# B2B Battery Charging Disaster!



## terry111 (Apr 5, 2014)

We have a brand new Globecar Campscout with Electrobloc EBL99 and 2 leisure batteries.

As we rarely have hook-up and I wanted to be able to charge the leisure batteries more quickly than the EBL99 would allow, I was recomended to get a Sterling 100A battery to battery charger and an auto electrician fitted this for me.

On our first trip, the leisure batteries had got low overnight and after a few miles of driving there was a strong burning smell from under the passenger seat (where both the B2B and EBL99 are fitted). The overheat light on the B2B was illuminated but a charge was supplied to the leisure batteries and there was sufficient power for the evening and the system seemed to be charging (whether this charge was from the B2B or the EBL99, I do not know).

The auto electrician came to check the B2B and ran down the leisure batteries and then started the engine to see what the B2B was supplying. It didn't seem to be charging the leisure batteries but he said the EBL99 would still put a charge into them so we could still use the 12v system. 

Having left the vehicle on EHU for about 15 hours, there was some charge in the batteries (according to the voltmeter) and I hoped this would pick up as we drove off last night. However, after a couple of hours I checked it to find the voltage in the leisure batteries was still very low and the 12v supply would only work with the engine running (or, now I find, when on EHU). So, we returned home!

I have a few theories as to what has gone wrong here but my only electrical knowledge came from my A level physics course 40 years ago. Rather than me guess, if anyone has any knowledge of this I would be pleased to hear from them.


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## Steve121 (Apr 5, 2014)

Assuming you got a qualified auto electrician to fit the Sterling B2B, it's his responsibility to get it working properly at his expense.


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## terry111 (Apr 5, 2014)

Agreed, and I did get a qualified auto electrician. But I would still prefer to understand the issues for myself.


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## hextal (Apr 5, 2014)

Are you saying that the B2B and the EBL were both potentially supplying the LBs from the VB/alternator at the same time?  

Is the overheat light related to the unit or battery temperature?
Are the batteries holding any charge?  ie:- if you charge via a different unit from the mains, will the batteries hold it?
Are the batteries sealed or 'wet' units, can you check the fluid levels to make sure they haven't boiled and don't need topping up?  Any residue around the batteries?
Fuse on the unit ok?
What voltage are you getting on the battery?


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## maingate (Apr 5, 2014)

The EBL99 is designed to take a maximum charge of 18 amps (and a 2 amp float charge to the van battery on hookup). Your electrician should have checked this out before fitting anything extra.

It sounds like an expensive cook up. If your system is damaged, contact A & N Caravan Services. They will sort out the EBL at a reasonable cost.


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## terry111 (Apr 5, 2014)

hextal said:


> Are you saying that the B2B and the EBL were both potentially supplying the LBs from the VB/alternator at the same time?
> 
> Is the overheat light related to the unit or battery temperature?
> Are the batteries holding any charge?  ie:- if you charge via a different unit from the mains, will the batteries hold it?
> ...



Thanks for your response
I believe that both the B2B and EBL were potentially charging the LB's at the same time
The overheat light was related to the unit but this is no longer lit and the unit does not get warm
I haven't disconnected the batteries but I think they are holding charge
The batteries are Banner AGM
Fuses are fine
According to the vehicle voltmeter, the batteries at at 12.2v, even when on EHU
Thanks


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## Tony Lee (Apr 5, 2014)

One factor that needs to be looked at before buying B2B units is what is the rating of the alternator - or rather what is the long-term rating of the alternator. Hooking a 100Amp B2B charger up to an alternator with a short-term rating of 60 amps and a longer-term rating of more like 40 amps might be a bit optimistic.

Then there is the wisdom of trying to put 50 amps into a 100Ah battery. Sure, an AGM might be able to take it provided there is battery temperature monitoring fitted, but charging current that high might not contribute much to battery longevity.

The third factor is that the average auto electrician hasn't a clue when it comes to RV electrics.

BTW, it is rare that charging from multiple sources causes any problems. Quite common to have solar, engine alternator and mains charger all trying to do their bit. Normally one source will take the lead and the others will chip in when they can.



> According to the vehicle voltmeter, the batteries at at 12.2v, even when on EHU


which means that the batteries are only half full and the mains charger isn't working at all. Same with the B2B. If it isn't getting warm at all, it isn't putting anything in to the batteries.

For fault finding you need a cheap digital multimeter for measuring voltages. Even better is also having a DC current clamp (tong) tester, but they are a bit more expensive..


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## terry111 (Apr 5, 2014)

Thanks for the replies.

I think there are now faults with both the B2B and the EBL99

The EBL99 was fine until the B2B was fitted, thus my suspicion is that the B2B has somehow caused the problem with the EBL99.

The auto electrician (who works mainly on RV's) is likely to say the problems are unrelated and that he will fix the B2B but that the EBL99 is my problem.

Basically, I need some ammo!!


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## Siimplyloco (Apr 5, 2014)

terry111 said:


> Thanks for the replies.
> 
> I think there are now faults with both the B2B and the EBL99
> 
> ...



I know it doesn't help you fix this, but why would you want a leisure battery charge rate of more than 18 amps? EBL's and their ilk have been doing a great job for yonks now, and the vehicle alternator will charge both batteries when on the move. Strikes me that the marketing boys have have done yet another great job!
John


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## terry111 (Apr 5, 2014)

siimplyloco said:


> I know it doesn't help you fix this, but why would you want a leisure battery charge rate of more than 18 amps? EBL's and their ilk have been doing a great job for yonks now, and the vehicle alternator will charge both batteries when on the move. Strikes me that the marketing boys have have done yet another great job!
> John



Simply because I wildcamp, my toys (and my wife's hairdryer) draw a lot of power and I don't want to drive far each day. I can't blame the "marketing boys", I considered solar and given our weather a B2B charger seemed a better option. I've used a Sterling inverter for years and have always been impressed with them.


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## korky (Apr 5, 2014)

Hi there,

Have a look at A and N Caravan Services : Caravan Servicing, repairs, pre purchase inspection, Damp Checks-North Wales.. These guys repair Electrobloks amongst other things.

If you look at their topics under Electrobloks and under Battery Technology you will see they don't recommend the use of a B2B with an Electroblok or a Banner AGM Battery.

I was about to do the same as you until I read their comments.

In fact I think we've met, I'm the chap in the next village with the Globescout.

Very sorry to hear of your problems. 

John.


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## terry111 (Apr 5, 2014)

korky said:


> Hi there,
> 
> Have a look at A and N Caravan Services : Caravan Servicing, repairs, pre purchase inspection, Damp Checks-North Wales.. These guys repair Electrobloks amongst other things.
> 
> ...



Indeed we have met! Thanks for your comments, I'm sure it will be fixed soon, with or without the B2B!!


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## Siimplyloco (Apr 5, 2014)

korky said:


> SNIP
> 
> If you look at their topics under Electrobloks and under Battery Technology you will see they don't recommend the use of a B2B with an Electroblok or a Banner AGM Battery.
> 
> ...



Ahem! Having read it carefully I hereby rest my case......
John


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## terry111 (Apr 5, 2014)

siimplyloco said:


> Ahem! Having read it carefully I hereby rest my case......
> John


Indeed, had I seen this sooner perhaps I wouldn't have gone for the B2B. Hindsight is a wonderful thing but sadly I don't possess it.


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## sparrks (Apr 5, 2014)

The B2B can be used with AGM and various other types of battery - you just need to make sure the dip switch is set for the correct battery type. I've used B2B's for the last 7 years with no problems.


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## WildThingsKev (Apr 5, 2014)

I recently fitted a Votronic b2b charger, the manual included a wiring diagram for fitting in conjunction with an EBL.

You can download it here   

VOTRONIC - VCC 1212-45 (Marine)

It is in German but it is only the diagram on page 12 that you want, I think it would apply equally well to a Sterling b2b.

Kev


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## terry111 (Apr 6, 2014)

Thanks for your comments sparrks and kevina. The Sterling B2B does indeed have an AGM setting so, assuming Sterling know what they are talking about (and I think they do), the Banner AGM batteries shouldn't be a problem.

As for  the wiring diagram, I'll get this checked out (I don't speak German). However, I have spoken to a friend who is an electronics engineer, he looked at the wiring diagram for the EBL99 and pointed out which internal fuse has probably failed, with luck this is all that is wrong. He also said (translated into language I understand) that the output from the B2B has backed up into the EBL99 thus causing the problem. A diode should have been put into the cable between the EBL99 and LB, this may be what your German translation is saying.

Thanks again, I'm now understanding what's happened, what I've got to do to fix it and how to stop it happening again!


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## terry111 (Apr 9, 2014)

terry111 said:


> We have a brand new Globecar Campscout with Electrobloc EBL99 and 2 leisure batteries.
> 
> As we rarely have hook-up and I wanted to be able to charge the leisure batteries more quickly than the EBL99 would allow, I was recomended to get a Sterling 100A battery to battery charger and an auto electrician fitted this for me.
> 
> ...



Update for anyone who's interested:

"Disaster" is turns out was a major overstatement, thankfully it was just a blown fuse. 

The Sterling B2B has a setting for AGM batteries, so they shouldn't be a problem. My auto electrician is going to speak to Sterling to find the best way of isolating the B2B from the EBL99, this should be possible. Anyway, no harm harm done so that's the main thing!

Thanks for the helpful comments I received and we'll certainly check out the possible solution from Voltronic.


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## sparrks (Apr 9, 2014)

siimplyloco said:


> Ahem! Having read it carefully I hereby rest my case......
> John



I trust Sterling's comments more so than 'a and n caravan services'

A & N/Banner 

"This is recognised on the Banner Batteries web page which says :

WHEN RETROFITTING THE RUNNING BULL AGM PLEASE NOTE:
• _Do not exceed the maximum charging voltage of 14.8V_! Therefore, always examine the layout of the vehicle generator(Alternator).
• Only use voltage-regulated chargers with an IU-characteristic and the AGM/GEL charging programme.
• Do not open the screws of the Running Bull, as this results in an imbalance in the hydrogen-oxygen ratio and a loss of performance.
• Only allow a specialist company to retrofit a Running Bull"

Sterling's instructions

1) GEL US Spec Boost 14.0v, Time 1 - 10 hours, Float 13.7v
American gel manufactures want a different charging regime than the European ones. If in doubt ask the
battery supplier.

2) AGM U.S. spec. Boost 14.35V, Time 1 - 8 hrs, Float 13.35V
This is the setting which most American AGM battery manufacturers would like. Ask your battery supplier
for the correct setting as this is a new battery type which is becoming more and more popular.

3)Sealed Lead-Acid Boost 14.4V, Time1-12hrs, Float 13.6V
Sealed lead-acid batteries are simply lead-acid batteries which have no access to top up the water level.

4)European Gel / Exide spec. Boost 14.4V, Time12-24hrs, Float 13.8V
This program is, as per the recommendation of Exide, set at a voltage of 14.4 volts for about 12-24 hrs. The
unit then drops to float voltage to maintain the batteries.

5)European AGM spec. Boost 14.6V, Time 1 - 8 hrs, Float 13.7V
This is what the European AGM suppliers such as Optima want for their batteries. Again we would strongly
recommend you contact your battery supplier to confirm which charging option they require for their
batteries. This higher voltage appears to be for AGM batteries with a higher calcium content on the plates.

6) Open Lead-acid. Boost 14.8v, Time 1 - 8 hrs, Float 13.3V
The maximum boost voltage for this type of battery is 14.8v.

Note that the maximum charge voltage recommended by Banner for AGM batteries is 14.8v, the same voltage 
that Sterling uses to fast charge Open Lead-acid batteries. With Sterling's recommendation of 14.6v/14.35v
depending on AGM type.

The charge voltage recommendation from Banner and A&N seems contradictory.


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## sparrks (Apr 9, 2014)

terry111 said:


> Update for anyone who's interested:
> 
> "Disaster" is turns out was a major overstatement, thankfully it was just a blown fuse.
> 
> ...



Pleased to hear it was something simple and cheap


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## Teutone (Apr 9, 2014)

terry111 said:


> Thanks for your comments sparrks and kevina. The Sterling B2B does indeed have an AGM setting so, assuming Sterling know what they are talking about (and I think they do), the Banner AGM batteries shouldn't be a problem.
> 
> As for  the wiring diagram, I'll get this checked out (I don't speak German). However, I have spoken to a friend who is an electronics engineer, he looked at the wiring diagram for the EBL99 and pointed out which internal fuse has probably failed, with luck this is all that is wrong. He also said (translated into language I understand) that the output from the B2B has backed up into the EBL99 thus causing the problem. A diode should have been put into the cable between the EBL99 and LB, this may be what your German translation is saying.
> 
> Thanks again, I'm now understanding what's happened, what I've got to do to fix it and how to stop it happening again!



Beware, there is NO mention of a diode in the german document. I am not sure if it's clever to use the manual of a DIFFERENT manufacturer to wire a sterling product.


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## jeffscarborough (Apr 9, 2014)

My German campervan also has a EBL99 fitted. I always wildcamp and my solution to low voltage on the leisure batteries was a 100 watt solar panel and a plug and play controller (made by the same company who make the electroblok).

I also have a Honda 1000 watt generator as back up (unused for 2 years).

The solar set up is great, when the van is stood for weeks the batteries are always full (incl the starting one).

When camping in it the batteries charge up at 14 volts during the day.


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