Alternator charging light staying on. Renogy DCC50S

SeanF1

SeanF1

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6m Campervan
Morning all,
Anyone have any experience of the Renogy combined DC to DC and MPPT?
I have fitted this and am trying to test at the moment.
The issue I'm having is that the alternator charging light (red one on the left) comes on when I plug in to EHU and then stays on even after hook up is dropped. Should only come on 15 secs after the engine is started. When I start the engine it goes out for 15 seconds then comes on again and stays on when the engine is switched off. As far as I can see the unit is charging as it should but this is annoying me.
Many thanks
Sean
 
Sorry forgot the pic
 

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Is your starter battery voltage higher than your leisure battery and its turning on the B2B?
 
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My understanding is that the red light on the left indicates that the leisure battery is fully charged and the solar panel is now charging the vehicle battery.
 
Lenny HB said:
Is your starter battery voltage higher than your leisure battery and its turning on the B2B?
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I will check but this us a good suggestion. I didn't think it would allow power through in that direction without the engine running but I guess its just based on the voltages detected?

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jp11 said:
My understanding is that the red light on the left indicates that the leisure battery is fully charged and the solar panel is now charging the vehicle battery.
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Thanks, that scenario is indicated by the red light flashing, solid red is supposed to indicate that the alternator is charging the leisure battery
 
SeanF1 said:
I will check but this us a good suggestion. I didn't think it would allow power through in that direction without the engine running but I guess its just based on the voltages detected?
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Depends on how it's wired I'm not familiar with that one, does it have a connection for the D+, if so it should only work when the alternator is running.
 
See Will Prowse on you tube he has tested this DC to DC charge, and he rates this quite well.
 
Get yourself one of these, a DC clamp meter makes it easy to see what is going on.

[Broken Link Removed]

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Lenny HB said:
Depends on how it's wired I'm not familiar with that one, does it have a connection for the D+, if so it should only work when the alternator is running.
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Thanks Lenny. It is supposed to automatically detect alternator(starter battery) voltage and come on accordingly. It also has a sensor which is supposed to be used if you have a smart alternator which I have also piggy backed to a fuse that only becomes live when the engine is switched on. I don't have a smart alternator but have connected this anyway as I have seen this suggested.
 
Lee Fryer said:
See Will Prowse on you tube he has tested this DC to DC charge, and he rates this quite well.
Click to expand...
Thanks Lee, it was his review and praise that decided me to buy it. Didn't have this problem in his review though and he charged the starter battery while the unit was connected
 
SeanF1 said:
Thanks Lenny. It is supposed to automatically detect alternator(starter battery) voltage and come on accordingly. It also has a sensor which is supposed to be used if you have a smart alternator which I have also piggy backed to a fuse that only becomes live when the engine is switched on. I don't have a smart alternator but have connected this anyway as I have seen this suggested.
Click to expand...
The problem with that is that when the starter battery rises from the solar charge it will turn on and feed a charge to the leisure battery then turn off when the starter battery falls then the cycle will start again, the same will happen when on EHU.
 
Thanks all. It appears that even 8 or so hours after unhooking from the mains, my starter battery was still sitting above 13.2 volts which made the unit think it needed to charge the leisure battery. Clearly no charging was taking place or it wouldn't still be sitting above 13.2v?
I played the radio for half an hour and the voltage dropped and the light went out.
 
Following my various posts and questions here, I have now installed the Renogy DC to DC with MPPT, two 110ah AGM batteries in parallel, Aili battery monitor and 2kwh inverter in my little Sunlight T60.
All that's left to do now is add two 100w panels to the existing one, but need the weather to warm up a bit to do that job. Space is very limited on the T60 so all the kit had to go in the space under the seats which was a challenge. The inverter is in the wardrobe which is about 2 ft from the batteries.
I have added a few pics below and would welcome any comments/criticisms/suggestions you may have.
Seems to be working as it should and was trickle charging the starter battery from solar for a little while this afternoon. With the battery at 12.7v yesterday the dcdc was giving out 35 amps briefly.

One more question if I may, I want to add a master isolating switch on the main positive lead from the leisure batteries. Is a 200 amp isolator sufficient or should I go higher?

Many thanks for all the help here. It's a great forum

Sean

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Depending on your overall set up (guess 300w of solar), this should help?
www.mobile-solarpower.com

RV Solar Power Blue Prints

Building a vehicle mounted solar power system? Let me help.
www.mobile-solarpower.com
 
I realise that this thread is 2 years old, but wondered how your DCDC60S is working now? I've installed one and my alternator light is on even with no engine running. Also the blue solar led rarely lights up. Only fitted yesterday so trying to establish if all is working!
 
growly_bear said:
I realise that this thread is 2 years old, but wondered how your DCDC60S is working now? I've installed one and my alternator light is on even with no engine running. Also the blue solar led rarely lights up. Only fitted yesterday so trying to establish if all is working!
Click to expand...
Have you connected the D+ connection correctly? It needs to go to a 12V signal which only goes on when the engine is running, so shouldn't be just connected to the ignition as that is on without the engine running, when of course the alternator is not working.

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fred_jb said:
Have you connected the D+ connection correctly? It needs to go to a 12V signal which only goes on when the engine is running, so shouldn't be just connected to the ignition as that is on without the engine running, when of course the alternator is not working.
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The alternator on my 2015 Fiat 3.0 is dumb, and according to the Renogy info it doesn't need a D+. I've noticed since posting this that once the starter battery voltage falls to 12.6 that it turns off and charging from the starter battery stops! Let's see what happens over the next few days...
 
Lenny HB said:
Get yourself one of these, a DC clamp meter makes it easy to see what is going on.

www.ebay.co.uk

UNI-T UT210E Handheld RMS AC/DC Mini Digital Clamp Meter Resistance Capacitance | eBay

Find many great new & used options and get the best deals for UNI-T UT210E Handheld RMS AC/DC Mini Digital Clamp Meter Resistance Capacitance at the best online prices at eBay! Free delivery for many products.
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Click to expand...
Hi Lenny HB this isn't available anymore. What spec should I look for? I've got a dmm ... thanks
 
This site contains affiliate links for which MHF may be compensated.
growly_bear said:
The alternator on my 2015 Fiat 3.0 is dumb, and according to the Renogy info it doesn't need a D+. I've noticed since posting this that once the starter battery voltage falls to 12.6 that it turns off and charging from the starter battery stops! Let's see what happens over the next few days...
Click to expand...
Without a D+ signal the B2B will be relying entirely on sensing the starter battery voltage to determine whether it thinks the alternator is running. I would connect the D+ signal if you have one as that takes the B2B guesswork out of the equation.
 
fred_jb said:
Without a D+ signal the B2B will be relying entirely on sensing the starter battery voltage to determine whether it thinks the alternator is running. I would connect the D+ signal if you have one as that takes the B2B guesswork out of the equation.
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I think you are right, although I did read another post where the OP was using a D+ and was getting the same as me! Why is it so difficult!!
 
growly_bear said:
I think you are right, although I did read another post where the OP was using a D+ and was getting the same as me! Why is it so difficult!!
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Yes, there is certainly a learning curve involved. I am lucky that I have a background in electronics and IT, but I have still found motorhome electrics to be a whole new can of worms!

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growly_bear said:
Ok. I'll research into 6000 4000 counts etc and min 200A...
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That will help with fault finding, but if you want ongoing info on voltages and current flow, I would recommend fitting a shunt.

I have a Renogy shunt which cost £79 and gives this info to a phone app via its built in Bluetooth transmitter. One side fits directly onto the negative leisure battery terminal with all the existing earth feeds connected to the other side. This gives you a realtime readout of incoming or outgoing current. It also has thin easily routed wires to connect to the positive side of each battery which gives a readout of voltage for both. It also has a temperature probe to report battery temperature. Great value for what it does!
 
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fred_jb said:
That will help with fault finding, but if you want ongoing info on voltages and current flow, I would recommend fitting a shunt.

I have a Renogy shunt which cost £79 and gives this info to a phone app via its built in Bluetooth transmitter. One side fits directly onto the negative leisure battery terminal with all the existing earth feeds connected to the other side. This gives you a realtime readout of incoming or outgoing current. It also has thin easily routed wires to connect to the positive side of each battery which gives a readout of voltage for both. It also has a temperature probe to report battery temperature. Great value for what it does!
Click to expand...
You know what Fred, but I've got that same shunt to fit! I bought it all in May, but with one thing and another, I've not the time to fit it all.

I've got the DCDC50S fitted to mine now, and was just wanting to see it working before I fit the shunt and lithium.
with the engine and ignition off, does your DCDC50S charge from the starter battery? (Far left hand LED lit up red) Mine does, albeit only drawing small current, until the starter battery drops to 12.6V. It seems strange to deplete charge from the starter battery.

Is yours a smart alternator?

Hoping you can help me out here!

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