Battery to Battery Chargers - Thoughts Welcome (1 Viewer)

[Pausim]

The charging rate was a concern but no one has raised this as an issue and if B2Bs wrecked batteries I think it would be something well known.

I have read that a charging rate of up to 30% of the ah rating is ok for lead acid batteries. So a 50 amp charge rate for a 180 ah battery bank should be fine.

 

[Chockswahay]

Dunno if this helps but I took a few snapshots of my charge rate today from the alternator

The journey was broken up in to 3 as we stopped in Avignon for a couple of hours then at Fontaine de Vaucluse for a couple more before setting off to Gordes.

Initial charge.....

This one is 30 mins later ....

Then at one hour.......

The charge rate continued at around 15 a/h + for the next hour then after 2 hours 30 mins (engine on time) the rate when we stopped was just below 10 a/h......

Lastly after about 45 mins on site the readings had settled as shown in the following image.....

In practice it would take a good while longer to reach 100% and I am not too bothered. I have found that the useful ‘indicated’ range is between 60% and 90%

These readings are on a new Fiat 130 manual. If someone with B2B could show some readings it might help to make a comparison?

Note: The battery shows as 180a/h capacity (actually 2 x 95) because I have re calibrated to allow for some inefficiency.

 

[hilldweller]

and there is no concern about the charging rate buggering engine batteries

Though engine batteries hardly ever deep discharge. 800A for 5 seconds and top it up.

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[DBK]

Dunno if this helps but I took a few snapshots of my charge rate today from the alternator

The journey was broken up in to 3 as we stopped in Avignon for a couple of hours then at Fontaine de Vaucluse for a couple more before setting off to Gordes.

Initial charge.....

View attachment 263576

This one is 30 mins later ....

View attachment 263577

Then at one hour.......

View attachment 263578

The charge rate continued at around 15 a/h + for the next hour then after 2 hours 30 mins (engine on time) the rate when we stopped was just below 10 a/h......

View attachment 263579

Lastly after about 45 mins on site the readings had settled as shown in the following image.....

View attachment 263580

In practice it would take a good while longer to reach 100% and I am not too bothered. I have found that the useful ‘indicated’ range is between 60% and 90%

These readings are on a new Fiat 130 manual. If someone with B2B could show some readings it might help to make a comparison?

Note: The battery shows as 180a/h capacity (actually 2 x 95) because I have re calibrated to allow for some inefficiency.

I suspect your alternator is on the electrical equivalent of steroids. I've never seen those sorts of currents. Hmm...

 

[rupert]

I got a sterling bb1250 direct from sterling earlier this year for £150 same charger is normally £375 not sure why the discount, seems like a nice solid piece of kit but pricey at £375. easy to fit and charges three 80ah batteries pretty quick. charges at around 14.5v the fastest charge is for open LA batteries.gels charge much slower and probably not much gain there.when battery is low the most I've measured is 40amps with clamp meter. I think one of these is the answer to your problem recommended

 

[Abacist]

I get the impression that Sterling has a full on corporate website as one would expect but then there is another one where it's like Sterling himself is flogging off stuff cheap with no or very restricted warranties, perhaps repaired returns, reconditioned items or whatever. I certainly got a cheap one to start with as its a lot of money for a charger until you realize it's sophistication, charging capacity etc.

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[rupert]

yeah my warranty was only one month but that didn't put me off as you still have sale of goods act to fall back on. I got two temperature probes included, one for alternator and one for battery bank. not had it long but working well so far

 

[rupert]

@DBK just looked on sterlings site the same b to b as I got is now on offer at £199.

https://sterling-power.com/collections/battery-to-battery-chargers

 

[Pausim]

I don’t have comprehensive readings like @Chockswahay has shown and requested. I think the notable difference between my Votronic B2B with his readings is that my voltage goes straight to the 14.6v it is set at and then appears to charge steadily at the 38a limit (set to match my Elektroblock specification) until the first phase has been completed i.e. battery full.

I can’t swear to the exact profile of charging because I have not needed to follow it that closely. The amps appear to drop off a cliff edge when the battery is full but this is possibly a feature of charging LiFePO4 and might be different with lead acid.

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[Armytwowheels]

When we sold the van I removed it and sold it to army two wheels you may want to ask the how they get on.

You sure did and we are very pleased with it. Our current van goes to it's new owners tomorrow, but the B2B is staying with us and is tucked up in it's box waiting to be reinstalled on our next van, a great addition to our power hungry way of motorhoming.

 

[Ivory55]

Doing things yourself comes in to the economic of having stuff for the van, if you’re a gaffa tape and hammer person who has to pay people it puts a different slant on things.

 

[Lenny HB]

I suspect your alternator is on the electrical equivalent of steroids. I've never seen those sorts of currents. Hmm...

Because he has a German van and you have a Brit van with undersized wiring.
I think I've mentioned it before.

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[AXO66]

Just found this web site.

Seems to cover all issues re batteries charging solar.
Have a look at secound battery issues re large currents through a syastem not really up to it( accirding to them)
Worth a browse just for their insights.

http://www.aandncaravanservices.co.uk/

 

[DBK]

Just found this web site.

Seems to cover all issues re batteries charging solar.
Have a look at secound battery issues re large currents through a syastem not really up to it( accirding to them)
Worth a browse just for their insights.

http://www.aandncaravanservices.co.uk/

Thanks, I've had a quick scan and while I can't argue with what they've written none of it seems to mention B2B chargers.
The reason B2B chargers seem to work well is they charge the batteries at a higher voltage than the alternator alone will do even if the charging wiring is generously proportioned. For example, the vehicle alternator won't continuously charge for an hour or so at say 14.4 volts but a B2B can.

 

[AXO66]

I think they have a section on Battary to Battery in their home section.
Not what I was looking at I need a New battery .

Also as an aside, they point out solar panels always seem to start the new day on a full charging power ,possibly resulting in battery damage as the battery state suggests a maintenance charge is requred.

These electrics realy are more complicated than positive and negative

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[Lenny HB]

Also as an aside, they point out solar panels always seem to start the new day on a full charging power ,possibly resulting in battery damage as the battery state suggests a maintenance charge is requred.

Same thing happens with the mains charger each time you plug into the mains. With modern multi stage chargers (mains & solar) not really a problem as if the batteries are fully charged the charger will only stay in the bulk charge phase for a short while.

 

[JockandRita]

Here is another happy chappie with reference to the Sterling B2B.

After doing much research and speaking to Nick at Vanbitz several years ago, (Is that the same Nick as @nickvanbitz? Have you returned?) as well as Sterling themselves, I installed the B2B1250 model, using 30 x mm sq welding cable, connecting the starter battery to a then, Elecsol 220Ah, (now 2 x 6v traction batteries @ 225Ah).

Although I have had a very recent problem with overcharging (15v), by due process of elimination, I was able to exclude the B2B as a possible cause, to find that it was the voltage regulator in the back of the alternator. (Thanks to @Lenny HB, for confirming my suspicions. ).

Another plus for the B2B, is that the onboard Shaudt charger is only rated @16A, and can be put under strain with a battery bank above 180A, as advised by A and N Caravans, so the B2B does most of the bulk charging, just leaving the Schaudt until to top up and condition charge.

I definitely wouldn't want to be without our trusty B2B.

Cheers,

Jock.

 

[Lenny HB]

Another plus for the B2B, is that the onboard Shaudt charger is only rated @16A, and can be put under strain with a battery bank above 180A, as advised by A and N Caravans, so the B2B does most of the bulk charging, just leaving the Schaudt until to top up and condition charge.

Getting your wires crossed Jock the 16amp charge rate on the EBL is only on mains charging. For alternator charging Hymer fit decent size cables and the split charge relay is in the EBL but you will still see charging rates in excess of 30 amps if the batteries are flat with the standard set up.

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[JockandRita]

Getting your wires crossed Jock the 16amp charge rate on the EBL is only on mains charging.

No, not getting my wires crossed Lenny, however, I did inadvertently omit the word "mains", although I did state the "onboard Shaudt charger".

Cheers,

Jock.

 

[Miss Trinity]

As a newbie i am still surprised that no one has raised the issue of the DPF as its an on-going concern for many what with the tightened restrictions on emissions and the increasing complexity of the engine management sytems. Surely it aint advisable to leave diesel engines idling for even short periods as it will clog up the filter prematurely. Or am i missing something in the tread as have been plagued with DPF issues in the past... Meow for now =~,~=

 

[Ivory55]

If you’re worried about tick over jam something on the throttle

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[Pausim]

I think the general idea is for the B2B to do its work during normal driving.