AGM Batteries (weird battery drain scenario)

[bclemens]

Recently, we had an odd situation come up.

Customer complained of a massive battery drain. Not just sort of bad, but claimed he was depleting his batteries in 2 hours. He felt it was our wiring, dealer found nothing wrong. Then he claimed chassis wiring, they found nothing wrong. We asked if the batteries had been tested, he said they had. Problem persisted and seemed random. I brought it in to my tech and we couldn't find anything wrong. Batteries checked out. We checked draws, etc. We figured we would go ahead and replace the batteries to be safe and on a whim my guy checked the battery coming out. The battery had an internal short. We contacted the AGM battery guys to come out and take a look. They said what likely happened is that a normal automotive charger was hooked up to it and left. Those are not designed for AGM's and the customer likely blew a cell. That was shorting the battery and sending power through the ground. That should have been caught very early...but for some reason the issue was intermittent.

I asked for a quick PDF on batteries...something we could give to customers to warn them of using the wrong charger.

Attached is what they gave me (a little long and dry, so I will make it pretty), but some very good information if you like that sort of thing.

So anyway. PSA. If you use an external charger for any reason...make sure its the right type.

[RV Randy]

Originally Posted by bclemens

Recently, we had an odd situation come up.

Customer complained of a massive battery drain. Not just sort of bad, but claimed he was depleting his batteries in 2 hours. He felt it was our wiring, dealer found nothing wrong. Then he claimed chassis wiring, they found nothing wrong. We asked if the batteries had been tested, he said they had. Problem persisted and seemed random. I brought it in to my tech and we couldn't find anything wrong. Batteries checked out. We checked draws, etc. We figured we would go ahead and replace the batteries to be safe and on a whim my guy checked the battery coming out. The battery had an internal short. We contacted the AGM battery guys to come out and take a look. They said what likely happened is that a normal automotive charger was hooked up to it and left. Those are not designed for AGM's and the customer likely blew a cell. That was shorting the battery and sending power through the ground. That should have been caught very early...but for some reason the issue was intermittent.

I asked for a quick PDF on batteries...something we could give to customers to warn them of using the wrong charger.

Attached is what they gave me (a little long and dry, so I will make it pretty), but some very good information if you like that sort of thing.

So anyway. PSA. If you use an external charger for any reason...make sure its the right type.

Makes sense but I have to ask the question: Why would you hook up an external battery charger to batteries that have their own onboard charger? If you have AC power to run an external charger it could just be plugged into the coach to use (I assume) the correct type onboard charger?

I know we use tons of all type of batteries for emergency back up DC power systems and solar systems. It is not uncommon to get brand new cells that have internal shorts like this. It seems to be impacted to some degree by how long batteries have set in storage without being charged and what temperatures they experience while in storage.

But good info to know.

[bclemens]

"Why" is indeed the question. But I know that if someone has it at a garage, and the batteries are dead they can hook up a boost charger to get them up good and quick.

[mookieblaylock]

On the subject, I'll ask what's probably a dumb question - are the batteries in our DX3's wet cell/flooded or AGM. I was under the impression that they were flooded batteries, but the 'battery type' on the inverter control panel, and the 'battery type' on the solar control panel were set differently in our coach (inverter set to flooded, solar panel set to AGM). The setting seems to control the max voltage applied to the batteries while charging. I would assume these need to match, so I set the solar control panel to flooded.

[bclemens]

Battery, intimidator 12 volt grp 4d 198 a.h. Agm type

[RV Randy]

Originally Posted by mookieblaylock

On the subject, I'll ask what's probably a dumb question - are the batteries in our DX3's wet cell/flooded or AGM. I was under the impression that they were flooded batteries, but the 'battery type' on the inverter control panel, and the 'battery type' on the solar control panel were set differently in our coach (inverter set to flooded, solar panel set to AGM). The setting seems to control the max voltage applied to the batteries while charging. I would assume these need to match, so I set the solar control panel to flooded.

Mine came the same way but I set both to AGM.

[rskeans]

The DX3 spec sheet says AGM.

[mookieblaylock]

Sweet...glad I asked!

[Lawrosa]

Hi. What you want to know is the charging parameters of said batteries..

The 8a4d batts from deka are monoblock design.

Bulk and absorption voltages should not be more then 14.4 volts. This is what the house converters in the coaches/rv's are usually set for. ( With the charge wizard in bulk mode is 14.4 typically) Minimum bulk/absorp voltage is 14.1

Floating is a bit low though with typical on board converters. They usually float @ 13.2. Deka 8a4d's want 13.44-13.56. So a bit of a discrepancy there.

The other issue is these converters go to 13.6 v once out of bulk. They stay there some 30 hours before hitting float. It would be better if the converter never went into float for these batterys.

( But maybe they are special made converters for dynamax? IDK)

Also typical converters equalize every 21 hrs or so for 15 minutes at 14.4. Deka states an equalization so I would not worry about it. Some tout no EQ for agm.

With that said the guy who set his solar to flooded batts, that bulk/absorp voltage will most likely be too high... Flooded batts usually have a 14.8 setting for bulk...

Put the solar controller back to agm mode. And go into the settings and tweak them per deka.

14.4 bulk
14.4 absorption
13.5-13.6 float
14.4 Eq.



Read here for charge parameters

http://www.eastpennmanufacturing.com...eters-1913.pdf


Also to get the fastest charge you can hit these batterys with 30% of the c/20 rate. ( For those that boondock)

396 amps @30% = 118 amps. ( Now it will be hard to get solar to crank that in.)

And I believe dynamax gives you a 90 amp converter/charger. If its close to the batts and thick wire you may get close to that amperage.

So start that generator and make sure the converter goes into bulk mode. Its time based of 4 hours. It may only put 90 amps in for a short time. Then the amps start tapering. ( LED on charge wizard tells you what mode your in.)

So running you gen for 4 hours from 50% discharge is the best you can do to charge them while boondocking. Solar will help the cause. Solar should take over from there after the 4 hours.

But to what clemens stated, home chargers are often automated. And battery type must be inputted into the charger for proper voltages before charging.

If you use an old style dumb charger these often charge at 14.7-15.3 volts. No good for AGM's...

Just my 2 cents...

[card16]

Thanks for all of the great information from each of you.

[ablarson]

Is the onboard charger in a ForceHD suitable for AGM?

[Lawrosa]

Originally Posted by ablarson

Is the onboard charger in a ForceHD suitable for AGM?

Depends on what you have as a charger?

On the dx3's I believe they use magnum inverter chargers. These voltages can be set with the remote panel AFAIK.

Page 52 and 53 here..

http://www.magnum-dimensions.com/sit...s%29_Web_0.pdf

These voltages should be set to your battery manufacturers charging specs, For bulk ,absorption, float, equalize...

The 8a4d specs were in my previous post. If that's the batts one has in their dynamax.

http://www.eastpennmanufacturing.com...eters-1913.pdf

I believe they put in this panel from progressive dynamics that does a 50 amp 30 amp split to the inverter/charger

https://www.progressivedyn.com/rv/ac...0-amp-240-vac/

Very nice design IMO. I would assume a separate DC panel somewhere?

------------------------------------------------------------------------------

As far as the force is concerned im not sure what they are putting in.

From reading here it would seem is a 90 amp power center here.

https://www.progressivedyn.com/rv/po...r-4500-series/

That's fine but they would need to use a breaker for the inverter and have a sub panel somewhere...


And no. The voltages are not correct for the 8a4d batters with this type of converter thats non adjustable. That is if you follow the battery manufacturers suggested parameters. The float mode is the issue. 13.2 when the batts want 13.44-13.56.

With voltage loss through the wiring maybe 13.1 at the batts?

I'm just typing what would be my concerns if I owned a dynamax with regards to battery charging.

But that's where the solar comes in. It should take over after the the bulk charge is done and float at the correct voltage per your settings.

They should really give you options to add more factory panels and an mppt controller as a boondocker package.

[steverkemp]

I can see how I could use an external charger. Historically, i bring my house batteries into the garage in the winter and put them on a trickle charger. No power where the coach is parked. Sounds like I may want to rethink that approach when I get my DX3

[Lawrosa]

They do have adjustable type converters but would require manual input from the owner.

Most times set @ 13.5 volts. If you need charging while boondocking simply increase voltage to 14.4..

But you would need to have room to put this near the panel. Not sure how they are laid out in the force.

PMBC-12 Volt - Power Max Converters

Amazon seems to be out of stock.

https://www.amazon.com/Powermax-PMBC...ct_top?ie=UTF8

[bclemens]

On all of our new ones, we use a Progressive Dynamics converter with charge wizard. It would really depend on what year. They used to run a WFCO one I believe before I got here...2015-ish.

[Lawrosa]

Originally Posted by bclemens

On all of our new ones, we use a Progressive Dynamics converter with charge wizard. It would really depend on what year. They used to run a WFCO one I believe before I got here...2015-ish.

Mr Clemens, is there some type of sub panel they use for this set up with the PD panel to get the inverter to work? ( In the force units)

It would seem there would have to be as its not like the DX3's with the split panels.

Just wondering is all.

Iota just came out with battery specific modules which is very interesting. It seems iota is the only one to offer proper charging parameters for batteries manufacturers . ( Unless the owners do a adjustable as I stated above there is really not many options out there)

Such as the IQ4 which does 14.8 and 13.6 float for lead acid.

They now have an AGM module and I have a call into iota to see what specific voltages, time algorithm they actually use.

https://www.iotaengineering.com/IQ/#!/

But it is a stand alone unit. You pick what module you want apparently. I understand your take that it would not be cost effective to offer this, or what you put in the DX3's as an option in the force units.

You'll end up having a force in DX3's clothing. And you need to draw the line somewhere right? LOL.

How easy would it be to replace the force inverter with a inverter charger like you use in the DX3?

I would assume disconnect lower charging circuit in PD and just replace the inverter with the inverter charger.. And just run new battery cables from inverter to batterys.