Battery to Battery chargers. (Ctek or Stirling)

[tonyishuk]

 

Has anyone fitted these (Ctek or Stirling) ?

 

Do they do what is said on the box ?

 

What happens to the leisure batter(y/ies) if the starter battery is mains charged when on standby ?

 

Rgds

[Brambles]

I would think nothng, because the engine battery will be a higher voltage than it requires to be charged from the leisure battery. Assuming you use the battery to battery charger to support the engine battery.

I have read Sterling chargers can be affected by additional equipment being fitted like battery savers etc and they get a bit confused. Think it was Dave Newall who mentioned it.

( thats right, drop Dave in it Brambles - Editor!)

 

Anyway, I am kind of not too keen on using battery to battery chargers as its fair enough keeping the engine battery topped up but only of you have the capacity in the leisure so not to flatten it as well. Usually most people use them in conjuction with charging the leisure by mains or solar.

Jon.

[Peter Highe]

Hi

 

I think the Sterling battery to battery charger is used to quickly (much more quickly than normal) re-charge your leisure batteries when you are driving so that you recover more quickly if wild camping or using Aires off-grid. On the other side, a battery master will keep your vehicle battery topped up from the leisure battery. Neither will be affected by mains charging but the original monitoring system may well be confused. I get 'funny' readings from the Hymer control panel on charging currents because the Sterling effectively over-rides the Hymer's Electroblock.

 

Peter

[Brambles]

OK, I am getting a tad confused but cottoned on now. You are right I was thinking Battery Master.

[LMC Camper]

Not quite the same but - I've installed a Batter Master which keeps an eye on the charge of both batteries and always makes sure that the starter battery is topped up from the leisure battery.

It has certainly cured my starting problems and appears to have few other problems.

You can buy them here: http://www.campervanstuff.com/shop_stuff/index.php?mod=product&id_prd=976

 

Hope this helps

[tonyishuk]

The B2B charger is for increasing the charge to the leisure batteries as you drive.

 

The idea seems to be that it will (electonicaly) increase the charge to the leisure batteries to a higher voltage than the starter battery. Bearing in mind the alternator is also running the fridge, maybe other equipment and the Leisure batteries could have a lot of ampHrs to make up if discharged.

 

As said above the Battery Master works the otherway round when the vehicle is parked up and makes sure the start battery does not get too discharged.

 

Rgds

 

 

[davenewellhome]

B2B chargers work by loading the starter battery to force the alternator to produce more current than it would otherwise do. Both CTEK and Sterling do similar things, the main difference is the Sterling will throw up to 50 amps at the leisure battery(ies) while the CTEK does up to 20 amps. Both systems offer four stage charging of the leisure batteries. I have fitted both systems and am presently using a Sterling unit on my own motorhome. If you charge the engine battery from the mains with an external charger the Sterling will kick in and pass some current to the leisure battery(ies) so you can actually charge both battery systems from one charger, assuming it has a high enough output capacity, I use a CTEK XS2500 in the workshop and generally connect it to the engine battery for 24 hours before we plan to go away in the camper.

 

D.

[harry the horse]

Hi Tonyishuk.

 

I went to the NEC show in Febury armed with info of suppliers to fit a solar panel to our van. But a leading alarm firm surggested with our style of camping he surggested a Sterling B2B charger, on RoadPro's stand Andy told me the same thing as did Dave Newell who was also on the stand so I did the deal & Dave fitted it for me in about 3hrs & at a great price!

 

So whats it like? We have been on CL's & at the Peterborogh MH show with no EHU with lighting, heating & sat tv running battery down to 11.9v. in the morning. With the engine at tickover for half an hour the reading after a settle down period was 14.1 just that for yourshelf. I asked my imediate neighbours at the show about the engine noise & they honestly said they could not hear it but could hear the generator about three vans away. I am still monitoring it, but I think I made the right choice & I had some great advice. Good luck.

 

HTH

[tonyishuk]

Many thanks for your replies.

 

The only concern I have is charging rates of 20 plus amps, that seem to come from some of these chargers (also similar) mains chargers.

 

I may be old school, but I have always understood, that about 5 amps over a long period, is a much kinder way to treat a battery. Granted the battery may not get to full charge for some time.

 

Rgds

[spartan3956]

I would agree lower amps is much kinder to the batteries i have had them boil in the past.

[smifee]

I don't want a love in with my batteries. I just want them to be fully charged.

 

I think if you ensure that they are topped up regularly then it matters not if they 'boil'.

 

My 4 Elecsol 125Ah batteries have been topped up with 7.5 litres of top up water in 5 years and are still going strong.

 

They are mostly charged by a Sterling B2B charger & 2 X 75w solar panels. I have a mains multi stage charger but it doesn't get used much.

 

Had 7 weeks away recently and didn't use any campsites or hookup. Batteries performed well. Solar panels didn't get much sun and spent several days covered in snow but the Sterling coped well. But then I did do 5200miles :-D

[Tomo3090]

If your van has a Sargeant Electrical Control Box then it won't like a Sterling set up. (The guy from Sargeant told me that at the recent Autotrail Rally.)

 

I've got a Battery Master and it works great. The two solar panels keep the leisure batteries topped up when we are at hom and the van's parked up and the battery master takes care of the vehicle battery. There's never been a problem with the vehicle alarm, radio running down the battery since it was fitted.

[tonyishuk]

Thanks for your replies.

 

By coincidence I found Clive Mott-G's write up on chargers in April's MMM, (if hes montering, - Many thanks).

 

Rgds

[tonyishuk]

davenewell@home - 2010-05-12 7:22 PM

 

B2B chargers work by loading the starter battery to force the alternator to produce more current than it would otherwise do. Both CTEK and Sterling do similar things, the main difference is the Sterling will throw up to 50 amps at the leisure battery(ies) while the CTEK does up to 20 amps. Both systems offer four stage charging of the leisure batteries. I have fitted both systems and am presently using a Sterling unit on my own motorhome.

 

D.

 

I was pondering (as one does (lol) . I understand that the B2B charger will control the charge into the leisure battery bank and vary voltage and current to suit the situation.

 

What happens to the starter battery whilst this is going on ? Does it get a wack of volts and current similar to the Leisure battery charge ?

 

If the B2B takes its input from the battery positive terminal, the starter battery positive post must be receiving max amps and voltage for the B2b to act upon and then pass onto the leisure battery.

 

Is this detrimental to the starter battery ?

 

Apologies if the above seems muddled, but I think you can guess what I mean.

 

Rgds

[Brambles]

The way rwcall it from ehen I read the details of B2B is...

The B2B will only only start loading the Altenator, and hence engine battery +ve terminal, when the volts on the engine battery is healthy and is in good state of charge, I think it around 13.5v but would have to check for exact value. So it does have an effect on the starter battery charging fully but will not stop it getting enough charge to be left in a safe condition. Putting it another way it will only charge the leisure batteries once the starter battery has had a fair share of charge and then because so much avaliable curremt is being used to charge the leisure batteries the starter battery will recieive less than it would have done.If the engine is running fast then it probably does not make a lot of difference to the starter battery as there will be enough power to charge everything.

[tonyishuk]

Thanks, your explanation makes sense.

 

It seems the way to, I will have to start saving some pennies, the B2Bs are not cheap !

 

Rgds

[tonyishuk]

Still kicking this one around !

 

I read somewhere that some types of M/home battery management systems (Hymer / Rapido ?) do not get on too well with a B2B charger. It seems that if you are using the M/home on a EHU, the leisure battery is charged up then the battery system switches a charge to the vehicle battery which is picked up by the B2B unit and starts to cause a sort of oscillation in charging.

 

If a B2B is fitted (generally a good thing) it needs to be isolated either by a relay or mannual switch when on an EHU.

 

Any experiences / comments ?

 

Thanks

[Brian Kirby]

tonyishuk - 2010-06-11 5:31 PM Still kicking this one around ! I read somewhere that some types of M/home battery management systems (Hymer / Rapido ?) do not get on too well with a B2B charger. It seems that if you are using the M/home on a EHU, the leisure battery is charged up then the battery system switches a charge to the vehicle battery which is picked up by the B2B unit and starts to cause a sort of oscillation in charging. If a B2B is fitted (generally a good thing) it needs to be isolated either by a relay or manual switch when on an EHU. Any experiences / comments ? Thanks

It might be worth reading Sterling's piece on batteries on their website, because it seemed to me that they were very pro "flooded" batteries, on the basis you could "push" charge them (my term) because the only consequence for the battery was more rapid loss of electrolyte.  The implication seemed to be that provided you kept an eye on the electrolyte level, and kept the battery topped up, no harm would result.  All well and good, providing your battery is readily accessible.  I gained the impression (or maybe even read) that the B2B is, for this reason, not suitable for use with gel (or presumably AGM) batteries.  I also seem to remember reading a warning about its use in conjunction with certain types of chargers, with the implication Sterling chargers would be fine.  Ho hum!  I'm not knocking their gear, which has an excellent reputation, but I wonder whether, at the price, when all factors are entered into the equation, it is a truly economical remedy, compared to increasing the battery capacity.  A larger battery bank would seem to me, pound for pound, a better path to take, because it will bring benefits beyond a mere increase in capacity - always assuming you have the necessary accessible space and payload capacity.

[Brian Kirby]

Sorry, that last sentence doesn't make proper sense.  What a B2B achieves, is a few more Ah into the existing batteries, which gives a small, though useful, increase in stored capacity, but also a quicker rate of charge.  What I meant was that the additional battery, naturally, adds a much larger chunk of stored capacity than those relatively few extra Ah can achieve in more fully charging the batteries, by doubling, or better, your existing capacity.  The main advantage of the B2B seems to be the speed at which the batteries are charged, rather than the additional depth of charge achieved.  If you need the speed fine, but if you want the extra capacity, more battery seems a more cost-effective solution.

[weldted]

I have a 50am Stirling B 2 B charger fitted to look after three 100 amp leisure batteries, I have had it for over a year and have onlt topped up the batteries twice. There are dip switches on the right hand side of the unit so you can select which type of batteries you want to charge. I have wet lead acid. I have a Bessacar and can when on mains select which battery either engine or leisure, if I select Engine when the voltage is up the B2B starts to charge the Leisure batteries via the B2B at a higher rate than if the mains charger was set to the leisure ones. I have had several different Motor homes over the years and can honestly say that since fitting the B2B I have not had mains hook up unless it was included in the pitch fee, and regualy wild camp for up to ten weeks at a tme, I have two Spr 90 watt solar panels and a blue point tracking regulator and between the two manage well. Whilst it is not cheap I have found that during the winter months the way it charges the batteries is noticable and would say it is the best bit of kit I have on the van. No I do not sell them!!

[weldted]

Sorry one further point if you just fit more batteries you have more weight and will need longer to charge them and if you have a lot of batteries and a standard charger if you are not on hook up regualy you run the risk of carrying around a lot of half charged batteries that will give you no more use that a couple of fully charged ones.

[Brian Kirby]

weldted - 2010-06-12 5:21 PM ........... I have a Bessacar and can when on mains select which battery either engine or leisure, if I select Engine when the voltage is up the B2B starts to charge the Leisure batteries via the B2B at a higher rate than if the mains charger was set to the leisure ones. .............

But, just in case this may not be quite obvious to everyone, I don't think this will be equally true for those charger systems that are not switchable between leisure and starter batteries, but simultaneously put out a 2 Amp trickle charge to the starter battery while charging the leisure battery.  I think this may be where some of the incompatibility problems arise, because the B2B and the on board charger would both be trying to charge the leisure batteries, but at different rates, using different regimes.  

Anyway, you're cheating Ted, you're using solar panels instead of mains!  :-D