Using RV while doing Equal. charge

[Ray,IN]

Originally Posted by twinboat

Ray,IN,

He was talking about the output voltage of the charger, it has to be higher then the batt. volts.

Any old cheap 12V battery charger has an output voltage of ~13.5VDC if it isn't broken. The amperage output is what's important to revive a totally dead battery. I've revived many with my 200A charger, after 10 minutes I reduce it to 40A, after 20 I reduce it to 10A. Downside, my batteries only last about 5-7 years.
I discovered the hard way, if the cables get clamped on backwards you can actually reverse the pos/neg field of a totally dead battery.

[TeJay]

Thanks twinboat, I thought that's what I was trying to point out. To state it in simple terms, electrons won't flow into the cells of a battery unless the charging voltage is above the voltage of the battery being charged. Yes most any charger, even cheap ones will have a charging voltage around 13.6 volts. Sometimes, depending on the resistance of the cells to accept a charge, that charging voltage will exceed 13.6-V and may go as high as 14.5 or more. However depending on the quality of the charger usually when you see a charging voltage much higher than 15.5 -V's you have a battery that may be sulfated to the point that it won't accept a charge.
That's where slow charging at 1-2 amps over 24-48 hours may revive a sulfated battery.

The only time I ever saw a battery boil and spew acid from the vents was when I tried to charge a dead battery at a high amperage. Perhaps if you start high and lower it before the battery gets to hot that will work. To avoid possible acid issues I adopted the slow charge idea. I also realize that the re-charging process takes place at the molecular level so I wanted to give it time to work. So based on what I understood about batteries we always charged at as slow (amperage) a rate as possible.

TeJay

[flaggship1]

Some good general reading on batteries here and on solar as well.

http://www.amsolar.com/home/amr/page_21

I still don't know that equalization is something that must or should be done on a routine / annual or other basis. I guess it depends on how your batteries are maintained and whether or not your charging system has a built in equalization process. A good friend told me yesterday that his system has a "Conditioning" cycle that will equalize as needed. I was surprised by that as I thought we had the same staging and it is not on mine.

From the link above re: Equalization.

What is an "Equalization" Charge? An equalization charge is a planned overcharge. As discussed above, overcharging (equalizing) a battery is not good but then neither is allowing sulphate crystals to grow. Equalization, however, is a lessor evil than sulfation. Pushing the batteries up to 14.8 to 15.5 volts for 3 to 6 hours occasionally will help knock loose hard rock sulfation and allow weaker cells to come up to a full charge. If you recognize that you will have to replace the water that 'boiled' off during this planned overcharge, you can extend the life of previously sulfated batteries.

So it appears that if your charging cycles or use are such that crystals grow, then equalizing will help keep them alive.

[AFChap]

Originally Posted by Ray,IN

I can't equalize mine though, the manual also says not to equalize sealed lead-acid batteries, and my starting batteries are sealed Interstates.

Our systems are identical, Ray. I have equalized about once a year since the coach was new, and normally seen a significant improvement in how long the house batteries last in boondocking. I "disconnect" the house batteries by tripping the disconnect switch. My understanding is that only the house batteries are equalized when the cycle is initiated ...I could be wrong, but my coach has sealed chassis batteries like yours does, and it has worked for me. My rig has a May 2002 mfg date. I replaced house batteries in mid 2007 and late 2011. I replaced chassis batteries in mid 2005 and mid 2011.

[TeJay]

When I first started reading this thread I was not exactly sure what, "Equalization" charging was all about. I suspected what it was and was assured when, "flagship1" gave his good explanation.

I don't believe all or maybe not even most coach chargers have this feature. This leads me to believe that it is just another bell/whistle to entice some to make a decision on a coach that has this feature. Believing that it will assure a longer battery life. Will it??? I'm not convinced it does.

Anytime batteries are connected there is always a chance that they will charge and discharge unequally. That's just the nature of a battery. We would/could hope that the manufacturers of batteries would strive for consistency in the build so the differences in the recharging would be minimal. The vast majority of batteries are probably used singly instead of ganged together. Golf cart batteries (6-volt) are always ganged together and I'm sure are made with this in mind and that's probably why they do so well in a MH.

My educated guess is yes equalization might/would benefit batteries. However I also believe that the difference in the life of coach batteries may or may not be extended if equalization were done regularly.

Many coach owners have never equalized batteries and probably don't even know what that is. Others may know and swear by it. Even if we don't know what that process is most of us know that it is best to always replace all batteries at the same time and always with a matched (dated) set. This avoids beginning with a mismatched set which help to prevent charging one battery more than another.

TeJAy

[Ray,IN]

Equalization is not something involving the coach. It is a specific design feature of the inverter/charger. No-one can tell when this procedure must be done without measuring specific gravity of every cell. It requires taking individual cell specific-gravity readings with a temperature-compensating hydrometer. This is explained by the University of Illinois: http://energy.ece.illinois.edu/Balog.../intelec02.pdf
for series-connected batteries.

[Ray,IN]

Originally Posted by AFChap

Our systems are identical, Ray. I have equalized about once a year since the coach was new, and normally seen a significant improvement in how long the house batteries last in boondocking. I "disconnect" the house batteries by tripping the disconnect switch. My understanding is that only the house batteries are equalized when the cycle is initiated ...I could be wrong, but my coach has sealed chassis batteries like yours does, and it has worked for me. My rig has a May 2002 mfg date. I replaced house batteries in mid 2007 and late 2011. I replaced chassis batteries in mid 2005 and mid 2011.

I don't understand how that would work. Wouldn't the BIRD relay allow the equalizing charge into the starting batteries too? I once thought about running an equalization, but this prevented me from taking action. I might have a different inverter/charger, mine is a Xantrex RS2000. Apparently the previous owner replaced the OEM.

[TeJay]

The batteries are in the coach, and the inverter/charger is also in the coach so I do believe equalization, (if your inverter/charger has that feature) does involve the coach, and its associated devices installed by the coach manufacturer.

I am familiar with temperature compensated specific gravity readings but it's been many years sine I did it. Batteries and charging systems have evolved over the years and many tests that were routinely done years ago are often not generally done today unless it is by a trained technician who can interpret those types of results. That may be why today some inverter/chargers use equalization as a routine procedure to avoid using a hydrometer to determine if it needs to be done. And I don't really believe most owners would do it if they had to. That's why I deduced that perhaps, except in some instances, that it was not really a necessary process to do unless one wanted toTRY to increase the life of some coach batteries.

AFChap stated that they did a lot of boon docking. Maybe in situations like that where the batteries are taken down considerably lower they might benefit from the equalization process. Most (don't know the percentages) coaches probably don't run their batteries down like that.

TeJay

[Ray,IN]

TeJay, a BIRD relay is not part of the inverter/charger it is a separate piece of electrical equipment. Virtually all Winnebago diesel-pushers have had one since 2000.

It's function is to allow both coach and chassis batteries to be charged at the same time, regardless of power source. Yet it will not allow one battery bank to draw from the other.

[smiller]

Originally Posted by mel s

okcnewbie
I have had 2 sets of 12V "deep cycle marine" house batteries last 9 years in my coach without ever being "equalized".
However, if I ever did equalize my batteries I would make sure that nothing using battery voltage saw the equalization voltage.

But it's your RV do what you think is best.

I agree. Most 12-volt devices will probably survive 15 volts but given that equalization needs to be done rarely if ever I see no need to subject DC appliances to the high voltage. I would certainly isolate the batteries.

[okcnewbie]

Thanks for the great discussion on batteries/charging and using our RV's.

One of the things I was trying to point out is, " Our DC devices are already getting 15 plus volts in cold weather. "

It's not likely that any of the DC devices would be harmed by high battery voltage. If anyone has a specific piece of equipment that has been harmed by 15.5 VDC than I would be interested in knowing about that.

Thanks again.

[wa8yxm]

Ok this is fact, antecedental fact but fact non the less.

I have two converters in this house on wheels,
The OEM is a Progressive Dynamics Intella-Power 9180 with charge wizard.

This is from the owner's manual: Every 21 hours when the system is operating in the Storage Mode, the Charge Wizard will automatically switch to the Equalizing Mode of operation. The Equalizing Mode increases the charging voltage up to 14.4 volts for 15 minutes

The other one is a Xantrex Prosine 2.0,, Not sure what the current equaliztion voltage setting is but it flashes warnings.

I The rig is 9 years old, I have used the equlazation mode on the Prosine a few times (perhaps 5) but normally just let the 9180 do the job.

Only electronics failurs have been the gas side of the water heater and the furnace. Both of these failures, I believe, were NOT caused by 12 volt issues, but by thousand volt issues (The ignition system on the DSI boards).

[smiller]

Originally Posted by wa8yxm

The Equalizing Mode increases the charging voltage up to 14.4 volts for 15 minutes

It should be noted that many chargers advertise an 'equalizing' mode but it often is actually just an occasional bump up to absorption voltage and not a true equalization. Both Progressive Dynamics and Iota and many Xantrex models all do this (raise voltage to only around 14.4 volts and call it 'equalization') when it really is not. Better than nothing probably but not a proper equalization.

The point is if you have one of these popular chargers and think 'my electronics survive equalization all the time' they are really receiving no more than standard absorption voltage. Exposure to 15.2 - 15.5 volts (as a true equalization would entail) is something different.

[Ray,IN]

Originally Posted by okcnewbie

Thanks for the great discussion on batteries/charging and using our RV's.

One of the things I was trying to point out is, " Our DC devices are already getting 15 plus volts in cold weather. "

It's not likely that any of the DC devices would be harmed by high battery voltage. If anyone has a specific piece of equipment that has been harmed by 15.5 VDC than I would be interested in knowing about that.

Thanks again.

If your battery charger is putting 15 VDC into your batteries during storage, it's boiling water away. Mine were receiving 14.4VDC in storage. I asked on escapees.com about that high float voltage, and was advised to unplug my battery temperature sensor in cold weather storage. I did, and voltage quickly dropped to 13.3, which is .2V higher than a "normal" float charge of 13.1V.