So learned propeller heads, is there a easy way to adjust the PD chargers to get them to 14.8?

thanks

[Salvo]

Amusing!

There are quite a few people out there that are smarter than the PD EEs.

What's wrong with this picture?



After 240 min, the PD finally gets up to 14.4V. Current tapers from the get go.

14.8V spec

RJsfishin wrote:
If Voltage needed to be higher than 14,4, PD would have made it that way.
Are you all smarter than the PD engineers,....or just think you are.

[BFL13]

RJ, PD with its 14.4v is inadequate for Trojan batteries specified to require 14.8v (up from previous 14.6 spec a few years ago) So it is not forum members who think they are smarter than PD engineers. it is Forum members who actually believe the battery makers like Trojan know what their batteries need.

Salvo, there is a typo in your good post above on the Iota. The absorption voltage is 14.2v. The PowerMax drops to 13.6v absorption.
ISTR the Iota does not actually get the batteries to 14.8, but drops to 14.2 15 minutes after getting the batteries to 14.6 (IQ4 description)

Only some PowerMax models have 14.8v, but their adjustable voltage models can do 14.8 of course and even higher.

OP, you can do occasional 14.8 or higher to goose the batts by using the solar with the controller by-passed. It is then like using a manual charger where you have to be there to shut it off when the batteries reach the desired voltage (or else the voltage just keeps rising until the liquid spills out the caps)

The Tracer's profile is fine for daily camping, but you will still need to do the occasional overcharge to 15+ volts as recommended by many battery charging blurbs, eg

http://pdf.wholesalesolar.com/battery-folder/charging_instruction_2011_2.pdf

[MEXICOWANDERER]

If'n the folks dint want 20,000,000 " indocemented" folks wanderin' round they wudda done sumthin 'bout it....great logic.

Charge your batteries to 14.8 volts. Stop the charge. Let the batteries sit for 2-3 hours. Then check state of charge with a hydrometer. Whatever you see will be reality in action. Totally BS PROOF.

[RJsfishin]

If Voltage needed to be higher than 14,4, PD would have made it that way.
Are you all smarter than the PD engineers,....or just think you are.
And if you want higher voltage, both my little schumachers go to 15.4 for several hrs before float.
My bigger Schumacher goes to 16+ volts before dropping stage.
My tender only goes to 14.4.
Both my stanleys only go to 13.8, then drop to 12.9.
They all have different ideas, w/ PD being the very best, not IMO, FACT !!

[Salvo]

Yes, some converters can get to 14.8V. The Boondocker and Iota are two converters that output rated current until the absorption voltage is reached. Iota absorption is at 14.8V.

Before you do anything else, test the performance of the PD. Purchase a 200A panel meter like this:

200A panel meter

200A, 75mV shunt200A, 75mV shunt

Discharge battery to about 50%. Start converter and measure Vbat and charging current. If you have another meter then measure voltage directly at the output of the PD. If you can assemble all meters in one location then you can record a video of the measurements. Otherwise record measurements with a time base. First record every minute (for first 5 min), then every 5 min (until the half hour mark), then every 15 min.

Graph data in a x-y scattery Excel file.

Here's the 55A Iota charging 2 GC2.

Wet Coast wrote:
you don't think the 14.8 can be achieved with the newer solid state technology chargers?

[Wet_Coast]

Was this with a AGM battery? They have a lower internal resistance and therefore the PD does a better job with them. You also need big & short battery cables.

4 Lead acid 240 ah 6v golf cart batteries

1/0 welding cable to everything

MEXICOWANDERER: you don't think the 14.8 can be achieved with the newer solid state technology chargers?

[Salvo]

Was this with a AGM battery? They have a lower internal resistance and therefore the PD does a better job with them. You also need big & short battery cables.

landyacht318 wrote:

So it could not hold 45 amps, but 39 is fairly close and it was constant current 39 amps until battery voltage approached 14.4.

[time2roll]

While IMO 14.4 volts is plenty.... 200 watts of solar to finish the charging at 14.8 volts would be an option.
Need to spend a few $$ on a programmable controller.

[MEXICOWANDERER]

Lesee, since the 10SI Delco alternator was introduced some forty years ago with the 1116387 voltage regulator, 14.4 volts was the temperature compensated point of regulation. The the 15 SI alternator was introduced with the 1116405 voltage regulator set a T/C 15.0 volts.

Until someone in the industry gets off their dead A$$ and introduces a user adjustable authentic converter we shall continue to see the Wizard of Oz, Toto, Looney Tunes, and Car 54 Where Are You, bad charger jokes on the shelves.

Can the BOONDOCKER get to 14.8 volts, and stay there for long enough to raise the battery acid specific gravity within reasonable distance of seeing 95% state of charge? I do not know. I do know there are seven hundred to three thousand dollar chargers that can do it but they are almost always transformer based not PWM. Is there a converter out there that can do this? Fourteen point eight volts. Wit some free time investigate the TIME needed to fully recharge a 50% depleted battery with various voltages. I do not like fifteen volts! It overheats antimonial plate grids too easily when used continually. For a 20-minute top charge fine. For a few hours, no.

The SOLE converter I am aware of that works according to user specs in the quarter-century old Trace 2500 SB inverter charger.

But who knows maybe there is something out there that can work as good. I'm sure open to suggestions about this.

[Wet_Coast]

The OP should verify charging current. Don't need to charge for hours by gen if it's not at rated current.

The only time I have seen it do a "Big" charge was while camping on the long weekend when I used it for the first time; without the charge wizard. I had the batts down to about 12.35.

Ran the genset and it started at 32 amps @13.something volts and it backed off to about 2 amps and 12.7v after about 2 1/2 hours. At that point, I killed the genset and let the solar top it off. I like my quiet so as long as I have sun, I like to finish that method.

I will have my electronics team at work look under the hood and start "testing" once camping season is finished. Thanks, all input is appreciated! Keep it coming.

[landyacht318]

The pd9245 I tested maxed out at 46.2 amps, and this tapered to 39.x amps once the unit heated up about 10 minutes later. It would hold 39 amps until the battery voltage approached 14.4 and then taper.

So it could not hold 45 amps, but 39 is fairly close and it was constant current 39 amps until battery voltage approached 14.4.

[Salvo]

Has the PD been redesigned? I haven't seen any PD that goes into constant current mode while in boost.

Constant current mode means the converter outputs rated current until converter voltage climbs to 14.4V (rated voltage). Only at this point in time current tapers.

The PD's I've seen slowly (perhaps in 1 to 2 hours) creep to 14.4V. The converter never outputs rated current for any duration.

The OP should verify charging current. Don't need to charge for hours by gen if it's not at rated current.

[landyacht318]

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28378659.cfm

Looks like PD needs better quality resistors. The PD9245 I played with was 14.56v boost, 13.73v normal, and 13.34v when in storage modes

[1492]

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