Help with BTB Charger wiring please. (1 Viewer)

[Revolvor]

I have posted a few times about my desire to install Solar and a BTB charger, and have nearly decided what to do.

I will have a dedicated Solar Charge Controller, connected to the Leisure Battery, and not make use of the existing wiring from the EC225. Would I still need a "Battery Master" if I have a BTB Charger? Will the two work together?

However, I am still not sure how to modify the wiring to allow a BTB charger to work correctly.

I sent the following to Sargent Tech Support, but have had no reply.

Is anyone on the forum able to help?

"I have a 2008 Autotrail Excel 600B, fitted with a Sargent EC225 Power Supply and EC100 Control Panel.
I wish to add a “Battery-to-Battery” charger, to enable quicker/more efficient (4-stage) charging of the leisure battery when it is being charged by the Alternator.
In order for the BTB charger to work, I will need to remove the existing input from the Alternator to the leisure battery. I assume this is controlled by some sort of split-charge or voltage-sensing relay, but may also go through the EC225.
However, I will still want there to be a 12v supply to the fridge when the engine is running, and also for the Leisure Battery to charge, via the EC225, when on EHU. I assume that the EC225 also needs a signal to switch-off the 12v supplies (lights/sockets etc) when the engine is running, to comply with regulations.
Are you able to advise me of the modifications to the wiring that I will need to make to enable the BTB charger to work correctly? Are you able to supply any wiring diagrams – more comprehensive than the one in the EC225 Instructions?"

Thanks,
John

 

[Abacist]

I am surprised that you expect a firm like Sargent to attempt to supply what you want to someone who obviously does not know what they are doing and presumably for free! If they tell you to do X, Y and then Z and you electrocute yourself, burn your van to the ground or blow a battery up they would be putting themselves at risk of a claim from you or your insurers. Think about it, how are they supposed to know if your van has already been tampered with such that it is no longer standard.

I have learnt enough from this forum to know that I don't know much about 12 volt electrics and the potential to cause a bad fire is great. Why risk one of your biggest investments? Get someone who knows what they are doing to do it and pay for the peace of mind!

 

[DavidG58]

tough but true, 'cruel to be kind' and all that, not just this OP but I see loads of questions for advice that IMO they are not proficient to undertake

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[andy63]

Hi John. .as far as I know there is no conflict in installing the btb charger and battery master.
The btb charger will ensure efficient charging of the leisure battery from the alternator and a device like the battery master will ensure a trickle charge to the start battery once the leisure battery voltage reaches a predetermined voltage regardless of the charging source .ie solar ,alternator or mains charger..
In your letter to sergeant you mention removing the existing wiring from alternator to leisure battery..again I think that that wiring will have nothing to do with the sergeant unit as I think that only deals with charging the leisure and start batteries from a mains source and not via the alternator ,so if that wiring is in place it's been added and may be via a voltage sensing relay and a btb would be a more effecient option..
I've looked at the Stirling btb charger wiring dig and looks straight fwd.ie basically connecting the two sets of batteries together via the btb unit..
I have fitted a few battery master devices and they are straight forward and simple..
Hope someone can give you a bit more help with the battery to battery charger
Ta Andy.

 

[dave newell]

If you use a CTEK D250S Dual it will solve all your problems. It is a MPPT solar regulator AND B2B charger in one unit, it also splits the solar charging between leisure and engine batteries.

D.

 

[Techno]

Very interesting and educational video


Antipodean demo

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[Techno]

The only thing I cannot ascertain is how much solar it can handle?
Price is very good
Broken Link Removed

 

[Techno]

Even the user manual does not specify the solar capacity.
I doubt it will perform as well as my dedicated mppt regulator but still impressive kit and a no brainer if starting from scratch. Also a no brainer compared to sterling and their prices.
http://www.ctek.com/Archive/ProductManualPdf/SMARTPASS_EN.pdf

 

[Techno]

I'm tempted to sell my Elecsols

and replace with four of these although I have room for 5
Broken Link Removed

Perfect fit in my gas locker and easy to drill through into the double floor cavity to link the two sets of two

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[Techno]

double post

 

[Techno]

Roadpro are a high price seller but they are the only outlet actually quoting a maximum solar output as 340 watts. Where they got that info I don't know? but it does show it is suitable for me if I want to play.
Broken Link Removed

 

[TheCaller]

The only thing I cannot ascertain is how much solar it can handle?

It's rated as a 20A charger, so I suppose that's the practical maximum. They recommend a 30A fuse in the solar panel supply cable. Multiple panels must be connected in parallel because it's maximum input voltage is 23V.

It's a cracking bit of kit. Ideal if you are starting from scratch & so straight forward compared to most alternatives.

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[Techno]

It's rated as a 20A charger, so I suppose that's the practical maximum. They recommend a 30A fuse in the solar panel supply cable. Multiple panels must be connected in parallel because it's maximum input voltage is 23V.

It's a cracking bit of kit. Ideal if you are starting from scratch & so straight forward compared to most alternatives.

That just backs up my assumption that it is not as efficient as a dedicated MPPT as my own has exceeded 22 amps from 300 watts. I still question where roadpro got a figure of 340 watts when it is not in the user manual

 

[dave newell]

I'm fairly certain the 20A figure is the B2B rate (increased by using the smartpass unit alongside). Having since checked it is indeed quoted as 20 Amps charging current, safe to assume this is for both B2B and solar functions but while Andy's setup may exceed this level many users setups will not.

D.

 

[Techno]

Yes I agree. I believe the solar is rendered open circuit with the engine running.

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[dave newell]

Yes I agree. I believe the solar is rendered open circuit with the engine running.

Dunno mate but I know it works well as I've been using one on our camper for a couple of years with no problems and no flat batteries.

D.

 

[Revolvor]

Well …. two very different tones in replies to my post! Firstly thanks to the constructive replies from @Techno100, @dave newell lvs and @andy63.

@Abacist – not sure what sparked that off! There are 100’s of posts on this forum from people that “do not know what they are doing” … that’s why they posted the questions. There are also 100’s of posts promoting the idea of DIY projects such as fitting Solar Panels and more. The fact that some of the professionals on the forum such as Techno100, Dave Newell and Eddie Vanbitz are prepared to give technical advice suggests that even they agree that some projects are practical with good DIY skills.

I joined the forum a year ago and have learnt so much from the posts by members. Since then I have learned about the difference between MPPT and PMR solar controllers, Battery-to Battery charging, 4-stage charging of 12v batteries, best practice for location of fuses, wire gauges and much much more.

A good way to learn about a subject is to ask others with experience, and that is what I am doing. Just for the record, official Autotrail advice is to contact Sargent for issues with wiring. Over the past year I have had a number of email exchanges with the technical department at Sargent, and they have been extremely helpful with advice on technical matters, one being fitting solar panels, which they do not supply.

I am a professional engineer, with I believe a deal of common sense, and have no intention of compromising the wiring of my motorhome. By asking questions I was trying to get the information to decide whether what I wanted to do was practical for me to perform, or if I should seek professional help.

John

 

[Techno]

I learned plenty too thanks to @dave newell lvs
I was not familiar with the CTEK range and I'm quite impressed.

Prices vary wildly but even list prices are good

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[Techno]

I've found the D250S @ £169 and the Smartpass @ £136 inc delivery so only £305 for the set.

Also the MXS 25 Charger @£173 for 500ah battery banks

 

[andy63]

Well …. two very different tones in replies to my post! Firstly thanks to the constructive replies from @Techno100, @dave newell lvs and @andy63.

@Abacist – not sure what sparked that off! There are 100’s of posts on this forum from people that “do not know what they are doing” … that’s why they posted the questions. There are also 100’s of posts promoting the idea of DIY projects such as fitting Solar Panels and more. The fact that some of the professionals on the forum such as Techno100, Dave Newell and Eddie Vanbitz are prepared to give technical advice suggests that even they agree that some projects are practical with good DIY skills.

I joined the forum a year ago and have learnt so much from the posts by members. Since then I have learned about the difference between MPPT and PMR solar controllers, Battery-to Battery charging, 4-stage charging of 12v batteries, best practice for location of fuses, wire gauges and much much more.

A good way to learn about a subject is to ask others with experience, and that is what I am doing. Just for the record, official Autotrail advice is to contact Sargent for issues with wiring. Over the past year I have had a number of email exchanges with the technical department at Sargent, and they have been extremely helpful with advice on technical matters, one being fitting solar panels, which they do not supply.

I am a professional engineer, with I believe a deal of common sense, and have no intention of compromising the wiring of my motorhome. By asking questions I was trying to get the information to decide whether what I wanted to do was practical for me to perform, or if I should seek professional help.

John

Couldn't agree more with your thoughts..
At the end of day it's work on your own van and if you are prepared to have a go with help available then that's how you learn..
I've made mistakes but generally if the right information is available and you are prepared to take time and make the effort you get there..
Andy

 

[dave newell]

I learned plenty too thanks to @dave newell lvs
I was not familiar with the CTEK range and I'm quite impressed.

Prices vary wildly but even list prices are good

You flatter me sir ;-) . I don't use the smartpass myself just the D250S and that has coped well for our needs and considering we use a power hungry compressor fridge I feel the D250S Dual has earned my respect. In fact I personally prefer CTEK kit to Sterling, its well made, compact and just works efficiently plus its cheaper. I have an earlier D250S on the work Ducato feeding two 110AH batteries in the rear for powering a couple of lights and a small Sterling inverter for charging my drill batteries plus eventually I may fit an Eberspacher heater I have lying around. I have the 25 Amp mains charger on the camper plus another one in the workshop, great piece of kit that just works.

D.

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[Don Quixote]

I've found the D250S @ £169 and the Smartpass @ £136 inc delivery so only £305 for the set.

Also the MXS 25 Charger @£173 for 500ah battery banks

Andy, I have this charger and 2/3 times a year use it on the bank of batteries and the vehicle battery just to condition them. Great bit of kit and always carry it in MH and have loaned it it a few times to others to condition their batteries.

 

[premiere99]

I have been using a pair of Ctek XS 3600 chargers (4 step 3.6A) wired across the engine battery which also charges the Leisure batteries via the Merlin M-Power Voltage Sensitive Relay but lust after a MXS 25 8 step charger. I decided that Ctek was safer than the Sargent charger as I did not like the idea of pumping 18+ Volts into everything that is connected to the batteries when the Sargent charger was switched on.

 

[Abacist]

Well …. two very different tones in replies to my post! Firstly thanks to the constructive replies from @Techno100, @dave newell lvs and @andy63.

@Abacist – not sure what sparked that off! There are 100’s of posts on this forum from people that “do not know what they are doing” … that’s why they posted the questions. There are also 100’s of posts promoting the idea of DIY projects such as fitting Solar Panels and more. The fact that some of the professionals on the forum such as Techno100, Dave Newell and Eddie Vanbitz are prepared to give technical advice suggests that even they agree that some projects are practical with good DIY skills.

I joined the forum a year ago and have learnt so much from the posts by members. Since then I have learned about the difference between MPPT and PMR solar controllers, Battery-to Battery charging, 4-stage charging of 12v batteries, best practice for location of fuses, wire gauges and much much more.

A good way to learn about a subject is to ask others with experience, and that is what I am doing. Just for the record, official Autotrail advice is to contact Sargent for issues with wiring. Over the past year I have had a number of email exchanges with the technical department at Sargent, and they have been extremely helpful with advice on technical matters, one being fitting solar panels, which they do not supply.

I am a professional engineer, with I believe a deal of common sense, and have no intention of compromising the wiring of my motorhome. By asking questions I was trying to get the information to decide whether what I wanted to do was practical for me to perform, or if I should seek professional help.

John

John I don't disagree with the above and perhaps was rather terse in my original post for which I apologise.

At the first reading of your original post I thought your request to Sargent was excessive and beyond reasonable requesting diagrams and suggestions as to how to wire your proposals. Hence my suggested explanation as to why they had not replied.

Still I suppose "nothing ventured nothing gained" and not for me to interfere!

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[TheCaller]

That just backs up my assumption that it is not as efficient as a dedicated MPPT

I'm sure that a dedicated MPPT controller from one of the top class manufacturers would be a more capable unit, but the CTEK is the ideal 'fit & forget' solution for the needs of the average user. It wouldn't work for you & for different reasons it doesn't work for me, but I've recommended it to my mate down the road who is doing his own van conversion - it's an ideal unit for his needs. I was going to put one in my VW camper, but we changed our plans & bought the Campscout, which already has an Electrobloc installed.

As solar panels get cheaper & more popular, I won't be surprised if CTEK introduce an uprated model before long.

 

[Revolvor]

John I don't disagree with the above and perhaps was rather terse in my original post for which I apologise.

At the first reading of your original post I thought your request to Sargent was excessive and beyond reasonable requesting diagrams and suggestions as to how to wire your proposals. Hence my suggested explanation as to why they had not replied.

Still I suppose "nothing ventured nothing gained" and not for me to interfere!

@Abacist, Thanks for your reply – apology accepted! Maybe I over-reacted too!
You are probably right that I was being a bit optimistic to expect Sargent to answer my question, but as you say … “nothing ventured, nothing gained”. This forum is a valuable resource, and I am sure we will all continue to learn from others.

Regards,
John

 

[PhilandMena]

Suggest you touch base with Sergeant again. I have a 2011 Autotrail and they told me the B2B charger was not compatable with my system.

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[Revolvor]

Suggest you touch base with Sergeant again. I have a 2011 Autotrail and they told me the B2B charger was not compatable with my system.

I was beginning to think that! I spent a lot of time over the weekend tracing the wiring to and from the leisure battery, and the Sargent EC225 seems to play a part in the link from the Van to Leisure batteries.....nothing as simple as a split-charge relay! I think I will have to forgo the BTB Charger option and just go for a Solar Panel with an independent Solar MPPT controller and a Battery Master.
John

 

[PhilandMena]

I would still talk to Sargent as my Excel is 3 years older than yours and has the EC500 P.S.U. with EC300 control panel. I am impressed with the Sargent electrics on my Motorhome. There was even a Solar Panel controller wired into the P.S.U. should a S.P. be fitted later, as I did.
My P.S.U. also has a 3 stage battery charger and automatically switched from leisure battery to cab battery as required, as does my S.P.
I'm not familiar with your set up but Sargent will advise if it's a straight forward question.

 

[andy63]

I was beginning to think that! I spent a lot of time over the weekend tracing the wiring to and from the leisure battery, and the Sargent EC225 seems to play a part in the link from the Van to Leisure batteries.....nothing as simple as a split-charge relay! I think I will have to forgo the BTB Charger option and just go for a Solar Panel with an independent Solar MPPT controller and a Battery Master.
John

Hi John, what problems do you see in installing a battery to battery..
To me it would just be another charging source, ie from alternator.. and I can't think how that would interfere with the sergeant. ..
I've read @PhilandMena post above about Sargent not been compatible with his ..I'm sure they could say why and what the issues are...
Obviously you need to be sure but I can't think why not..
Ta Andy

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