2005 Itasca Sunnova Parallax Charger... Failure?

2005 Winnie Itasca Sunnova, live full-time. I replaced the two 12v coach batteries abt. two months ago (Duracell), when in abt. a 2 day process the indoor lights were dimming. Cleaned up the battery wires and reconnected the 2-stage Parallax power converter (not the first time doing this, sometimes a simple ?kick? on the converter box got things running again!) but THIS time I wasn?t so lucky, everything down to the low-current devices failed (thermostats). So I had a hair-brained idea: Being a radio amateur, I have a rarely used Astron RS-35a power supply (rated 13.8v, 26 amps continuous, 35 ICS amps 50% duty cycle). I completely pulled the batteries out of the system (bypassed), wired the Astron in place of the Parallax. Viola! DC ?life support? was back on (air thermostat controls, fridge thermostat controls, lights), with the understanding that this would have a lack of ?backup? should AC shore fail.

Now we have a need for the propane furnace, however, and that appliance sucks CURRENT (blower,mostly). I consulted with two persons, they both said that the Astron SHOULD be fine (IF I?m running nothing else DC!). Got back from vacationing, and hit the AC for propane heat. Started fine, ignited fine, but after 15-20 minutes, the Astron Power supply?s rear heat sink and 4 transistors were getting a bit warm to the touch, so I shut the heat off. Ran it again briefly this morning, with eventually the same warm result. Just as a test, I pulled the Astron out, and reinstalled the Parallax (batteries still removed from the loop, but the Parallax is rated 45 amps alone). Still nothing from it, even for powering low-current thermostat controls on its own (is it safe to say that the Parallax is shot?)

I take it that, from the fact that the Parallax won?t power the AC thermostat/fridge control on its own (but the Astron will), I can definitely say that the Parallax is ?dead?, and in need of replacement, no? By bypassing the batteries and going direct from both power supplies (one charger/PS at a time, of course) to the bus bars under the cooking range (nearby where the Parallax charger is/was originally situated, not quite under the sink), with only the Astron working ?relatively? okay (as long as I don?t overtax it, current-wise), then I can deduce that there are no ciruit breaker/fuses/battery solenoid switch concerns? Could the new batteries have contributed to any of this failure (in 2 months)? I metered (VOM) the Parallax removed from it all, usually reading zero, rarely about 8-9, but never more. Does it definately sound like I need a new charger/p.s.?

Yes! Also, if you set the power supply output correctly (~13.3V) there is no reason to remove the batteries. It should charge them just fine albeit slowly at that Voltage.

Ernie

The furnace fan draws about 5-6 amps, so that alone should not tax the Astron.  The warmth is either normal or something else drawing power. In any case, get a new converter/charger. 

Could be that one of your new batteries is bad (internally shorted or a weak cell) and drawing amps simply because it's voltage is low relative to the rest of the system. It's rare, but sometimes faulty batteries escape the battery factory.

reply to ernie n tara: So I do need a new charger/converter. I take it that charger/converters... wired in parallel w/ the batteries, as it appears... recharges the batteries @ different rates, depending on its stage (bulk, absorption, float, etc... these are different VOLTAGE? rates of recharge. Yet for, say, the lights to remain reasonably bright, THEY still need the same volts, no?) And REGARDLESS of what stage that the BATTERIES are recharging from the charger/converter, the charger/converter STILL provides enough power (volts and/or current) for all of the DC items (furnace, air thermostats, lights staying bright), IN ADDITION TO properly recharging the batts as two different, yet SIMULTANEOUS functions?

I live in this permanently w/o moving it, could I simply bypass the batteries (and the hassle there) ALTOGETHER (w/ a new converter/charger rated @the same 45 amps as the Parallax was)? Wouldn?t that give enough current on its own?

to wizard: we got these wet cells @ a battery store, mostly sells Duracell, series 24 (like the old batts), MCA 615, CCA 500, 150 mins @ 23A. The kid @ the store claimed that he was selling a sealed (something ?other than? wet cell) batt, until I demonstrated the removable ?pop tops? for water. Any way to test batts w/o hygrometer or anything? Guess that I could take it back to the store.

Something unusual w/ Astron... when i turn on wife?s Kurig coffee machine, the Astron makes a periodic vibration noise while the Kurig is heating/serving... like transformer or capacitor in Astron being ?put through its paces? sometimes. Suprising since the Kurig is a seperate AC appliance.

Some converter chargers are rated as converters and power supplies (IOTA). When connected in parallel with the batteries the converter is providing charging current for the batteries and what ever the coach is requiring for lights and etc.

I would get at least a 55 amp replacement, Progressive Dynamics or IOTA

I would also get the Charge Wizard to be able to over ride the automatic function

John Hilley said:

Some converter chargers are rated as converters and power supplies (IOTA). When connected in parallel with the batteries the converter is providing charging current for the batteries and what ever the coach is requiring for lights and etc.

I would get at least a 55 amp replacement, Progressive Dynamics or IOTA

I would also get the Charge Wizard to be able to over ride the automatic function

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So I take it, John, that I could go to a slightly larger amperage PS/Charger, w/o any concerns of supplying too much to the number or kind of paralleled batts (two batts parallel, in this instance). Would I have to increase wire size between a larger current charger/PS and the DC distribution bus bar, etc?

I looked at both of those brands of charger/converters, and I figure that either brand with the addition of their respective ‘Wizard’ indicator/controller would be good, in one way or two (some only as indicatiors [Iota], some as indicators and override [PD]). Being a rookie, however, I have to ask: Under what situation would/should I feel the need to MANUALLY ‘override’ between charge modes (bulk, absorption, float)? I mean, the optional ‘Wizards’ allow the charger to do this on their own, right?

Presently leaning to the 45amp Progressive Dynamics (or slightly more current model, maybe),w/ wizard.

Gary RV_Wizard said:

Could be that one of your new batteries is bad (internally shorted or a weak cell) and drawing amps simply because it's voltage is low relative to the rest of the system. It's rare, but sometimes faulty batteries escape the battery factory.

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Exactly, Gary. That?s why if I know for certain that I can always leave batteries OUT of the loop (as long as the RV is not mobile) then i?d do away with those pains altogether. Could any, or only certain brands/kinds of charger/PSs be done this way?

Leaving them out is likely ok for most chargers but be aware that the batteries serve to filter the charger output. Also, if you replace the battrries again you should know you gave the wrong type for house batteries. Yours are starting batteries best suited for the chassis battery. House batteries will be deep cell andrated in Amp hours rather than starting current.

Ernie

...if I know for certain that I can always leave batteries OUT of the loop (as long as the RV is not mobile) then i?d do away with those pains altogether. Could any, or only certain brands/kinds of charger/PSs be done this way?

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I don't know of any the currently available RV converter/chargers that require having a battery in the loop to operate properly. That has not been the case since the early 90's. There is still a potential power quality concern, but the digital electronic type of converter does not seem to produce the ripple that was so prevalent in the old transformer-driven units.  I'm sure the specifics depend on the quality of the circuit board design, but in my opinion it is not something you need worry about.

...I could go to a slightly larger amperage PS/Charger, w/o any concerns of supplying too much to the number or kind of paralleled batts (two batts parallel, in this instance). Would I have to increase wire size between a larger current charger/PS and the DC distribution bus bar, etc?

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Having a larger supply doesn't push more amps into the batteries - it just makes them available. As for wire size, that cannot be answered without knowing what you now have. Looking back in this topic, I don't see even the present Parallax model info, but the Sunova brochure says it has a 45A converter/charger.  Usually, the wire to the bus and battery are adequate for at least a modest increase. Some power systems have a circuit breaker in a separate battery charge controller, though, and that might be a 50A breaker. Not sure what you have in your rig.

Under what situation would/should I feel the need to MANUALLY ?override? between charge modes (bulk, absorption, float)? I mean, the optional ?Wizards? allow the charger to do this on their own, right?

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No need to do any manual switching, in my opinion.  Some people like to tinker, but the wizard devices do a fine job on their own.

Gary RV_Wizard said:

I don't know of any the currently available RV converter/chargers that require having a battery in the loop to operate properly. That has not been the case since the early 90's. There is still a potential power quality concern, but the digital electronic type of converter does not seem to produce the ripple that was so prevalent in the old transformer-driven units.  I'm sure the specifics depend on the quality of the circuit board design, but in my opinion it is not something you need worry about.

Having a larger supply doesn't push more amps into the batteries - it just makes them available. As for wire size, that cannot be answered without knowing what you now have. Looking back in this topic, I don't see even the present Parallax model info, but the Sunova brochure says it has a 45A converter/charger.  Usually, the wire to the bus and battery are adequate for at least a modest increase. Some power systems have a circuit breaker in a separate battery charge controller, though, and that might be a 50A breaker. Not sure what you have in your rig.

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Not sure of any internal 50 amp breaker, but what I DO know that might be relevant, the RV camp site that we live at has both 30 amp and 50 amp service spots, and we've always used the 30 amp w/ no problems (on the AC/ circuit breaker/ outside box, 'supply' side of things). The current bar graph indicator in the indoor hall only goes to 30 amps (the 'thing' we use to regulate our own total AC current consumption, i.e., no microwave/convection with BOTH air conditioners on simultaneously). Are you suggesting that a higher current breaker may somehow exist FOLLOWING AFTER the outside, lower current (30 amp) one? I dunno...

Ernie n Tara said:

Also, if you replace the battrries again you should know you gave the wrong type for house batteries. Yours are starting batteries best suited for the chassis battery. House batteries will be deep cell andrated in Amp hours rather than starting current.


Ernie

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You mean, when I replace them again! That kid at that battery store probably fooled me in his 'cross-reference' book... if he actually COULD read... probably should've stayed w/ the exact model of Interstate batteries! Regardless, both of those OLD Interstates that we first replaced where sulfating? (crystalized dry white powder) on the outside, around the braces and contacts (AFTER 5 YEARS CONTINUOUS USE), until they got warm on the sides of them (one batt at a time) and I finally got them out of there (the second batt... left alone after removing the first... was gassing ! Darned right I removed 'em!

Can't say that any lack of purified water was at fault with the Interstates, my wife made me check them for that  RELIGIOUSLY by the month!

So basically I was given Duracell car batts, no? Still have warranty on them, maybe I can exchange them for some correct ones (or my money back, toward buying the correct ones somewhere else?)  RIIIIGHT!

We've had several good battery discussions in this Winnie board (and elsewhere in the forum) so search around - you can get a real good education from the knowledgeable folks here. Know what you are shopping for or suffer the consequences.

My rules of thumb for batteries, starting or house: Replace at three to five years regardless unless you use premium deep cycle batteries for the house. Starting batteries get replaced on my coach about every three years.

I consider premium deep cycle batteries to have AGM chemistry as opposed to the traditional flooded cell (wet.) I have three Lifeline AGM batteries for the house and they will easily last 7-10 years if not abused (abused: not deeply discharging them.) They will accept more charging current and have a very low self-discharge rate (a disconnected battery will slowly discharge due to internal resistance.)

rookieRV said:

Not sure of any internal 50 amp breaker, but what I DO know that might be relevant, the RV camp site that we live at has both 30 amp and 50 amp service spots, and we've always used the 30 amp w/ no problems (on the AC/ circuit breaker/ outside box, 'supply' side of things). The current bar graph indicator in the indoor hall only goes to 30 amps (the 'thing' we use to regulate our own total AC current consumption, i.e., no microwave/convection with BOTH air conditioners on simultaneously). Are you suggesting that a higher current breaker may somehow exist FOLLOWING AFTER the outside, lower current (30 amp) one? I dunno...

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You're confusing amperage at 12 volts versus amperage at 120 volts.  There's a 10:1 ratio between them, i.e. 50 amps at 12 volts is the same amount of power as 5 amps at 120 volts.

The 50 amp circuit breaker Gary mentioned is on the 12 volt side and may be just a little pillbox with two screw terminals coming out of the top.

rookieRV said:

Regardless, both of those OLD Interstates that we first replaced where sulfating? (crystalized dry white powder) on the outside, around the braces and contacts

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Sulfation refers to hard deposits forming on the battery's internal plates if it's left discharged, or the electrolyte level drops below the level of the plates, letting them dry out.  The hard sulfate deposits block the electrolyte from interacting with the plate underneath it, reducing the battery's capacity by making that portion of the plate inactive.

The white power on the external surfaces is corrosion and is a normal part of wet cell battery operation, caused by the acidic electrolyte mist coming out of the battery vents.  It can be neutralized by applying a solution of a baking soda dissolved in water to the affected areas.

Agree with John. Of our three motorhomes, this is the first with AGMs, and I love 'em! No one's ever accused me of being lazy, but it's sooo nice not to have to check water levels and specific gravity year after year. No more acid stains on the driveway, no more holes eaten through my shirts. Heck, even the battery terminals never needed cleaning.

I just replaced six of our eight house batteries two days ago, because I had begun to notice that they seemed to not be holding a charge as well as they used to. We boondock a lot, so our batteries get a pretty good workout. They lasted seven years, so no complaints (Well, maybe their price.)

Kev

From Progressive Dynamics FAQ on Charge Wizard

I dry camp most of the time and want to recharge my RV batteries using my generator the next day. Is there any way I can get a faster recharge rate?
Yes, all 9100 Series Converter/Chargers are equipped with our TCMS (Total Charge Management System) Connector to allow you to easily install our Charge Wizard. All 9200 Series Converter/Chargers are equipped with the TCMS / Charge Wizard built in. The Charge Wizard senses that your batteries are low and that you want to charge them fast therefore, it automatically increases the output voltage of the Converter/Charger to 14.4-volts and will return a 125-AH battery to 90% of full charge in 2-3 hours. Full charge is achieved in approximately 15 hours.

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Ernie n Tara said:

Also, if you replace the battrries again you should know you gave the wrong type for house batteries. Yours are starting batteries best suited for the chassis battery. House batteries will be deep cell andrated in Amp hours rather than starting current.

Ernie

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Here’s what I remember re: the batteries:

1- New Duracell pair (SL124MDC) matches the old Interstate pair in two ways: They’re both Group 24s, they both are printed ‘marine deep cycle’.

2- As I recall, the MCA and CCA ratings (for whatever those figures may be worth) were fairly close between the old Interstate and new Duracell battery pairs.

3- Each individual Duracell also had an additional rating marked on them: minutes @ 23 amps, 150 minutes.

So how bad does it sound?

They probably are comparable to what was originally in the motorhome. Depending on how you use the motorhome, they may be more than adequate. If you never dry camp, then they are fine. A group 27 or 29 would have more capacity.

Marine deep cycle batteries are not true deep cycle batteries.
Here's a good great article from our library to read:
http://www.rvforum.net/miscfiles/Choosing_right_battery.pdf

1- New Duracell pair (SL124MDC) matches the old Interstate pair in two ways: They?re both Group 24s, they both are printed ?marine deep cycle?.

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That's ok. Marine deep cycle" will not last as long as a true deep cycle (see my battery article cited above) but they are also much less expensive. Figure 3 years of use as typical.

2- As I recall, the MCA and CCA ratings (for whatever those figures may be worth) were fairly close between the old Interstate and new Duracell battery pairs.

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Neither MCA nor CCA are relevant to deep cycle performance. They are measurements of engine cranking capability only. The numbers you are concerned about at RC and AH.

3- Each individual Duracell also had an additional rating marked on them: minutes @ 23 amps, 150 minutes.

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That's the deep cycle rating, known as Reserve Capacity. Learn more about RC and AH (amp-hours) at http://all-about-lead-acid-batteries.capnfatz.com/all-about-lead-acid-batteries/lead-acid-battery-fundamentals/what-is-reserve-capacity/

Okay, not to beat on a dead horse, but I found it! the original Interstate batteries running with the Parallax 45 amp, 2 stage charger/converter for the last five years were SRM-24s, 550 CCAs ea., 690 MCAs ea., marine deep cycle group 24s.

New batteries are (were?) Duracell SL124MDC (group 24s), 500 CCAs ea., 615 MCAs ea., 150 minutes @ 23 amps ea., marine deep cycle group 24s (so, yes, they do sound like comparable battery types) The last VOM reading today on the Duracells (direct to batts, all else removed): 11.24 volts.

Does it sound like a new charger would do fine with the present status of the new batt set, or should I bring the batts back to the retailer for testing/charging/replacement while I’m waiting for the new charger/converter to arrive?

As maintenence-free as the other battery types seem, we live here, full-time, on the ‘cheap’. No dry camping/boondocking ever, only my wife that nags me to check the batt water levels every month! But, hey, the old pair lasted FIVE YEARS!