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Wet_Coast's avatar
Wet_Coast
Explorer
Aug 22, 2015

Getting to that magic 14.8 v with an RV Charge Controller

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

28 Replies

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  • Salvo's avatar
    Salvo
    Explorer
    Aug 22, 2015
    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's avatar
    time2roll
    Nomad
    Aug 22, 2015
    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's avatar
    MEXICOWANDERER
    Explorer
    Aug 22, 2015
    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's avatar
    Wet_Coast
    Explorer
    Aug 22, 2015
    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's avatar
    landyacht318
    Explorer
    Aug 22, 2015
    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's avatar
    Salvo
    Explorer
    Aug 22, 2015
    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.

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