One For The Techies Amongst Us B2b Competing With Solar Etc (1 Viewer)

[jonandshell]

I'm thinking of fitting an Alt2B charger instead of the B2B. Anyone any experience with these?

Dick

Yes. They are great!
Only if you like a big job and have a big juicy battery bank to benefit though!
I see 90 amps at tick over into the 345Ah traction battery. This rises to 120 amps at 1200 rpm.
We have a proper van with a proper 150 amp alternator!
Transits rule!

 

[Don Quixote]

Well since June 2015 it's all working as my old posts state, I'm changing nothing in my MH.

 

[Techno]

While I'm on hook up my solar batteries have a self installed mains charger
My mppt will interrogate the voltage every minute and pulse a couple of amps at them for a few seconds before standing down
It does not compete

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[Reallyretired]

I don't have a b2b so my system is a lot simpler. On ehu the leisure battery voltage is high enough for the solar controller to shut down. In normal driving with fridge on 12v the pathetic bit of charge from the alternator is not enough to do this so the solar charges the batteries, if the sun is shining that is.
My view is that as long as the batteries are fully charged I'm not that bothered where it comes from.

 

[EssexBoy]

My view is that as long as the batteries are fully charged I'm not that bothered where it comes from.

I agree 100% with that...

My only concern as a mostly non-EHU user is how do I ensure that the biggest output charger is working at all times??...
for instance, after a few cloudy days, will the low hab batteries get the full B2B output when the engine is started, over-riding the ongoing low charge from the solars?

 

[Techno]

Solar regulator will switch off when it sees 14.4 volts from the engine

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[EssexBoy]

Solar regulator will switch off when it sees 14.4 volts from the engine

Thanks Andy...

But in my example, wouldn't the solar be already putting out 14.4V also, but just a few Ah as the batteries are low & and its cloudy?

ie the B2B doesn't engage as it already sees the batteries being charged, but what it can't see is that it could do better

EDIT: I guess the real answer is to test it... I have the same mppt as you, so in my case, I think the B2B would take precedence, just like your mains charger did...

 

[Techno]

B2b will put out 14.4 volts no matter what certainly long enough for the solar regulator to wind it's neck in and then the b2b will stay in control

 

[Wildman]

Eddie I rely soley on solar 365 and apart from snow never had a problem. No hook up and during the winter van is static so only solar yet the TV etc is used for 3-6 hours a day.

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[Techno]

My favourite multimeter with with DC current measurement up to 100 amps
Easiest way to evidence what is going on

 

[Gromett]

I had forgotten about this thread. The middle of last year I bought Sterling 50 amp charger for my setup. But before this I had a 25Amp Amperor.
When on mains hookup after a long time off, the Amperor charger would kick in 25 amps and when the voltage rose to a certain level it would start buzzing and the buzzing would pulse. I got a bit concerned about this and after it happened a few times always at the same voltage I hit and held the reset switch on the solar charger. This stopped the buzzing. They were definitely competing at that particular voltage. It wasn't serious enough for me to worry about it as I was on hookup and the meter told me I was getting the expected amperage going into the batteries.

However if a similar thing happens between the B2B and the Solar then the B2B will not be as effective as it could be. My next rewire is about to happen and I will be putting some kind of switching back in the solar panel side....

 

[hilldweller]

B2b will put out 14.4 volts no matter what certainly long enough for the solar regulator to wind it's neck in and then the b2b will stay in control

If any other charger is outputting 14.5V or more no current can flow from the B2B. But this is near charged voltage, if the batteries are low the low current chargers will not have enough amps to raise the voltage and B2B brute force should win.

But at the end point it's all up for grabs and as Gromet has just reported, they can and will interact.

I have mains, solar and alternator all connected and no obvious problems over a few years.

There seems to be a market here for a multiple input current summing switcher. Not that far off the B2B sucking the alternator dry by trickery.

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[Techno]

Why would any other charger put out a higher voltage
The cheap ones tend to not go over 13.6 and the dear ones just like the sterling b2b will deliver according to the battery type selected which is 14.8 for wet batteries

 

[Techno]

Also a solar regulator cannot deliver a constant voltage as it depends on the sky and the moment it dips it's out of the game

 

[tonyidle]

I'm pretty sure that the only way to obtain 'technically correct' charging would be to have one control charger accepting multiple inputs or multiple chargers controlled by a master. And the only way you'll come close to this is to scrap everything you have and purchase the replacement system from one trusted source. If you were to do that you would have to re-wire the entire leisure distribution system in line with accepted standards because I haven't come across a motorhome or caravan wired correctly yet.

So my original answer stands: no charger will 'fight' with another; they won't fully co-operate either but, as in life, the most powerful at any given time will do the work.

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[Techno]

Yes the CTEK dual and smart pass will do that
Also it integrates with any CTEK mains charger

 

[hilldweller]

Also a solar regulator cannot deliver a constant voltage as it depends on the sky and the moment it dips it's out of the game

Why would any other charger put out a higher voltage

Neither you nor I know what someone plugs in and what voltage it will output.

Good point with solar dipping, so when it comes up again it may pass the B2B voltage, that could turn off the B2B but quickly the volts drops again because the solar can't pass enough amps so B2B turn on and the system oscillates.

Not ideal but no-one is going to pay for an industrial grade solution.

We've been seeing acres of wind and solar here in Spain, one panel must have been about 100 feet square. They not only have to get the voltage spot on but in phase, so given the cash all can be solved.

 

[Techno]

Non of that happens with mine. Have you evidenced this with meter or just speculating?
It should not come back up again as you say as it will see the constant voltage from the B2B and certainly not go to a higher voltage than design or you should bin it.

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[Neckender]

I have recently installed a 20 amp Sterling B to B to our 2014 Auto Sleeper Broadway fitted with 90 watt of solar through Sargent EC500 psu.
I emailed sterling as I was concerned about the above issues and this is the reply I got from Charles Sterling.

John.


Hi John,

Simply connect the BBW from the starter battery to the leisure battery.

Bypassing the sargent unit shall not be an issue.

A complete rewiring is not necessary, just keep it simple.

Thank you for your inquiry,

Charles Sterling Junior

 

[Techno]

BTW for anyone watching! The mppt regulator that I've favoured for some years now is being shipped from Germany rather than Taiwan as originally (came to light recently in another thread) That means no fear of additional charges of import duty and VAT or Parcelfarce interference . So now the prices for either the 200watt or 300watt are extremely attractive

 

[Techno]

This is the unit @dave newell lvs uses
http://www.ebay.co.uk/itm/191529611667?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

And here with smartpass

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[hilldweller]

Non of that happens with mine. Have you evidenced this with meter or just speculating?

Just tossing ideas around as was the original request.

 

[hilldweller]

This is the unit
And here with smartpass

It's a pity something pretty clever is packaged in such an amateurish/stylish crappy plastic box. It looks like something from Lidl rather than proper job. They should have called you in to make it look right.

 

[dave newell]

It's a pity something pretty clever is packaged in such an amateurish/stylish crappy plastic box. It looks like something from Lidl rather than proper job. They should have called you in to make it look right.

I disagree with the style/looks comment but I do think the connections leave a bit to be desired as they leave exposed metal parts which are live(+12V) on two of them. The casings are robust and made for the job, plus the Ctek unit is about 1/3rd the size of the Sterling which I have always thought looked a bit industrial.

One major advantage of this unit is that as it handles both solar and split charging in one unit there are no contention issues between the two means of charging plus the solar part is MPPT.

D.

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[Techno]

Ahh but Dave, the IP68 (edited)solid state Sterling is much smaller than the old heavy cast aluminium heat sunk job

 

[Techno]

 

[Techno]

CTEK seem to use the same basic mould for all their top end units
I'm quite happy with the 25amp service charger and power supply and easily switch it between my two 500ah battery banks for recon charging

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[dave newell]

Ahh but Dave, the IP68 (edited)solid state Sterling is much smaller than the old heavy cast aluminium heat sunk job

Fair point Andy, but then neither of them are intended to be on full view all of the time. I'm fairly certain that they are intended/expected to be fitted in hidden areas, out of plain view so general appearance doesn't really matter that much. My only gripe with the CTEK units is the terminals being exposed metal, other than that I think they're very robust bits of kit and I like the overall style. Plus of course they just work which is as it should be.

D.

 

[Techno]

Yes the bare busbars is a very good observation and perhaps it might be worth a mention to CTEK ?
I'm not a big fan of Sterling BTW I've had failures and their quasi sine inverters are supplied with cable far too small.
Looking at the spec sheet for their later pure sine inverters and cable size recommendations confirms that if you compare

 

[GAVLAD]

CTEK seem to use the same basic mould for all their top end units
I'm quite happy with the 25amp service charger and power supply and easily switch it between my two 500ah battery banks for recon charging
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Want one!

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