Does converter overcharge battery?

[CedarCreekWoody]

I have been leaving my 2016 Creekwood TT plugged into 20 amp circuit to keep the fridge cold. This means the converter is charging the battery too. Does it provide a constant trickle charge that could damage the battery or is it a smart charger that shuts off completly when not needed? I don't know the brand/model but most likely TCI or Dometic.
On a related note is it a good idea to keep the fridge running while the TT is just sitting at home?

[spock123]

I have always kept my refrigerator on, a good place to store beer. You have to keep a eye out on the battery because the converter/charger will boil the water out of the battery.


Sent from my iPhone using Forest River Forums

[lbrjet]

If you unplug for any length of time disconnect your battery or it will drain in a couple of weeks. I used to own an RV lot and we were plugged in from 04/01 to 10/31 each year. I checked the water level every few months and only had to add a little water a couple of times of three years.


2010 F250 5.4L 3.73
2011 Flagstaff 831FKBSS
Equal-i-zer 4pt 12K

[Jerry01]

Need to know the brand of converter to give an honest answer. Not all converters are created equal. I don't see a problem with keeping the fridge going as long as you are connected to shore power. Jerry


Sent from my iPhone using Forest River Forums

[WolfWhistle]

Even the original equipment converter / charger is fairly new, it should not overcharge your battery (batteries) if it is operating properly. Yes, the batteries will lose some electrolyte, but this is to be expected as Ibrjet experienced. Check them routinely and add distilled water as needed. I also recommend a good charger such as IOTA or Progressive with the IQ4 add-on. The main thing is to never let a battery go dead.

If I keep a fridge running, I keep the interior fan going as well as keep it filled... adult beverages work well for this

WW

[SeaDog]

The converter will supply the 12V for the frig without the batteries being connected. Not all converters will go into a float mode so some may overcharge the batteries. I keep my batteries disconnected via battery disconnect switch when I'm on Shore power. The converter like I said supplies all the 12V I need.

[bikendan]

My 10 year old WFCO has never overcharged my batteries(knock on wood).
and I keep it plugged in all the time.

[BandJCarm]

I keep plugged up to shore at home....... but am new, first week with this thing.

I think I'm going to leave batteries 'on' for a week or two and 'off' for a week or two while connected to shore. It is a trickle charger (i'm pretty sure!)..... that's how I do my onboard boat battery charger..........

[mike.t]

I'm plugged into a 30amp plug at home and always remove the negative terminal. Good chance it will cook your battery.

[pgandw]

The best way to know whether the battery is being overcharged is to get out a voltmeter.

After fully charging the battery, the converter should drop down into a trickle charge mode (approx 13.1V for most converters), which simply maintains the battery. According to the WFCO manual, WFCO converters (common standard equipment in RVs) are supposed to drop from 13.6V (normal charging) to 13.1V after 44 hours of near constant current.

The WFCO in my A-frame will not go into trickle mode after several weeks, and with only the propane/CO detector and the stereo on. It remains at 13.7 volts, which is too high for long term storage. So I will be installing a new converter. In the meantime, I disconnect the battery after fully charging for several days after a trip.

I'm disappointed because 1) I finally figured this out 2 months after the 2nd year of warranty expired, 2) it may have caused the failure of my initial set of 12V batteries (I had 2 Size 24, one went bad and took the other one with it after bad decisions on my part), 3) the A-Frame has a combination converter/electrical panel which means more rewiring than just replacing a converter. On the bright side, I will get a better converter that will charge my batteries faster, and I can clean up the wiring rat's nest (and lack of proper color codes) that came standard behind the converter.

just my experiences, yours may differ
Fred W
2014 Rockwood A122 A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

[CedarCreekWoody]

Mine drops to 13.18 so that us close. Still a bit high for long term.

[northstar1960]

When on shore power i keep my batteries disconnected . i do once a month use the inverter to watch tv a few evenings and then will put a charger on the batteries to bring them back up . just to keep them exercised

[boondocking]

No need to exercise the batteries, actually they will last longer the less times they are discharged.

[WolfWhistle]

Originally Posted by CedarCreekWoody

Mine drops to 13.18 so that us close. Still a bit high for long term.

Trimetric solar charger sometimes shows 13.2v, as does the Magnum inverter / charger. Both have temperature compensation, so I think this is normal and good.
WW

[WolfWhistle]

Originally Posted by pgandw

The best way to know whether the battery is being overcharged is to get out a voltmeter.

After fully charging the battery, the converter should drop down into a trickle charge mode (approx 13.1V for most converters), which simply maintains the battery. According to the WFCO manual, WFCO converters (common standard equipment in RVs) are supposed to drop from 13.6V (normal charging) to 13.1V after 44 hours of near constant current.

The WFCO in my A-frame will not go into trickle mode after several weeks, and with only the propane/CO detector and the stereo on. It remains at 13.7 volts, which is too high for long term storage. So I will be installing a new converter. In the meantime, I disconnect the battery after fully charging for several days after a trip.

I'm disappointed because 1) I finally figured this out 2 months after the 2nd year of warranty expired, 2) it may have caused the failure of my initial set of 12V batteries (I had 2 Size 24, one went bad and took the other one with it after bad decisions on my part), 3) the A-Frame has a combination converter/electrical panel which means more rewiring than just replacing a converter. On the bright side, I will get a better converter that will charge my batteries faster, and I can clean up the wiring rat's nest (and lack of proper color codes) that came standard behind the converter.

just my experiences, yours may differ
Fred W
2014 Rockwood A122 A-frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

p, I am not an expert, but rely on the battery manufacturers data when I make states like I do. If they are wrong, we certainly will not know better than they. 13.7v is too low for absorb and too high for float. So, this charger is junk.

And, is probably the reason your batteries aren't lasting like they should.

Absorb should be somewhere near 14.7v and depending on temperature; and as high as 15.1v it it is very cold outside, with temperature compensation in place.

I respectfully disagree with your statement that the best way to determine full is with a volt meter. Hydrometer is number one, because it isn't affected by the battery's temperature. If the battery under test was just under load or just being charged the battery is warm and needs to return to room temperature before being read. The difference in true voltage and the higher voltage is significant. Now, if the battery is sealed, a volt meter is the only way, but again the temperature needs to stabilize.
WW

[WolfWhistle]

Originally Posted by boondocking

No need to exercise the batteries, actually they will last longer the less times they are discharged.

Do you ever give them an equalize charge?
WW

[rblack22]

I leave my TH plugged in to shore power 24/7 when I'm home. Batteries are at least 3 years old and no problems.

[northstar1960]

Originally Posted by boondocking

No need to exercise the batteries, actually they will last longer the less times they are discharged.

yes batteries have a cycle life . to let them sit un used will cause them to drain over time and lose charge and shorten life . to keep them on a maintainer can and does cause them to 1. boil out 2. sulfate . both ruin batteries . some smart maintainers that will stop charging and actually put a drain on the battery then into charge mode is ok , but imo just ok .
what i do is no different then a smart maintainer other then i choose when the battery is charged and when it is used . buy doing this i have batteries that last avg 7yrs
So to use a battery and run the charge level to around 65/70% and then recharge is better then a full time maintainer . i do this on avg once a month . the batteries sit get used a few days and then fully charged . doing this once a month is a good avg and does not shorten the life of a battery.

[pgandw]

Originally Posted by WolfWhistle

p, I am not an expert, but rely on the battery manufacturers data when I make states like I do. If they are wrong, we certainly will not know better than they. 13.7v is too low for absorb and too high for float. So, this charger is junk.

And, is probably the reason your batteries aren't lasting like they should.

Absorb should be somewhere near 14.7v and depending on temperature; and as high as 15.1v it it is very cold outside, with temperature compensation in place.

I respectfully disagree with your statement that the best way to determine full is with a volt meter. Hydrometer is number one, because it isn't affected by the battery's temperature. If the battery under test was just under load or just being charged the battery is warm and needs to return to room temperature before being read. The difference in true voltage and the higher voltage is significant. Now, if the battery is sealed, a volt meter is the only way, but again the temperature needs to stabilize.

A hydrometer is a more accurate read than a voltmeter - but it's reading the battery, not the converter. The OP was asking if his battery was being overcharged by his converter. The voltmeter tells me what my converter is doing when it is on - a hydrometer does not.

As far as charge voltages, what the battery manufacturers say only matters to the designers of converters. RV converters have preset, non-adjustable voltage points - at least models that will fit in a 12ft box A-frame. Temperature compensation is a joke when my batteries are out on the tongue, and the converter is inside under the dinette, next to the water heater.

The "normal mode" for both Progressive and WFCO converters is preset at 13.6 volts (my voltmeter measured 13.7 on my WFCO - either meter or converter calibration could be off by 0.1 volts).

Storage (trickle) mode on WFCO is 13.1V; PD says 13.2V. The WFCO cutover from normal is 44 hours, PD uses 30 hours. My problem is that my WFCO would never drop from normal mode into storage mode. That's why I'm replacing my WFCO, and not because of 13.7V normal mode output.

Absorb ("boost") mode is advertised by both WFCO and PD as 14.4 volts. Can most batteries handle a higher absorb voltage at normal temps, and thereby charge a little faster? Yes, but the higher the voltage, the more monitoring that should be in place to prevent boiling.

Bottom line is that no readily available converters for small RVs come close to meeting your proposed specs. I trust converter manufacturers like PD to put out a good automatic product that does not inadvertently destroy batteries.

My battery bank is two 232AH 6V Interstate golf cart batteries because they will carry me for 4 nights (high 20s or warmer) in Colorado without recharging. That's as long as we will stay in any one place with our A-frame. We wanted to keep things simple for weekend camping, which is why we chose an A-frame in the 1st place. No generator and fuel to lug, no solar panels to position.

And if my batteries only last 5 years instead of 7, I'm OK with that. I didn't waste camping time checking them with a hydrometer, and I only paid $150 for the pair, including tax. I just want the converter to recharge them fully when I'm at home so they are ready to go for the next trip.

Fred W
2014 Rockwood A122 A-Frame
2008 Hyundai Entourage minivan
camping Colorado and adjacent states one weekend at a time

[boondocking]

Originally Posted by WolfWhistle

Do you ever give them an equalize charge?
WW

When they are being used in the summer I will do an equalization once a month. They are kept charged via solar.
If they are in storage for the winter a good maintainer is used. They will not sulfate or boil off if using a good maintainer.