Low Ah Reading on new battery?

[Scotsman]

This isn't specific to Forest River campers, but on my very small, simple Palomini travel trailer I have a 100W solar panel. With a new 100Ah AGM battery (not yet used - just installed on camper) the controller reads FULL (13.6V) and yet the Ah reads from 1 to 2. Can anyone explain what's going on here? I do have the correct battery type chosen. Thanks

 

[CaptainGizmo]

What are you referring to when you say “the AH reads 1 to 2”?

If you’re looking at your on board panel, that’s telling you THE CURRENT DRAW.

The rating on a battery is a capacity; the gas tank, if you will, until the battery is exhausted.

Therefore, at 1-2 AH of current draw, your 100Ah battery would last 50-100 hours. In “theory”, and this depends at what final discharge capacity that rating was given; for example 50%, which is about as far as you want to take a standard/AGM battery.

 

[Scotsman]

What are you referring to when you say “the AH reads 1 to 2”?

If you’re looking at your on board panel, that’s telling you THE CURRENT DRAW.

The rating on a battery is a capacity; the gas tank, if you will, until the battery is exhausted.

Therefore, at 1-2 AH of current draw, your 100Ah battery would last 50-100 hours. In “theory”, and this depends at what final discharge capacity that rating was given; for example 50%, which is about as far as you want to take a standard/AGM battery.

Hello Captain Gizmo from Jackson Wyoming...thank you so much for that advice. I am referring to a reading on the Renogy Solar charge controller. Your explanation makes complete sense - however: 1) I think of Ah as being a capacity rather than an actual draw measurement - which would be just 'A' for Amps. I understand that it might be showing a draw of 1 or 2 amps - but not a draw of 1 or 2 amp-hours. That doesn't make much sense to me. But the other mystery is...there's nothing drawing power in the camper - no lights, no fridge panel - nothing - so I'm puzzled as to why there's a draw reading in the first place.
I would very much appreciate your thoughts on that.
Thank you

 

[Scotsman]

Thinking on this a little more - yes, I get it now - your explanation of 1 - 2 Amp-hours does make more sense - so no need to go over that again. That's very useful information.
I also meant to add that I try not to draw batteries below 80% - which I understand is 11.8V. - Do you think I'm being over-cautious?

 

[TJ&LadyDi]

You are correct that amps are a use measurement and amp-hours is a capacity measurement. In your first post, you seem to indicate that the reading you are seeing is on the solar “controller“ rather than on a power use monitoring panel. If that’s the case, I think what you could be seeing is the battery charger input via the solar panel, not the power draw from the battery. Are you seeing the “1-2 Ah” reading at night or on a very cloudy day as well?

Just a thought.

TJ

 

[CaptainGizmo]

Ah. Well. Solar is a whole nuther bird!!!
Solar controllers will report a lot of information including recharging levels.
As for static draw, hardly a current model coach out there uses “0” unless everything is disconnected.

 

[Scotsman]

Thank you to all who answered this - but I'm still getting nowhere - even from Renogy support - who made the solar controller. Honestly, I think my very simple rig, and very simple question, is 'below' the scope of owners of large complex rigs. (my camper doesn't have a power use monitoring panel)

I have a three component solar system: 1) A 100W Solar panel on the roof of a tiny travel trailer. 2) A 100Ah brand new, fully charged Deep Cycle battery - not yet used but mounted to the camper and wired to the solar panel via 3) A Renogy Voyager 20A PWM Charge controller. (Plus of course the wiring)

My question is: - Given that the battery is fully charged (13.6V) and it's a sunny day - is it normal that I get readings of between 1-3 Ah, and about 1A on the charge controller?
I also get a reading of 0.0 KW/h. I do have one theory of my own about the A and Ah readings - and that is - if the battery is full, and the charge controller is designed to stop charging when the battery is full - does that mean there are essentially no Amps to 'read' as there's no current flowing into the battery?

What isn't explained anywhere on YouTube or in the manual or by Renogy support is whether the Amps reading is what's being delivered to the battery, or the Amp-hours that are stored in the battery?

I would appreciate any thoughts on this.

Thank you

PS - does this response go out to all in the forum, or just back to Captain Gizmo?

 

[CaptainGizmo]

@Scotsman when you Post Reply, it's viewable to everyone.

Now, to say your rig is "below" the scope of other owners isn't fair. Sadly, the 2 of us who are trying to help, ARE in fact, owners of large Class A coaches. But, doesn't matter...solar controllers and power control panels are very similar; if not identical.

So, as to your confusions, I'm surprised you haven't sought help by calling Renogy OR Forest River (or dealer). Would be odd they can't help you, unless what you've installed is different than what they install.

But, the problem is, I haven't seen your panel or even a picture. So, I can't even tell you what your STATUS ICONS are telling you. I just glanced at your manual and there are icons that will indicate what stage/status your controller is in.

I'm sorry if my answers confused you, or weren't clear. Let me rephrase my "idea" of what you're seeing:

If it says 1-2Ah on your Controller, my "educated guess" is that the controller is telling you that your solar panel is generating 1-2 amp hours of energy. Your panel should be cycling through different readings...as this clip shows in the manual. As to the 1A reading, that should be how much current is being dumped into your battery to maintain it's charge. And, don't forget, chargers have several levels of charging: Bulk, Boost, Float, and Equalization. Those levels will fluctuate as battery state of charge and loads are evaluated.

Hope this helps.

 

[CaptainGizmo]

Our resident Solar expert, @Ericrowley18 can chime in and help clarify or correct me any further.

 

[TJ&LadyDi]

Your response is posted on the Forest River Owners Club forum, so is available for all.

Thanks for the description of your system, it helps to get a handle on just what we are looking at. First, let me say that I am not an expert on solar systems. That said, I am not a stranger to RV electrical systems and electricity in general.

Is this the unit you are using?

New Edition Voyager 10A PWM Waterproof Solar Charge Controller

Renogy Voyager 10 Amp PWM Waterproof Solar Charger Controller is featuring a bright blue back-lit LCD displaying system information,engineered to be of world-class quality, equipped with advanced PWM technology suitable for 12V and 24V off-grid applications.

www.renogy.com

TJ

 

[Kevin D Pem]

While everything is new I would suggest a battery monitor. A battery monitor keeps track of what goes into the battery and what comes out. These monitors can cost from $20.00 up. Most controllers don't do this job for two reasons. one you likely have more than one way to charge the battery. two, the power out of the battery does not come through the controller. Most monitors use a shunt for power into the battery and a shunt for the lead coming out of the battery. Honestly there is no other way to maintain a log of power state of the battery. Hope this helps.

 

[CaptainGizmo]

Your response is posted on the Forest River Owners Club forum, so is available for all.

Thanks for the description of your system, it helps to get a handle on just what we are looking at. First, let me say that I am not an expert on solar systems. That said, I am not a stranger to RV electrical systems and electricity in general.

Is this the unit you are using?

New Edition Voyager 10A PWM Waterproof Solar Charge Controller

Renogy Voyager 10 Amp PWM Waterproof Solar Charger Controller is featuring a bright blue back-lit LCD displaying system information,engineered to be of world-class quality, equipped with advanced PWM technology suitable for 12V and 24V off-grid applications.

www.renogy.com

TJ

TJ,
He indicated he has the 20A PWM.

 

[TJ&LadyDi]

TJ,
He indicated he has the 20A PWM.

I missed that; thanks Steve. Just wanted to get a look at the manual and specs on the unit to see it anything else jumped out at me. I think you have it correct that what he’s seeing is input from the solar panel. While this charge controller is a very useful device, I can’t see how it could calculate and display the aH available in the battery. As I see it, it simply manages the charging circuit by passing available power from the solar panel to the battery.

TJ

 

[Kevin D Pem]

Note: The Ah display is accumulated power from the panel. Over time this number will grow but only tells you how much power the controller supplied over an unlimited time.

The A display is telling amps at system voltage being provided by the solar panel.

If you have a W display it will be the wattage the panel is supplying and used by the controller. This is displayed in conjunction with panel voltage.

 

[Scotsman]

@Scotsman when you Post Reply, it's viewable to everyone.

Now, to say your rig is "below" the scope of other owners isn't fair. Sadly, the 2 of us who are trying to help, ARE in fact, owners of large Class A coaches. But, doesn't matter...solar controllers and power control panels are very similar; if not identical.

So, as to your confusions, I'm surprised you haven't sought help by calling Renogy OR Forest River (or dealer). Would be odd they can't help you, unless what you've installed is different than what they install.

But, the problem is, I haven't seen your panel or even a picture. So, I can't even tell you what your STATUS ICONS are telling you. I just glanced at your manual and there are icons that will indicate what stage/status your controller is in.

I'm sorry if my answers confused you, or weren't clear. Let me rephrase my "idea" of what you're seeing:

If it says 1-2Ah on your Controller, my "educated guess" is that the controller is telling you that your solar panel is generating 1-2 amp hours of energy. Your panel should be cycling through different readings...as this clip shows in the manual. As to the 1A reading, that should be how much current is being dumped into your battery to maintain it's charge. And, don't forget, chargers have several levels of charging: Bulk, Boost, Float, and Equalization. Those levels will fluctuate as battery state of charge and loads are evaluated.

Hope this helps.

View attachment 8430

Thanks Captain Gizmo - and I didn't mean that in the wrong way. I do understand the manual and the various stages of state of battery - but as this is new equipment for me I was puzzled as to why a full new 100Ah battery should show only 1Ah. However, this has been answered adequately, that it has top do with the accumulated amps delivered to the battery over time by the panel. As it is new - there have been no amps delivered. I also see an excellent answer that the controller reads only current going into the battery - not coming out of it - or in it, and a battery monitor will do that for me. Thank you again for your contribution.

 

[Scotsman]

TJ,
He indicated he has the 20A PWM.

Thank you - I've had my questions answered adequately by others - safe travels

 

[Scotsman]

While everything is new I would suggest a battery monitor. A battery monitor keeps track of what goes into the battery and what comes out. These monitors can cost from $20.00 up. Most controllers don't do this job for two reasons. one you likely have more than one way to charge the battery. two, the power out of the battery does not come through the controller. Most monitors use a shunt for power into the battery and a shunt for the lead coming out of the battery. Honestly there is no other way to maintain a log of power state of the battery. Hope this helps.

Thanks so much Kevin,

This really answers my questions and helps a great deal - as do hyour other helpful answers. I'll get that monitor before I ruin my system...

 

[Scotsman]

I missed that; thanks Steve. Just wanted to get a look at the manual and specs on the unit to see it anything else jumped out at me. I think you have it correct that what he’s seeing is input from the solar panel. While this charge controller is a very useful device, I can’t see how it could calculate and display the aH available in the battery. As I see it, it simply manages the charging circuit by passing available power from the solar panel to the battery.

TJ

Thanks TJ - I think I have it all figured out now. I wish the manual would explain this to newbies like me - what the readings actually tell you. The answers I got from Renogy were cut-and-paste auto responses that told me to check my wiring etc...

 

[Kevin D Pem]

Thanks so much Kevin,

This really answers my questions and helps a great deal - as do hyour other helpful answers. I'll get that monitor before I ruin my system...

To be honest I don't have a battery monitor. I believe large enough system does not require monitoring. If you only use an inverter or use the load connectors on the solar controller to limit the draw down of the battery you can't hurt the battery because it will not discharge below 50%. Note that the load terminals only supply 10A so a relay would need to be controlled by those terminals. I can help with a diagram to accomplish that if you need.

 

[Scotsman]

To be honest I don't have a battery monitor. I believe large enough system does not require monitoring. If you only use an inverter or use the load connectors on the solar controller to limit the draw down of the battery you can't hurt the battery because it will not discharge below 50%. Note that the load terminals only supply 10A so a relay would need to be controlled by those terminals. I can help with a diagram to accomplish that if you need.

Just when I thought I was getting everything understood...what a revelation that the battery (I presume) load terminals deliver only 10A - never has that come up before and it confuses me as to why a battery charger, for example, can deliver more than 10A if the terminals won't accept it? My system doesn't have an inverter - it has a converter only - for charging the battery when plugged into shore power (I presume) and for powering the AC outlets in the camper (Of which there are a staggering 7 duplexes in a sleeping space of 13'!) when hooked-up. This is 12V camping otherwise - which is fine because we never use hook-up camping but sometimes charge the battery from shore power at home. I don't understand what a relay is - were we talking about this? Is the monitor we're discussing also a 'relay'?