B2B victron in Adria

[Cliff Bryant]

Ok, thanks for the replies, looks like I'll have to find a way to disable the split charge relay.

This is all a bit moot as the OP asked the question in Mar 2022.

However I concur, you do need to disable the split charge relay action but that doesn't mean having to modify the NE237. I added a normally closed contactor with a low voltage schottky diode (an ideal diode would have been better possibly) across the terminals. When the engine is running the contactor operates and breaks the circuit. The diode across the contacts is reverse biased and so blocks any charge from the alternator. If the engine is switched off the contactor closes again and connects the habs battery to the engine battery via the NE237. It's necessary to retain the normal engine battery/alternator connection to the NE237 due to the way the fridge is wired. Other electroblocks have a separate connection for the fridge circuit but the NE237 has all the switching and wiring internal, fed from the main battery/alternator feed.

During my modifications (lockdown 2020) I also installed a Sterling inverter/charger and a 100Ah KS Energy Lithium battery. I separated the mains feeds inside the consumer unit so the fridge and truma heater are not connected to the Sterling output. The result is that if I turn the inverter on it feeds mains to all the 230V sockets in the van but not the fridge and truma. As the Sterling has an EHU changeover switch it automatically switches the sockets to EHU power if present. As the Sterling also charges the habs battery (and vehicle battery if you add the extra module) I removed fuse F7 from the NE237 to disconnect the internal charger. The lithium habs battery is charged by the Sterling at around 45A. The Sterling has the correct Lithium charging profile whereas the NE237 does not support Lithium. Having designed Lithium battery chargers professionally I caution against just selecting Gel or AGM of whatever. It will likely charge the battery if the volts are high enough but you rely heavily on the BMS inside the battery to protect against overcharging.

The Victron B2B charges at 30A maximum which means in practice the battery is 80% charged in less than a hour after a typical, off grid, overnight stop. In the summer months (when we mainly use it) the whole system is kept pretty much charged by the 230W of solar power on the roof. A friend has installed a 200Ah battery system in his van with some 430W of solar and he can pretty much run his fridge during daylight hours from the solar alone. I use gas for my fridge when parked up. I may add extra solar at some point.

All of my modifications are very easy to remove when I sell the van. I picked the Sterling unit over a Victron as the Sterling unit was the only one I could find that would physically fit in the electrics area. I also have a Victron MPPT charger as well as their B2B. It all works very well, I was even complimented on the quality of the installation by the Adria dealer's engineers! The van is an Adria Matrix 670SC for the record.

Hope this is of interest/use to someone!

 

[Cliff Bryant]

Personally I would avoid any device that needs active cooling. The Stirling B2B units have fans built in. They work OK but get noisy. (The 30A B2B only provides 25A at best).
Introducing any mechanical moving parts item into a electrical system introduces reliability issues.
Devices with correctly designed passive cooling will be best.

I also would prefer not to use active cooling but DC-DC converters will have a maximum efficiency meaning some heat will be inevitably be produced at the powers involved. Passive cooling is not always possible. Consider that the electric compartment of a typical van is not well ventilated and then consider the 40C summer (ambient) we experienced in France last year, it would be quite an ask to provide passive cooling to deal with that.
I disagree with your statement that the 30A will produce 25A at best. My installation monitors current into the battery and I see 30A as per specification from the replacement Victron unit, the first one did derate when hot.

 

[treblid]

I disagree with your statement that the 30A will produce 25A at best

I was talking about the Stirling 30A B2B.
The Victron is a much better unit in my opinion and silent.

 

[Cliff Bryant]

I was talking about the Stirling 30A B2B.
The Victron is a much better unit in my opinion and silent.

My mistake, thanks for the clarification.

 

[Pausim]

I think you are are going to cause dangerous problems if people follow that over simplified diagram. You need to show the 12V distribution control box!

It is a simple diagram to explain the loop caused by a split charge relay when left alongside a B2B. I have deliberately not shown the detailed wiring. The relay is shown on its own because this is not always incorporated within the the 12V distribution box. What dangerous problems will it cause?

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[treblid]

t is a simple diagram to explain the loop caused by a split charge relay when left alongside a B2B

My apologies, I misread your original description with the diagram. I thought the relay shown was the relay you added.

Do you have any issues with the timings (relay response times) of the 2 relays? Ideally you would want your relay (green star) to open before the split charge relay closes.

 

[Pausim]

My apologies, I misread your original description with the diagram. I thought the relay shown was the relay you added.

Do you have any issues with the timings (relay response times) of the 2 relays? Ideally you would want your relay (green star) to open before the split charge relay closes.

I haven’t noticed any issues. There could be a moment before the loop is broken but I don’t think this would cause a problem.

 

[Garry - June]

I have installed 2x Lithiums in my van and they have been working brilliantly for 8 mths now... I have not felt the need to fit a B2B and after reading all the comments here I don't think I will be either..

 

[TR5]

What actually governs the charge supplied via a split charge relay - is it literally the cable size / relay capacity, or am I thinking wrongly?

 

[Lenny HB]

What actually governs the charge supplied via a split charge relay - is it literally the cable size / relay capacity, or am I thinking wrongly?

Yes that's what happens but Lithium are capable of charging at 100 - 200 amps so you either burn out your wiring or you fit heavy cables and burn out your alternator.
A B2B will control the charge rate.

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[TR5]

Yes that's what happens but Lithium are capable of charging at 100 - 200 amps so you either burn out your wiring or you fit heavy cables and burn out your alternator.
A B2B will control the charge rate.

So if you have a split charge relay set-up for wet lead acid batteries, you could just enlarge the cable and relay capacity, to get more charge into the leisures. Or fit an additional relay activated by the alternator running, and run a live from the vehicle to the leisures. Is it that simple?

 

[Cliff Bryant]

So if you have a split charge relay set-up for wet lead acid batteries, you could just enlarge the cable and relay capacity, to get more charge into the leisures. Or fit an additional relay activated by the alternator running, and run a live from the vehicle to the leisures. Is it that simple?

Lead acid batteries can only charge at a maximum of, typically, 0.2C but 0.1C is the usual current. This equates to 10A max for a 100Ah battery. Part of the reason for this is to stop the battery 'gassing' (hydrogen is produced) and part is simply the chemistry. So if you increase the wire thickness and decrease the wire resistance you won't really improve the charge rate. You would also need to set the voltage level to vary the charge current, modern smart alternators will fight you in this respect hence the use of B2Bs. Lithium batteries on the other hand can charge a 1C, I.E. 100A for a 100Ah battery although I personally limit mine to charging at 50A or 0.5C. Lead acid chemistries shouldn't be discharged below 50% as it will reduce the battery lifetime and in some cases warp the plates. Lithium can be discharged to 0% although 10% or 20% is normally used to extend the life of the batteries.

 

[MisterB]

This is all a bit moot as the OP asked the question in Mar 2022.

However I concur, you do need to disable the split charge relay action but that doesn't mean having to modify the NE237. I added a normally closed contactor with a low voltage schottky diode (an ideal diode would have been better possibly) across the terminals. When the engine is running the contactor operates and breaks the circuit. The diode across the contacts is reverse biased and so blocks any charge from the alternator. If the engine is switched off the contactor closes again and connects the habs battery to the engine battery via the NE237. It's necessary to retain the normal engine battery/alternator connection to the NE237 due to the way the fridge is wired. Other electroblocks have a separate connection for the fridge circuit but the NE237 has all the switching and wiring internal, fed from the main battery/alternator feed.

During my modifications (lockdown 2020) I also installed a Sterling inverter/charger and a 100Ah KS Energy Lithium battery. I separated the mains feeds inside the consumer unit so the fridge and truma heater are not connected to the Sterling output. The result is that if I turn the inverter on it feeds mains to all the 230V sockets in the van but not the fridge and truma. As the Sterling has an EHU changeover switch it automatically switches the sockets to EHU power if present. As the Sterling also charges the habs battery (and vehicle battery if you add the extra module) I removed fuse F7 from the NE237 to disconnect the internal charger. The lithium habs battery is charged by the Sterling at around 45A. The Sterling has the correct Lithium charging profile whereas the NE237 does not support Lithium. Having designed Lithium battery chargers professionally I caution against just selecting Gel or AGM of whatever. It will likely charge the battery if the volts are high enough but you rely heavily on the BMS inside the battery to protect against overcharging.

The Victron B2B charges at 30A maximum which means in practice the battery is 80% charged in less than a hour after a typical, off grid, overnight stop. In the summer months (when we mainly use it) the whole system is kept pretty much charged by the 230W of solar power on the roof. A friend has installed a 200Ah battery system in his van with some 430W of solar and he can pretty much run his fridge during daylight hours from the solar alone. I use gas for my fridge when parked up. I may add extra solar at some point.

All of my modifications are very easy to remove when I sell the van. I picked the Sterling unit over a Victron as the Sterling unit was the only one I could find that would physically fit in the electrics area. I also have a Victron MPPT charger as well as their B2B. It all works very well, I was even complimented on the quality of the installation by the Adria dealer's engineers! The van is an Adria Matrix 670SC for the record.

Hope this is of interest/use to someone!

Thanks for the information. I need to do as you have done in order to get my Renogy 60Ah DC to DC charger to work correctly. I also have an Adria Matrix 670 (SLT) with the NE237 so I assume the changes would work for my situation aswell.

I'm reasonably practical and can follow instructions, so if you're happy to guide me along the process that would be great, or I could even pay you to install ??

Where are you based if you don't mind me taking a look at the modification please?

Thanks

Happy to move this to a private conversation to protect any personal information

 

[Tude]

I recently upgraded my ih to a b2b & lithium, and already having a victron solar controller and battery monitor it made perfect sense to use a Victron B2B too.

But, Victron only do a 30A B2B, which I thought was rather low for a single 110ah battery, so I went with an isolated Votronic 45A B2B instead - really impressed with the quality

Ecotree 110A lithium & B2B install 2008 ih Fiat PVC

Guys, I was another lucky recipient of the half price offer Ecotree lithium battery deal and, as I'd been preparing my vehicle over the last few year's to make the jump to lithium it couldn't of been timed any better. As a bit of background, we bought our van in summer 2019 and found out...

www.motorhomefun.co.uk

Victron do a 50amp dc to dc

 

[BlackIce]

JLooking for some help if possible I want to fit a B2B victron charger into my Adria Matrix 670sl to feed my two 110amp leisure batteries, unfortunately at this moment I don't have lithium batteries, I have watched various videos on you tube so I know how to fit the unit , but no one can say if I need to alter the main control box or is it just a install and ready to go , can anyone help

Hi,
I fitted the new 50A victron B2B as part of a lithium upgrade.
The main thing is to disable/remove your existing split charge relay.
The process is then very simple.Although you probably won't be drawing 50A for your existing batteries I would use heavy 25mm cable so it would be OK if you go to lithium in the future.
When you have it connected via Bluetooth choose altenator type (smart/standard) and charging battery type (lead acid).
I would definitely choose the new 50A as it runs cool and is much smaller than the old 30A unit. If your altenator isn't up to supplying 50A you can reduce the output to what you want in the settings.
Hope this helps.

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[Bobby-gg]

Victron do a 50amp dc to dc

They do now, but not when I did my installation, otherwise, I would have installed Victron!!!!