replaced aux battery, meter doesn't read the charge

[K1ngN0thing]

I replaced my dead flooded wet cell for a lower amp hour AGM. My panel reads "charging" even when it's not. Even after discharging to 12.4v, it hasn't changed. I can't for the life of me figure out why a simple battery replacement would cause this.

 

[LeeRevell]

Many garages and battery stores offer a free load testing for batteries.  It is possible to have gotten one or more bad batteries.

 

[B and C]

I replaced my dead flooded wet cell for a lower amp hour AGM. My panel reads "charging" even when it's not. Even after discharging to 12.4v, it hasn't changed. I can't for the life of me figure out why a simple battery replacement would cause this.

I'll take a stab since Sternwake is taking a sabbatical.

I don't know if you are charging off shore power or your new solar.  If shore power, I would check the breakers and fuses in your power center for charging voltage (higher reading) or battery voltage (lower reading) by removing a fuse and checking the now open circuit at the fuse connection (each side) to ground.  I changed the guts of my power center to a Progressive Dynamics in my Roadtrek.  It made a huge difference in my battery not getting boiled dry in a month...

Your solar charge controller is in the middle of the solar charging circuit.  If you are charging from solar, I would start disconnecting wires at the charge controller to your battery and measuring voltages from the solar and the batteries.  This is 50/50 trouble shooting.  Start in the middle and work your way toward the trouble by taking voltage measurements from both directions each time you break the circuit.  I am assuming (you know what this means :angel: ) that a connection is broken somewhere in the circuit by maybe pulling on a connection too hard that caused it to go open or shorted a hot wire while changing the battery and blew a fuse.

I don't have solar yet, so am unsure of how to properly trouble shoot this.  The 50/50 principal still applies though.

my $0.02 worth

Brian

 

[B and C]

Forgot the first step!  Make sure no fuses are blown (boy, I blew that one).  You should have several in your battery/charging circuits.

Brian

 

[K1ngN0thing]

This battery isn't connected to solar or my charge controller; it's the one that comes with the RV. All I did was swap the old battery with a new one. It was reading the old one correctly just a day before.

 

[MikeRuth]

I'm sure you have seen the many posts here that describe how an AGM battery has different charge requirements than Flooded batteries.
AGM's tend to need a slightly higher voltage and take longer to top off.

I will tell you that putting a AGM into my Ford Van was a mistake as the charging settings were not correct for it and I have nursed it for two years now knowing the battery will never be as good as it could have been. I'll go back to flooded next time.

Now as for the meter telling you it is still charging, do you have a clamp on amp meter? If so check the charge rate, that way you can verify the panel meter.

Can you charge the AGM from a shore battery charger, ie give it a overnight charge? I'm guessing like most it was not fully charged when you received it. 

About the best I can offer with the info at hand.

Mike R

 

[akrvbob]

I can't understand your question. I'd suggest you rewrite it and give details for every part of it.

So now you have no charging sources but you have a "panel" that says it is charging. What panel and what exactly does it say?
Bob

 

[Bela's Mom]

Please don't be offended by my question.  Is your 12 volt disconnect switch in the disconnect position?  If you are plugged into shore power, your panel may show that your converter/charger is putting out voltage but it may not be getting to the battery if the disconnect switch is in the disconnect position; which it should have been when you changed the battery.

 

[highdesertranger]

yeah I am having a hard time trying to figure out exactly what's going on. let me try.
1 you replace the house battery in your RV.
2 it says it's charging but it isn't.
what says it's charging?
3 what voltage is your battery reading?
4 what is you charge source?
highdesertranger

 

[LeeRevell]

Still think the battery should be tested.  The symptoms point to it.  It's a free check.  Worth the peace of mind at the very least.  ALWAYS eliminate the simplest possibilities first, Troubleshooting 101.

 

[K1ngN0thing]

yeah I am having a hard time trying to figure out exactly what's going on. let me try.
1 you replace the house battery in your RV.
2 it says it's charging but it isn't.
what says it's charging?
3 what voltage is your battery reading?
4 what is you charge source?
highdesertranger

2. The built-in monitor panel that Roadtrek put in: http://3.bp.blogspot.com/-ILT5n0zIQIk/UiOqS32zOQI/AAAAAAAAAFg/oHACuSKMN40/s1600/IMG_0959.JPG
3. Came at 13.something and is now at 12.6 after some use.
4. Shore and alternator.

Still think the battery should be tested.  The symptoms point to it.  It's a free check.  Worth the peace of mind at the very least.  ALWAYS eliminate the simplest possibilities first, Troubleshooting 101.

The battery does charge.

 

[K1ngN0thing]

I'm sure you have seen the many posts here that describe how an AGM battery has different charge requirements than Flooded batteries.
AGM's tend to need a slightly higher voltage and take longer to top off.

I will tell you that putting a AGM into my Ford Van was a mistake as the charging settings were not correct for it and I have nursed it for two years now knowing the battery will never be as good as it could have been. I'll go back to flooded next time.

Now as for the meter telling you it is still charging, do you have a clamp on amp meter? If so check the charge rate, that way you can verify the panel meter.

Can you charge the AGM from a shore battery charger, ie give it a overnight charge? I'm guessing like most it was not fully charged when you received it. 

About the best I can offer with the info at hand.

Mike R

The meter isn't clamped on, but there are 3 wires bolted to the terminals: a + and - of your standard size for a single battery, and a thicker, insulated cable going to the pos.

I had shore plugged in for an our or two and measure an increase in voltage, showing it had been charging.

 

[highdesertranger]

so on that battery meter I assume,
L = low
F = full
C = charging
G = ? what does G stand for.
so you are saying the light on C stays lit all the time and nothing else?
have you try to reset it by disconnecting power and then reconnecting. highdesertranger

 

[LeeRevell]

The battery does charge.

Ah, good.  That was not pointed out initially.  Then suspect a bad meter unit or wire/connection for it.
See, eliminating the simple stuff first helps with troubleshooting.

 

[K1ngN0thing]

Disconnected the battery, connected a dead 11.something volt and it read correctly as depleted. Is it just that AGM have a higher max voltage, and my system is calibrated for a flooded wet cell?

 

[B and C]

OK.  I am going to try again.  The picture you posted cleared up a lot. 
The monitor panel:
[font=Verdana, Arial, sans-serif][font=Verdana, Arial, sans-serif]C = charged[/font][/font]
[font=Verdana, Arial, sans-serif][font=Verdana, Arial, sans-serif]G = good[/font][/font]
[font=Verdana, Arial, sans-serif][font=Verdana, Arial, sans-serif]F = fair[/font][/font]
[font=Verdana, Arial, sans-serif]L = low[/font]
[font=Verdana, Arial, sans-serif]These indicate approximate state of charge of the house battery.  Your picture does not show any lights and the battery switch appears to be in the "off" position.  This could be your problem.  The battery switch has to be in the "on" position to connect the battery to the charging system and to the house part of the rv.  This should be in the on position to charge from shore (or alternator).  I have a RoadTrek too.  [/font]

[font=Verdana, Arial, sans-serif]My house battery has three wires on it.  They are: one ground cable, one positive cable and another positive cable to the generator.[/font]

 

[MikeRuth]

When all is said and done your going to find it showing a charge frequently, I can almost guarantee it. It's the nature of the AGM battery.
As I said about mine, My ford 2006 E-150 was built with a FLA Battery, and then I put the AGM in, it never kept it topped off as it should due to the differences in the battery design and requirements.
Pretty sure I had also said in another thread that I will no longer use AGM in a car van or whatever that originally had a FLA or SLA starting battery as the charging circuit is not designed for AGM. Most likely your RV's house charging circuit to is not designed for it.
At this point you have the battery in, I'd just go with it and not worry to much about that indicator. When possible use a shore powered charger with AGM design to top it when you can.

Mike R

 

[B and C]

Followup to my earlier post.

When I put my 325 ah worth of AGM's in my RoadTrek, I changed the charge controller (where the fuses and circuit breakers are) from the one that came with it to a Progressive Dynamics 30 amp charger.  It was an exact replacement.  The included instructions were clear (to me at least, I am a telephone man and used to race cars).  Before I changed the charge controller, it would boil my house battery dry in short order.  I now always leave mine plugged into  shore power when available and the PD charge controller has the advantage of all the 12V circuits being filtered (no annoying whine when plugging in an audio device).  If you have not done this, I strongly recommend it as the stock charge controller will ruin an otherwise good battery (no matter if flooded or AGM).

I don't remember if you have changed it or if it was Big T.  I have read so many threads.......... :s

 

[K1ngN0thing]

@B and C that's just a photo I found online, but it's the same panel. But it looks like I was right in suspecting that it's the fact that my system isn't calibrated for AGM.

Guess I'll just burn this battery up and replace it with a flooded when it's done. Hate the idea of having to constantly maintain a battery.

 

[B and C]

That is why I got the PD charge controller.
This is the one I installed ([font=Tahoma, Geneva, sans-serif]PD4635V[/font]).  My stock one was a 30 amp Magnatek   About $180 to replace though plus the shunt (was cheap).  Not cheap and was well worth it to me for the peace of mind.  I think I spent about $200 all together.  I don't like to check batteries either and mine are a pain to get to.

Leave your shore power connected for at least 24 hours (not a couple).  You said it was charging but not getting charged.  I do not even look at that battery gauge any more.  I installed a Trimetric TM-2025 and mounted it under the existing battery gauge.  You may have to find another place for it though.   I look to the battery center (as I call it).  

From their website:

[font=Arial, Helvetica, sans-serif]Note: Requires either a 100 amp or 500 amp shunt.[/font][font=Arial, Helvetica, sans-serif] - TM-2025RV version is a little less wide than the TM-2025A, [/font][font=Arial, Helvetica, sans-serif]comes with its own cream colored enclosure designed to be surface mounted to a wall, so does not need an additional mounting enclosure.[/font][font=Arial, Helvetica, sans-serif] The TM 2025 is intended to help maintain battery systems for 12V to 48V deep cycle battery systems, such as ones found in RVs or off grid homes which are regularly charged and discharged. The amps or watts display measures the rate of energy going in or out of your batteries so you can check your charging systems, and also to see how much energy each of your appliances use to help you conserve energy. The % Full display will help you keep track of how charged or discharged your batteries are. The volts display will let you discover if your charging systems are charging to the proper voltage, which is important for maximizing your battery life. The days since charged display shows how recently the main battery (system) was fully charged, so if it hasn't been charged recently you can perform extra charging if necessary to help maintain the capacity of your batteries. The TM-2025 also can measure the voltage only of a second battery set, such as the starting battery, or solar voltage input to a charge controller. 1 year warranty[/font]

[font=Arial, Helvetica, sans-serif]Brian[/font]