Upgrading 12V system - equipment choices and compromises

[Outdoors Dad]

I like it but I'll stick with app and my wine bottle to check for tilt. We have a voltronic display for quick access to solar and battery status if we didn't that display would be perfect.

 

[fred_jb]

I'm thinking of trying to link the devices with the Renogy COM port networking gadget, though only the Core One and the B2B/MPPT controller have ports, the Shunt does not. Also though annoyingly they show an inverter very similar to mine also connected, from what I have gleaned online the current generation of inverters only support the remote control panel plug, not a data plug. It looks like there are new ones coming with a data port but I think only available in the US at the moment. Not sure if there would be any benefit if only 2 out of 4 devices can use this.

I would be interested to hear if anyone has experience with this.

 

[fred_jb]

An update on the noisy 50A Fogstar mains charger:

I replaced the 60mm fan in the unit with one linked below. It has a marginally lower flow rate of 17 cfm v 19 cfm, which I don't think is an issue, but it is so much quieter that I can now only hear it if I put my ear close to the dinette base where it is installed. Huge improvement. Should I ever experience overheating I could even fit a second fan and still have nowhere near the noise of the original.

Noctua NF-A6x25 FLX, Premium Quiet Fan, 3-Pin (60mm, Brown) https://www.amazon.co.uk/dp/B009LEKGGE?tag=mhf04-21

 

[AdrianChen]

An update on the noisy 50A Fogstar mains charger:

I replaced the 60mm fan in the unit with one linked below. It has a marginally lower flow rate of 17 cfm v 19 cfm, which I don't think is an issue, but it is so much quieter that I can now only hear it if I put my ear close to the dinette base where it is installed. Huge improvement. Should I ever experience overheating I could even fit a second fan and still have nowhere near the noise of the original.

Noctua NF-A6x25 FLX, Premium Quiet Fan, 3-Pin (60mm, Brown) https://www.amazon.co.uk/dp/B009LEKGGE?tag=mhf04-21

Noctua fans are great - have them in the last two PC's, very quiet and long lasting.

 

[fred_jb]

An update on the Renogy COM port networking device:

I found one for sale at only £20 or so, so decided to give it a go as it was fairly easy to run a couple of network cables to the Core One display and the B2B/MPPT controller, and I was quite keen to reduce reliance on Bluetooth as it can be a bit iffy, though to be fair it has all worked well on the Renogy kit.

I was concerned that as the Renogy shunt has no COM port and only has its built in Bluetooth that the system would not handle a mix of BT and COM connections. However after unpairing everything and then connecting up it all worked completely transparently. The Core One display now acts as the communications hub for the phone app and the BT-2 transmitter I had been using with the B2B is now redundant.

I get all the info I want on both the wall mounted display and the phone app, but might consider upgrading to a newer generation inverter which has a COM port at some point.

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[fred_jb]

I have now reconsidered the location of the B2B/MPPT controller. I originally had it inside the dinette seat base but it was extremely tricky to fit it in there and once in it was very inaccessible should I ever need to get at the connections and it was almost impossible to see the indicator lights on the front.

Although it was near to the Truma heater, the controller would not be running in B2B mode while parked, so would not be getting heat from that, which seems very well insulated anyway. However I noticed that when delivering the full 50A from the alternator its internal temp went up quite quickly as reported in the app. This made me wonder if despite its large heatsink it might overheat in the confined space under the seat due to limited airflow.

I decided to move it to the location under the back of the passenger seat vacated by the original Schaudt B2B, where it just fitted. The recablng was easier than I had feared and actually resulted in the high current runs (alternator input and output to leisure battery) being shorter, and the low current cables from the isolation switch I had fitted in the solar panel wiring being longer, so worth the effort.

Picture below. The voltage displays on the seat back lower panel, red for starter battery and green for the leisure battery, are a bit redundant now that I have that information in the Renogy app, but I quite like them so will be keeping them connected!

 

[Outdoors Dad]

I have now reconsidered the location of the B2B/MPPT controller. I originally had it inside the dinette seat base but it was extremely tricky to fit it in there and once in it was very inaccessible should I ever need to get at the connections and it was almost impossible to see the indicator lights on the front.

Although it was near to the Truma heater, the controller would not be running in B2B mode while parked, so would not be getting heat from that, which seems very well insulated anyway. However I noticed that when delivering the full 50A from the alternator its internal temp went up quite quickly as reported in the app. This made me wonder if despite its large heatsink it might overheat in the confined space under the seat due to limited airflow.

I decided to move it to the location under the back of the passenger seat vacated by the original Schaudt B2B, where it just fitted. The recablng was easier than I had feared and actually resulted in the high current runs (alternator input and output to leisure battery) being shorter, and the low current cables from the isolation switch I had fitted in the solar panel wiring being longer, so worth the effort.

Picture below. The voltage displays on the seat back lower panel, red for starter battery and green for the leisure battery, are a bit redundant now that I have that information in the Renogy app, but I quite like them so will be keeping them connected!

View attachment 969760

I have fitted the 30a Renogy b2b but I haven't noticed any heat. I will now monitor it to feel if it gets warm. Good info on your installation.

 

[fred_jb]

I have fitted the 30a Renogy b2b but I haven't noticed any heat. I will now monitor it to feel if it gets warm. Good info on your installation.

Glad to hear it might have been useful info!

I moved it as much for better accessibility as for better airflow, but I think heat might only be an issue if on a long drive with a fairly depleted battery. In that scenario it would potentially be pumping out 50A for several hours. I have fitted a switch in the D+ feed so I can disable the B2B function if I get any problems.

It should be less of an issue with the 30A model.

 

[Raul]

That's what I have on my b2b, an inline switch from the life signal. There are many times and scenarios where the b2b does not need to come on; specially at the peak of the summer when solar can re charge before noon. Or when you depart a campsite and been on ehu. Whats the point of having the b2b on? I have a switch in the cab with a led, to tell me if is on.

 

[fred_jb]

That's what I have on my b2b, an inline switch from the life signal. There are many times and scenarios where the b2b does not need to come on; specially at the peak of the summer when solar can re charge before noon. Or when you depart a campsite and been on ehu. Whats the point of having the b2b on? I have a switch in the cab with a led, to tell me if is on.

Yes, I think it was your earlier post that inspired me to do this. I just have a standard switch at the moment, located behind the opening door on the side of the dinette bench along with all the other switches. I thought about an LED in the cab so will maybe change to an illuminated switch in the cab.

On a different topic I have been using my newly installed kit to monitor power usage with a view to making sure that nothing not required is draining the leisure battery when the van is not being used. With everything switched off including the main 12V switch, it is down to less than 500mA which I think is probably acceptable though I would like to see it at zero!

However, today I was surprised to find that it had jumped up to 1.75 Amps. After some experimentation I found that with the EHU connected and the master mains switch on I got this extra load on the leisure battery which disappeared when the mains was switched off. By unplugging the 3000W invertor and making sure my Fogstar charger was switched off, I found that these weren't the culprits, so it is down to the EBL31. If I switch power to the EBL off via the RCD which powers it, the extra load disappears.

I find it very puzzling why connecting mains to the EBL should cause any extra load on the 12V supply from the leisure battery, so any thoughts on this would be welcome!

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[Outdoors Dad]

Does the EBL need a small amount of power to work?

 

[fred_jb]

Does the EBL need a small amount of power to work?

Yes I'm sure it does, but what I don't understand is why the current used becomes much greater when mains is connected to the EBL as it doesn't need a mains connection to work and works perfectly well when not on an EHU.

As far as I know it only uses mains, when available, for powering its internal battery charger. It will use the mains power to trickle charger the starter battery and provide about 20A to the leisure battery, though in my case I have removed the 20A fuse as I have an alternative lithium friendly charger.

 

[Gromett]

Seems like an appropriate thread

If you don't have your multimeter and need to test a fuse.

 

[Raul]

Quiescent draw is hard to trace. Only way you'll find out is with a clamp meter on every wire that's connected to EBL, if that's where the power goes.
My constant load is 19-22w, that's monitoring and all gubbins to stay alive. Most of that, is the router.

 

[fred_jb]

Quiescent draw is hard to trace. Only way you'll find out is with a clamp meter on every wire that's connected to EBL, if that's where the power goes.
My constant load is 19-22w, that's monitoring and all gubbins to stay alive. Most of that, is the router.

Having given this some more thought, I can only conclude that the additional current taken when the EBL mains input is live must be internal to the EBL because nothing external changes. The 12V output to most consumers is switched off, and those 12V outputs that stay live, such as the step and the frost dump valve are not changing their state.

I suspect the internal circuitry that manages the charging is not self powered from the mains as I might have expected, but from the 12V supply. I suppose in the normal course of events, with the EBL charger putting out about 20A to the battery it is still very much a net positive flow to the battery, so this would not matter.

I guess it is only now that I have partially disabled the EBL, by removing the 20A fuse to prevent it charging the new lithium leisure battery, that this power consumption is revealed. This might be something to be considered for others who have done the same. I have only left the EBL charger live when on EHU so that it can trickle charge the starter battery, but I have an Ablemail unit which can keep the starter battery charged from the leisure battery, so maybe I will try just fully disabling the EBL by removing its mains supply and see how it goes.

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[fred_jb]

A couple of small updates on this project in case they are of interest:

I decided to completely disconnect my EBL from the mains. I had already disabled the leisure battery charging but found that just having mains connected caused a drain of about 1.25 amps from the12V supply, presumably used by the mains control circuitry in the EBL.

This meant I also lost the trickle charging of the starter battery. Although I have an Ablemail unit which can trickle charge from the leisure battery I decided to install a small dedicated 1A mains charger for the starter battery. This takes up very little space and is powered from the same mains circuit as the Fogstar lithium charger.

I also lost the mains indicator light on the LT100 panel that the EBL connects too, but reinstated that with a little mains to LED driver adapter plus a couple of diodes and resistors.

The other little mod may be of interest if you decide to use the Renogy Shunt 300, as I have. I have the other Renogy kit, One Core display and DC-DC, connected by hard wiring to a Renogy data port hub, but the shunt does not have a port for this so relies on Bluetooth connectivity which as I'm sure many people have found, can be a bit flakey.

I had some problems getting it to connect originally, and eventually woke it up with its reset button. I then changed the app over to a different phone which required setting everything up from scratch again and had the same problem, but this time the reset button had no effect. I decided that the shunt must be powered from the B1 sense wire which connects to the leisure battery +ve, so tried disconnecting that to power down the unit fully.

This worked, so as the shunt is not terribly easy to get at and the B1 terminal is very difficult to insert the wire into, I decided to put a switch into that wire so that I can easily reset the shunt remotely in future. I would strongly recommend anyone installing the Renogy shunt to do the same.

 

[Insider]

Interesting thread for me as although I've different kit for the most part the principles are the same and I hadn't got round to looking at what fuse I'll put between my 2000W renogy and lithium. Thanks x2 Fred