bpsshb avatar image
bpsshb asked

Simple Campervan with solar & Bluesmart mains charger

Hello folks, a couple of questions. I have a VW camper with a solar panel c/w Bluesmart 75/15 MPPT controller connected to a SuperB Lithium 90Ah battery with built in BMS. I need to add a mains (240V) charger & am looking at either the Bluesmart IP22 12/15 or the Bluesmart IP65 12/15. Reading through the instruction manual for the IP35 version, I see that a "Test" is carried out prior to charge commencing,:-

The TEST LED will flash as long as a charge pulse does

not increase battery voltage to more than 12,5V resp. 25V.

If the flashing persists during several minutes the battery is

probably damaged (internal short-circuit): disconnect the


A false rejection may occur if a load is simultaneously

draining a very weak or fully discharged battery during the

test phase: disconnect the load and repeat the test.


1) If during the test phase, the solar charger is charging the battery, would the IP65 12/15 charger see the increased battery voltage & assume a fault & fail the test?

2) Is the IP35 version designed to run in parallel with other charging sources? If not, would the IP22 version suffer the same problem?

3) The charger will be permanently hardwired to the to the battery. Depending on circumstances it's highly likely that the charger maybe powered up whilst loads are simultaneously connected, (fridge/lights/diesel heater etc.) these loads may be running during the "test" phase, would this be an issue for either charger in question?

4) If the "test" fails, does the charger lockout until the next power up cycle or does it retry after a period of time?

5) Is there a more suitable charger for the application, it must be Lithium capable & be suitable for permanent installation in a small space, preferably fan-less.

Thanks for any help.

battery chargingLithium Batterysolarcampervan
1 comment
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bpsshb avatar image bpsshb commented ·

Thanks for the answers gents, much appreciated. I was confused by the wording in the manual, which to me reads that if the voltage remains high during the test phase, then the test would fail. Anyway, problem solved & question answered, thanks again.

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2 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi @BPSSHB, the test fails when the voltage remains low. Not when it is high.

Yes, multiple chargers can be used together on the same battery bank. All models.

The charge current might not be shared equally between them, and there will be no “solar priority”; which now that I think of it could be partially solved by setting the mppt charging voltages a bit above the used values of the mains charger: once in absorption or float, they act as voltage sources. And then the drawn current will be supplied by the source thats configured with the highest voltage.

Yes it will lock out when the test fails, but I don’t see a reason why that would be happening to you.

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wildebus avatar image
wildebus answered ·

FWIW, the combination of an IP22 AC Charger and a SmartSolar MPPT is one I use pretty frequently in VW Conversions and works well.

As mvader has said, putting the charge voltage setting on the MPPT a little higher than on the AC Charger will effectively make the "free power" from the Solar the priority - this is how I have got my own combination of MPPT and Multiplus in my VW Camper setup.

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