# Battery to battery charges and Schaudt EBL 101 and DT 201B



## javea (Jun 8, 2007)

I have been looking into fitting a battery to battery charger to the Hymer. The two systems that I looked at were the Sterling and Ctek.

As I had almost immediate replies from Sterling regarding my enquiry, and had to email Ctek twice before I received a reply Sterling were favourite. However, when I phoned them for advice about wiring (Ihad heard that there might be a conflict with the Schaudt Electroblok) I was advised to disconnect the cable from the item, tape it up and take the cable from the charger direct to the batteries.

Didn't like the idea of this so I emailed Udo Lang at Schaudt and found him to be most helpful. He advised against using a battery to battery charger as the vehicle is fitted with a DT 201B control panel, he said:-

"in case you have a digital panel, (any DT) please be cafefully with charging voltages of about more than 14.6V. The panel will give an alarm
that there is an overloading in the system!!
If you have no DT the problem is not there and you can use the sterling charger."

He is of the opinion that a generator is a much more sensible way to proceed so as not to cause problems with the system and recommends the fitting of an OVP 01 to protect the system from voltage fluctuations in the generator and also the supply from hook ups in the south of Europe which he says can be problematical.

If you have any queries with Schaudt equipment he is very helpful and can be contacted on [email protected]


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## erneboy (Feb 8, 2007)

I have a Sterling B2B fitted. My Eb control panel is a DT 220 and the unit is an EBL220. My B2B is connected straight to the batteries, not through the Ebl as Udo told me that the ampage was too high for it. There is a problem in that the readings are wildly inaccurate when the B2B is working however the batteries recharge very quickly and then when I stop the engine all the readings are normal again. I have had it for two years without problems, Alan.


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## Jean-Luc (Jul 21, 2005)

erneboy said:


> I have a Sterling B2B fitted. My Eb control panel is a DT 220 and the unit is an EBL220. My B2B is connected straight to the batteries, not through the Ebl as Udo told me that the ampage was too high for it. There is a problem in that the readings are wildly inaccurate when the B2B is working however the batteries recharge very quickly and then when I stop the engine all the readings are normal again. I have had it for two years without problems, Alan.


Mine is also wired directly to the batteries but I have a relay in the feed from the batteries to the Original Equipment which drops out and isolates the OE from the high voltage from the B2B.
I was also concerned about feeding 14.8volts back into both the habitation and original chassis electrics. 
The circuit diagrams which come with the B2B unit all show circuits which do not come into contact with original vehicle circuitry ( in fact the circuits refer to boats and bow thrusters !).
Stirling never did assure me that 'showing' 14.8v to the OE would definitely not cause issues with the engine management systems or the CBE end of things.

I was unable to disconnect the split charge relay, as advised by Stirling, as it seems to be built in to the CBE kit somewhere and not 'disconnectable'.

All said though, the B2B really looks after the batteries very well


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## CliveMott (Mar 10, 2008)

Interesting to note that the Sargent EC325 system fitted to later up market campers has an intelligent charger that works in both mains and driving modes and provides similar voltages to a B2B. BUT the EC325 also has a twin power supply system built in such that when hooked up one power supply runs the habitation equipment at a "sensible" voltage while the other power supply charges the battery at higher voltages if deemed appropriate.

Sounds familiar?

C.


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## Jean-Luc (Jul 21, 2005)

CliveMott said:


> Interesting to note that the Sargent EC325 system fitted to later up market campers has an intelligent charger that works in both mains and driving modes and provides similar voltages to a B2B. BUT the EC325 also has a twin power supply system built in such that when hooked up one power supply runs the habitation equipment at a "sensible" voltage while the other power supply charges the battery at higher voltages if deemed appropriate.
> 
> Sounds familiar?
> 
> C.


Which is precisely why I fitted a relay to isolate the habitation and vehicle equipment from the output of the B2B when it is powered up (not being able to identity and disconnect the split charge relay would have meant that the B2B output would feed back into the vehicle systems).
In Rapido's, being a European manufactured product and not suffering from the NCC requirement that the habitation 12v systems be isolated when the engine is running, there is always power there from the engine side when the habitation batteries are isolated.


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