Why isn’t my battery charging?

[Ingmire]

Hi guys this is a new setup for me. Day two on my first road trip with the system.

200w solar, renogy dctodc mppt 30amp, aili shunt and ampertime 50ah battery.

So far the aili shunt tells me each day I’m only losing power to my battery. The number hasn’t gone up at all.

But during the day as I’m driving or parked the lights illuminated on the renogy dctodc mppt say that the battery is being charged.

Tonight after an 8 hour drive the battery light on the renogy is yellow. And I’m getting a reading of %70 from the shunt. Shouldn’t the battery be fully charged after an 8 hour drive? The shunt reading was %80 this morning and %90 the day before.

So it seems my battery isn’t being charged at all. Possibly.

My draw on the battery is quite small as I’m monitoring outgrowing draw with the shunt. 3.5ah at most but not very often. Mostly just pulling 1ah. Over the past two days.

I apologize for the crudeness of the setup and untidiness, I was rushed.

I’ve looked over diagrams for this mppt / dctodc and I believe I’ve got everything right.

Can anyone advise me???

 

[Bud Martin]

You say the shunt shows you 3.5Ah of current draw, so how much charging current does it show during charging?

 

[JWLV]

You said you have 200w solar. Is that 1 or 2 panels? Is it 12 volt or 24 volt? Are they in series or parallel?
According to Renogy, the max solar input is 25 volts. If total VoC of your panels is greater than 25 volts, I would assume that the Renogy would just shut down. A typical 24 volt panel usually has a VoC of 30 to 34 volts, which would exceed what the Renogy dc to dc charger can handle.

This is the first I've seen the Renogy dc to dc charger. Based on their sales literature, it appears to be designed for a 12 volt system that accepts "around" 12 volt inputs, such as from an alternator (about 14 volts) or 12 volt solar panels (about 16 volts).

 

[Zwy]

Hi guys this is a new setup for me. Day two on my first road trip with the system.

200w solar, renogy dctodc mppt 30amp, aili shunt and ampertime 50ah battery.

Panels hooked in parallel or series? Do you have the MPPT wired to vehicle alternator?

So far the aili shunt tells me each day I’m only losing power to my battery. The number hasn’t gone up at all.

If any charging occurs, you will see an up arrow during charging.

But during the day as I’m driving or parked the lights illuminated on the renogy dctodc mppt say that the battery is being charged.

Forget the lights, you have the Ali.

Tonight after an 8 hour drive the battery light on the renogy is yellow. And I’m getting a reading of %70 from the shunt. Shouldn’t the battery be fully charged after an 8 hour drive? The shunt reading was %80 this morning and %90 the day before.

So it seems my battery isn’t being charged at all. Possibly.

Doesn't appear to be charging.

My draw on the battery is quite small as I’m monitoring outgrowing draw with the shunt. 3.5ah at most but not very often. Mostly just pulling 1ah. Over the past two days.

I apologize for the crudeness of the setup and untidiness, I was rushed.

I’ve looked over diagrams for this mppt / dctodc and I believe I’ve got everything right.

Either install error or the MPPT isn't working. You need to double check everything. Do you have a multi meter to check panel polarity and voltage? And check the DC to DC cables?

Can anyone advise me???

 

[Diysolar123]

looking at your setup pictures, do you have a negative battery connection that is going "around" your shunt? hard to tell but it looks like two wires are there.

Nothing should be connected to the negative terminal of the battery but the shunt, this makes the shunt measurements the golden standard in what is going in or out of the battery.
If your shunt is working it does give you the real answer on what is going in or out of your battery. You should be able to monitor and log that data for your answer...

 

[Ingmire]

looking at your setup pictures, do you have a negative battery connection that is going "around" your shunt? hard to tell but it looks like two wires are there.

Nothing should be connected to the negative terminal of the battery but the shunt, this makes the shunt measurements the golden standard in what is going in or out of the battery.
If your shunt is working it does give you the real answer on what is going in or out of your battery. You should be able to monitor and log that data for your answer...

thank you fir the reply!!

You are correct there! I do have 3 wires coming off negative terminal of the shunt.

#1 going in to shunt out to 12v fuse block

#2 going to mppt

#3 to ground chassis

I wasn’t sure how to have wires 2 and 3 in the system without hooking them to the negative battery terminal?

 

[Ingmire]

Panels hooked in parallel or series? Do you have the MPPT wired to vehicle alternator?


If any charging occurs, you will see an up arrow during charging.



Forget the lights, you have the Ali.


Doesn't appear to be charging.



Either install error or the MPPT isn't working. You need to double check everything. Do you have a multi meter to check panel polarity and voltage? And check the DC to DC cables?

Panels in parallel. 2x 100w panels.

Mppt is wired to vehicle battery.

Thanks for the advice!

 

[Q-Dog]

If you want to measure charge current going into the battery, it needs to go through the shunt. The shunt can't measure what it can't see.

 

[Ingmire]

You say the shunt shows you 3.5Ah of current draw, so how much charging current does it show during charging?

I haven’t seen it show any charging.

 

[Ingmire]

You said you have 200w solar. Is that 1 or 2 panels? Is it 12 volt or 24 volt? Are they in series or parallel?
According to Renogy, the max solar input is 25 volts. If total VoC of your panels is greater than 25 volts, I would assume that the Renogy would just shut down. A typical 24 volt panel usually has a VoC of 30 to 34 volts, which would exceed what the Renogy dc to dc charger can handle.

This is the first I've seen the Renogy dc to dc charger. Based on their sales literature, it appears to be designed for a 12 volt system that accepts "around" 12 volt inputs, such as from an alternator (about 14 volts) or 12 volt solar panels (about 16 volts).

2 100w panels in parallel

 

[Ingmire]

Panels hooked in parallel or series? Do you have the MPPT wired to vehicle alternator?


If any charging occurs, you will see an up arrow during charging.



Forget the lights, you have the Ali.


Doesn't appear to be charging.



Either install error or the MPPT isn't working. You need to double check everything. Do you have a multi meter to check panel polarity and voltage? And check the DC to DC cables?

I will double check everything. I don’t have a multi meter but I will get one! What should I look for when buying a meter? I went to the store and there are many choices.

 

[Sirtate]

thank you fir the reply!!

You are correct there! I do have 3 wires coming off negative terminal of the shunt.

#1 going in to shunt out to 12v fuse block

#2 going to mppt

#3 to ground chassis

I wasn’t sure how to have wires 2 and 3 in the system without hooking them to the negative battery terminal?

It seems that there is a cable running from the battery negative terminal to the Renogy Box.
I am running the same AiLi shunt. It is imperative that all negative loads pass through the shunt.
As mentioned earlier, only the shunt should be connected to the battery, and the negative loads need to be connected to the 'P' side of the shunt. (which appears to be the Bus Bar)
If you have loads or the charger bypassing the shunt, the shunt can't count the electrons going 'In' and 'Out' (literally what it does, hence the name Coulombmeter) and it would be like a door man trying to maintain fire safety numbers in a theatre when people are sneaking in the side entrance.

 

[Bud Martin]

I haven’t seen it show any charging.

Can you zoom out the picture #1?
I looks (picture is cutout on the bottom) like that the Black wire from the charger goes directly to the Negative post of the battery terminal which means you will not be seeing the charging current on your Shunt monitor as mention by Sirtate.
It will help if you draw out the wiring.
BTW, that small positive red wire from the shunt to the Positive post of the battery should have small fuse for it in case you have short circuit that small wire will catch on fire.

 

[Zwy]

I will double check everything. I don’t have a multi meter but I will get one! What should I look for when buying a meter? I went to the store and there are many choices.

Just a digital one, doesn't need to be fancy as you will just be measuring voltage most of the time. But get one with nice leads or buy a quality set of leads.

As others mentioned, you need to have all current thru the shunt, no other cables running around the shunt. You could add a negative busbar and have the shunt in between the busbar and battery or you could put the cable to Renogy negative to the shunt P- side until you can source a busbar.