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Ron Rosenberg asked

Blue Smart IP67 12/17 not going to float

I connected a new IP67 12/17 charger to motorhome chassis batteries, 2 group 31, that were partially discharged at 12.4 volts. These batteries are one year old. Unit would go from bulk to absorb and move to 14.4 volts and 1.4 amps. Instead of going to float it would start all over again with a short bulk charge, same absorb charge, over and over again. I removed Victron and successfully charged with a CTEK charger.

I returned the unit to Amazon. I order the Victron for its 7 day refresh and then turn off. I felt this was perfect for a motorhome not in use that does have a small parasitic drain on the chassis batteries.

Should I order another one? How hot does the unit get at 12v/17amp?

charger
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Alexandra avatar image Alexandra ♦ commented ·
@Ron Rosenberg

Battery type?

And did you program the charger for the batteries?

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Ron Rosenberg avatar image Ron Rosenberg Alexandra ♦ commented ·
Yes. Batteries are group 31 wet cell lead acid. I have not had a charger that would go from absorption to bulk instead of going to float. It just kept doing this till I gave up on it. I even tried six amp with the same result.
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kevgermany avatar image kevgermany ♦♦ Ron Rosenberg commented ·
Usually going from absorption to bulk is because a load kicked in. Fridge maybe?
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Ron Rosenberg answered ·

Fridge is off. Small parasitic draw of less than 2 amps @12v. Probably some Freightliner/Cummins computers. I did not turn the chassis battery disconnect off. That would not be the way I would be using the product had it worked. Probably just a defective unit.

When the mains are connected the Multiplus two keeps the chassis batteries from going dead. When dry camping for extended periods this does not function. My plan was to power this charger from the inverter output when not connected to mains or not driving the motorhome. "Turns on every seven days to check battery and top up if needed". That was my plan anyway. I have one empty 120v breaker that I was going to use for the permanent install of this charger.

If the starter battery was down, I can merge with the house bank for an emergency start of motorhome engine. But, allowing the starting battery to sit at lower levels of charge can lead to having to replace the battery sooner that it should be. I was trying to avoid this and allow the solar through the inverted to keep this battery topped up.

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