'Nuther battery thread

[boowho]

Today I was talking with a solar dealer and happened to mention that my 4 Trojan house batts (that I installed new last January) have NEVER needed to have water added to them.

He said that this is not good, since it indicates they are being charged at to low of a voltage.

I haven't been able to see an option on the Magnum control panel to adjust this.

SO...... Need I worry about this??

Boowho??

[Flybob]

Statement from Trojan site on Battery Maint.

Deep-cycle flooded/wet batteries need to be watered periodically. The frequency depends upon battery usage and operating temperatures. Check new batteries every few weeks to determine the watering frequency for your application. It is normal for batteries to need more watering as they age.

[jcowles3]

I think our inverter panel has an option of what type of battery you have and it charges them differently. I think I read here that if you set it wrong you fry the batteries. Be careful...


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[dan-nickie]

Well, I thought the Magnum Energy Center allowed all the parameters to be programmed as you wish. Have you checked the manual?

[Still Kickin]

Two group 27's going on two+ years usage. Have taken them down to around 50% many times boondocking, and only had to water them once. Hydrometer test says they are still in the good range. Many times the recharging happens during flight to the next destination, which can be a few hours or more. This is a class C equipped with a 14v 220 amp alternator.

The onboard three stage converter takes over when plugged into shore power. So, that statement in boohoos post by the battery guy, may not be completely accurate regarding slow charging. Just sayin'

[garbonz]

if it ain't broke don't fix it.


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[camaraderie]

Boowho...I tend to agree with the guy in the shop...to a certain extent. Modern 3 stage chargers cause much less boil off than the old ones did... and if you never let your batteries get too low (i/e/ not much boondocking) ...the most they are gonna see is in the mid 13Vrange since bulk charging will not be needed. This will lead to sulfation over the longer term ESPECIALLY if you don't have a built in or manual EQUALIZATION process as part of your charger functions...since the solution will stratify and not get hit during charging with enough voltage to stir things up to keep the H2SO4 well mixed.
Suggest 2 things:
1. Check to see if you CAN equalize with your setup. If NOT...then...
2. Run down your batts to 12.2V while unplugged. Then plug in and charge. Wait about 5 minutes and measure voltage at the battery terminals...You should see something in the 14.2-14.6 range typically. If you are not seeing this then something IS wrong with your charging setup. If you do see 14+ Volts...then all is well and you should just do a similar discharge/charge every couple of weeks or at least once a month.

The other thing I might question is the size of your charger in amps. You have around a 425 amp hour bank. ... this means you should have a charger that is at LEAST 40 amps and preferably in the 80 amp range.
If you need to replace your charger for any of the above issues...suggest you get one with an EQ cycle...both Progressive and Iota make good ones with their Genius and Smart module models.
Good luck!

[garbonz]

Originally Posted by camaraderie

Boowho...I tend to agree with the guy in the shop...to a certain extent. Modern 3 stage chargers cause much less boil off than the old ones did... and if you never let your batteries get too low (i/e/ not much boondocking) ...the most they are gonna see is in the mid 13Vrange since bulk charging will not be needed. This will lead to sulfation over the longer term ESPECIALLY if you don't have a built in or manual EQUALIZATION process as part of your charger functions...since the solution will stratify and not get hit during charging with enough voltage to stir things up to keep the H2SO4 well mixed.
Suggest 2 things:
1. Check to see if you CAN equalize with your setup. If NOT...then...
2. Run down your batts to 12.2V while unplugged. Then plug in and charge. Wait about 5 minutes and measure voltage at the battery terminals...You should see something in the 14.2-14.6 range typically. If you are not seeing this then something IS wrong with your charging setup. If you do see 14+ Volts...then all is well and you should just do a similar discharge/charge every couple of weeks or at least once a month.

The other thing I might question is the size of your charger in amps. You have around a 425 amp hour bank. ... this means you should have a charger that is at LEAST 40 amps and preferably in the 80 amp range.
If you need to replace your charger for any of the above issues...suggest you get one with an EQ cycle...both Progressive and Iota make good ones with their Genius and Smart module models.
Good luck!

If you run the batts down to 12.2 you WILL NOT see 14.2 for quite awhile, as you will be running on the bulk charge cycle until the batts get close to 80% or so. with that large a battery bank and a small charger, that would be several to 10's of hours.

Does the OP leave the rig plugged in? If not then there is no reason they would lose much water. Plugged in all the time, then yes they should lose at least some water over time at the resting voltage of 13.2 or so.


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[boowho]

Hey, thanks all....stratification was mentioned by the solar guy as what would be happening if no water being lost.

MY Magnum IS set for flooded type batts, but i don't know if it has equalization capability built in or not.

One other thought.... the Magnum keeps track of lots of data. It shows my highest voltage since the new batts installed as 14 point something. Shows lowest down in the 11 point something range. 11 sounds like a super dead battery to me, but my BM has been showing 100% SOC almost (if not ) ALL the time since I installed them.

Magnum max charge rate is around 70 AMPS if I remember correctly.

Anyhow, thanks for all the ideas/suggestions.

Boowho??

[camaraderie]

Garbonz...it actually depends on the individual charging parameter program from each mfr ... most will rise fairly rapidly to ...14.2 to 14.6 which is the nominal bulk charging voltage of most 3 or 4 stage chargers and the current will ramp up as well to full rating of the charger. This will last until absorbtion phase when the current will DROP gradually and voltage will hold till it begins to drop to the mid 13V range and then finally it will finish at float stage.

YOU and I can both be right on this one since individual mfrs. will choose their own approaches. My Xantrex (boat system) used to get to 14.6 in a few minutes and I ALWAYS ran my batteries down to 12.2 or 50% capacity based on my Victron. I checked last week minutes after plugging in to the wall with a battery at 12.35 and was at 14.2 at the battery terminals on my 2015 Georgetown.

The thing we DO agree on in any case is that resting state voltage is the same as float and is characterized by a LOW amperage in the range of 1-2% of total battery capacity..i.e. 13.2 Volts at 1-2 amps for a typical group 27 or 31. This will take a long time to boil off anything which is why the little maintenance chargers like Battery Tender operate in this range safely all winter for folks....and why leaving a coach plugged in full time stirs up very little unless it has a built in EQ cycle.

For BooHoos purposes... the important thing is that he does drop to 50% charged so that he gets a good long run (in bulk and aborption) over 14.2 volts which IS the point at which wet cells gas. Unless you get to this point or greater...you are leaving sulfate on the plates...and a well discharged battery will hold this level longer than say a 25% discharged battery.
Maybe Boohoo can tell us how long it takes his system to ramp to that voltage from startup once he has a go at it.

[Campin Cajun]

I hate batteries. Just saying......

[garbonz]

I'm just saying that 4 trojan house batteries with upwards of 300-400 AH of capacity will take awhile on bulk charge which, by definition, will stop when the batts are at 14.4 or so volts and shift to the absorption cycle at that point. The OP has a 70 amp charger (which would probably not actually keep the 70 rate vary long as it heats up). Most chargers DO NOT deliver their rated power very long, and drop off to less than that. I too have used a Victron and other real time monitors and bulk charge should ALWAYS take several hour from 50% discharge. Wet cell batts should never be charged at more than 25% of their capacity, they can't take more amps than that without damage. A 70 amp charger sounds about right for that battery bank and should take several hours to reach the 14.4 point,

My only concern is if the OP is expecting to see 14.4 volts right away when charging, they arn't gonna see that for several hours and that indeed is normal.

Sulfation is also not as big a problem as most people think, unless you keep you batteries plugged in all the time. MFG's of these "sulfation" chargers have a vested interest in making this issue bigger than it is.

Best thing to do is to disconnect your batteries whenever possible, charge them occasionally when they drop 10% or so to keep them up, AND cycle them down to 50% or less and back up, a couple times a year to exercise the plates and electrolyte. Battery tenders are not necessary, but man do the MFG love to sell them to you.

Just my Opinion, after more than 40 years with Boats and RV's and lots and lots of batteries.

Thanks for all the great discussions.


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[camaraderie]

We're in about total agreement! I'd add pulse chargers to the list of gimmicks too.
Have a great Christmas.

[SKnight]

The solar guy is completely correct.........10 years ago.

Back in the day, a charger put XX power to the battery, even the automatic ones put XX amp rate until the battery quit absorbing power, the voltage would go up, the charger would quit.

Now, most any charger/converter is a smart or multi stage through the advent of processor technology. A 70 amp rate might start out at 70 amps, but progresses through 40, then 20, then 10, then float which is a very slow rate. The numbers are arbitrary, but show the example.

That means that the batteries don't endure as much as they charge, they don't get as hot, meaning they don't boil off water like they used to.

So, we lose very little water. I've had four 6V batteries in mine for four months now, cycled them from 12.3V to fully charged for over two weeks straight during that time, they're still full.

If you're charging rate meets your needs, then don't worry about it. If you're losing very little water I'd consider that a good thing, means you're not working them too hard.

[boowho]

Originally Posted by SKnight

The solar guy is completely correct.........10 years ago.

Now that's another point, and a good one.

For further info from the OP (me), I'm plugged into shore power about 99% of the time (being a full-timer) and rely on my Magnum interter/charger to manage the charging chore for me.

I've looked at configs I can change and one of them is Absorb Done Time which is currently set at two hours.

Other items are

VAC dropout = 80
Max Charge Rate = 100%
Battery Type = flooded
AC Input Amps = 10

Boowho??