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Northeaster 11-16-2008 09:17 AM

New Battery charger (unplugged) causes spark on battery post!!
Hi Folks,

I bought an Iota 45a Intelligent (Q4) battery charger in the summer, but didn't have time to install it.
Now that the boat is in storage for the winter, I removed the 2 group 27 flooded house batteries (new this spring). Brought them to the house for warmer storage, and figured I would use the Iota to charge / maintain them throughout the winter, and install it in the boat in the spring. It comes with a 3 prong AC plug!

I had NOT yet plugged in the charger to the AC outlet, but when I tried to connect the leads to the 1st battery, I got a decent spark!!!
Double checked everything, tried again, same result!

Looked like the charger was shorting out the battery! Got out the multimeter, set for Ohms (2K). ** Electrical not my strongpoint, but do understand basic short, ground, etc**** Got reading of .54 on pos /neg leads from charger!!
Not sure what I was expecting for readings, but since the charger was not plugged into AC, I did not think a spark was normal. Should the charger leads show open / no resistance (1.0 reading) until it is plugged in and starts charging? Or is this normal??

I did NOT have the chargers ground lug connected to ground either, but don't think this woudl matter so far.


Idiens 11-16-2008 09:20 AM

I think the charger may have some big capacitors inside and that spark is caused by them charging up when you connect the battery. So it may not be an issue.

Northeaster 11-16-2008 09:39 AM

Idiens - Thanks for the reply. I am hoping that there is an explanation, similar to what you have said. I figured it was worth asking the experts here, rather than connect it and possibly do some damage.

Idiens 11-16-2008 10:51 AM

If the charger has a fault, you will have to send it back anyway. Try connecting it and plugging it in. Make sure you have the polarity right of course. If the battery is being short circuited, it will cook the charger. If not, it should behave normally and you can use that multi-meter in its volts mode to see what is happening at the battery terminals. Anything between 12 and 14.4 volts is "normal".

Northeaster 11-16-2008 10:55 AM

Would it hurt to plug the charger into the AC outlet, without connecting the battery, for a few minutes?

Would this "charge" the internal capacitors (if this is what is causing the spark / draw on the battery), or would it do nothing without the battery connetced?

Idiens 11-16-2008 11:46 AM

It should not hurt the charger to be plugged in but not connected. Just don't let the outlet leads touch! (Even then, it should be fused).

I don't know the charger, but I am never surprised to see a spark when connecting a battery.

I would however normally connect the battery prior to plugging in the charger.

P.S. What does the charger's handbook say.

thekeip 11-16-2008 12:11 PM

What IDIENS said.

The spark is a normal thing, and it will occur even when connecting the 2nd output to the 2nd battery.

Howard Keiper

Northeaster 11-16-2008 12:11 PM

Handbook just says to connect the battery leads, ground lug, and then plug into AC.

If a spark is common, it woudl be nice for them to mention it in the manual!!

I am not talking a huge spark, like what you get if you short out jumper cables, when boosting a car. However, it is definitley a noticible spark, and I don't want to do permanent damage to the battery, or charger, if I can help it.

If anyone else has noticed something similar, it would be nice to get additional confirmation!

Thankd agin for your input Idiens!!

Northeaster 11-16-2008 12:13 PM

Keip - Sorry, didn't see your post!! Thanks for the input!

Northeaster 11-16-2008 12:26 PM

Connected it up, and seems to work fine. Putting 14.57V accross the two batteries as I write this. Will keep an eye on it, to make sure it goes into float stage.

Thanks again!!

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