don_a
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Re: PD9245C-14.8
Thanks - you inspired me to work to lower the 14.8V output of my "C" model to get it back down to the lower stock boost voltage of 14.4 which is going to serve as my new lithium bulk charge source (hopefully working as well as the 14.8 did for my GC2s). Note here that I only use the PD for boost alone powered by a wind-up timer while running the genset. I initially worked to design a solution that had variable output by installing the pot on the rear and running a very thin shielded cable from the 50K POT to near the DC side where the microprocessors and DC output was provided. (Back of unit faces toward me in implementation.) In my mind it was of course a work of art-work until I discovered the unit goes into bad oscillation unless the resistor is soldered right on the board. Then I wasted another half day before realizing that there is so much RFI pouring out of the device open case that it was making my digital multi meter go insane each time I tested the feature I had added. Turns out I should have put the case back on and tested it but after working on it about 8 hours, I got fed up with the constant oscillation (makes a squealing sound in the transformer) that I just soldered the stock value 34K resistor back to the board and at 14.37 would just call it a wrap. I was quite confident I had ruined the power supply because my DVOM was scaling all over the place even with the resistor soldered right to the board. Then I simply put the PD case back on with the stock resistor and it was stable. Settled right back down with the case on. So will a pot work on this? Answer is that's extremely doubtful it would work even if testing it with the case closed and this is due to the large amount of RFI swirling around inside that case. On super close inspection, I see they even have a ground "tab" on the PCB running under that resistor which I assume is a late-add engineering change to try to keep some of that RFI out of the microprocessor pin which causes the oscillation you hear as the unit is powered down. Now I must warn anyone who attempts this, if you are old-school and even if you have modern equipment, these components are all micro, for example the resistor in question is smaller than the tip of a fountain pen and you can destroy the board unless you have either a magnifying board camera or jeweler's glasses on. It's not easy and good chance there are only about 3 resistor swaps opportunities before you have destroyed the board. I got extremely lucky but for others, I don't recommend attempting this unless you have experience working with boards with micro components and have jewelers tools and a tiny soldering iron. Anyway thanks _ _ _ I'm "set" again until something else goes wrong.1KViews0likes0CommentsRe: PD9245C-14.8
KJINTF wrote: It's a simple modification to increase boost voltage from 14.4 to 14.8 or almost anything you desire. Pin #5 of the micro controller is connected to a 32.4KOhm resister - drop the value by several hundred Ohms and the Boost increases - Simply solder a 60KOhm across the resister in question. Any chance you are still around here KJINTF? I have a PD9270 with the solid 14.8V boost modification from Randy and I want to lower that to 14.4V. I used the pendant for generator boost charging only and this is too hot for my new batts. I've looked over the board and the microprocessor (assuming that's it, where the pendant wires run into it) and I don't see any non-factory looking board-work and I don't see any kind of pin-out on the little black IC that is not obviously labeled on the main board. I know it's a decade ago but do you have any photos or could I email you a photo of mine and you comment on what resistor I need to alter? Thanks!1KViews0likes0CommentsRe: MegaWatt S-400 as boost charger up in smoke
I am currently parked in Antigua Guatemala and would be happy to send upon my return which will be several months from now. I am driving a 2006 Navion by Winnebago with the stock generator that will power the 18A HVAC with no problem. I have a combo volt/amp meter on my power source after the transfer unit which shows the characteristics of the power I have switched the transfer unit to. The voltage from the generator was at 120VAC out of the generator and I didn't make note of the amp reading. No other appliance other than the Norcold 6xx was running off the generator. I have two 4/0 welding cables run 10' from the two Costco GC2's in series that run into my louvered cabinet that has to two solid copper bus bars mounted there where the solar, a 2000W inverter (no, it wasn't on and is seldom) and the 2 solar controllers are tied into that bus as well to produce 430 watts. On this day it was heavy cloud cover after 3 days. There is a 500A shunt from my battery monitor on the negative terminal of the two series battery bank and on the positive terminal has a 300A AGC fuse in line. The wire going from the bus bars to the MegaWatt is two three foot long 4AWG stranded battery cables with the ends fanned out into 3 smaller twists that are covered in heat shrink and 3 spade connectors soldered on the end of the 4AWG cables to mount to the 3 Megawatt terminals for each DC output post . The Megawatt is in the same cabinet with a solid louvered door that is about two cubic feet and the door was open during the charging session.257Views0likes0CommentsMegaWatt S-400 as boost charger up in smoke
It looks like this discussion is archived and can't be reopened (another example of some topics being locked up that are best kept open because the solution remains relevant), but that's another topic for another day. Today I want to warn anyone not to make the same mistake I did by following an old post here, and to supply the details to hopefully prevent someone else from repeating it and burning up a relatively expensive device. I was following a philosophy stated here of using a Megawatt S-400, setting it to 14.8V and attempting to change a battery while using a wind up timer to energize the MegaWatt for a short amount of time. I had two Costco GC2's in series in my coach that had discharged to about 85% according to my battery monitor when I started the generator. I then twisted the timer for 40 minutes and began to read while I waited. I noticed 36A charge reading right off the bat on the battery monitor so I decided to check the voltage on the actual battery terminals to see if anything was awry. (I had set the MegaWatt to 14.8V via the adjustment pot reading it with no load.) The voltage on the battery terminals read 14.3V which . After about 15 minutes of rapid-charging I smelled something a little odd and by 30 minutes the power supply had shorted out internally and tripped the GFI. Calling the manufacturer, the support person said that the charger would only produce 30A long term and that I burnt it up by not following the suggested amperage limitation. (There is no built in regulator for the device he stated.) Anyway I have a boat anchor now so other people who want to build a single stage "boost only" charger from previous suggestions in this forum should keep this in mind if your 14.8V boost supply is rated at under 30A in reality as this one is (apparently).958Views0likes4CommentsUnethical deletion of thread: BLM campgrounds
The recent thread on the BLM campgrounds and all the history about the bill to sell them off - yes all of the information here was deleted with no warning. There were many people who contributed, many people who made a great discussion. Additionally there were no political party lines drawn and only positive ideas about campers wanting to know what could be done to keep the BLM campgrounds from being sold. Why was the entire thread removed from here without warning or without reason? If the potential loss of the free or moderately priced BLM campgrounds is not a topic to be included or of concern of any camper, particularly dealing with the topic of "RV Parks, Campgrounds and Attractions", then please tell me what topic a BLM campground or its potential loss would be a subject of then?793Views0likes1Comment
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