hooking up lipo's

[donzi22]

I am new to boats using lipo's with y harness connection and today I was progrmming my BJ using the card and I noticed that after I plugged in the first battery and then the other I had some small sparking coming from the second battery when the connector touched. My esc switch was off and I was following the instructions of the esc programming card. Can someone tell me if this is common?

[egneg]

Yes - but it can be taken care of by having a resister in parallel with one of the leads and hooking that up first. I can't remember who posted it but recently there was a thread that contained all the info for sizing the resister. I will see if I can find it.

Edit: Here is a link to the thread, scroll down until you see the post by Peter Zicha.

http://forums.offshoreelectrics.com/...light=resister

[Duclover]

Thanks for asking this question as I've had my BJ for 3 weeks and just got my lipos in this morning. Charged them first thing, then programmed the esc with the proboat module but couldn't get the prop to move, however, the rudder servo worked just fine. I had noted the arcing upon connecting the 2nd Lipo and wondered if I may not have shorted something. After playing with the module for 30 mins I ended up getting the whole package to function, well I might add. If the arcing doesn't harm anything then great but if there is a necessity to correct this issue I anxiously await the thread Egneg refers to. Hope to have many sessions to share and welcome Donzi!

[donzi22]

Egneg- I will take a look at the information. I have used Lipos in my planes for years but a single pack setup so this was a little new for me. Duclover- Thanks for the welcome. I have been reading the forums on this website for a few months and found that many people have a wealth of knowledge.
Thank you!!!

[donzi22]

As I reviewed the information it mentioned to use 20 to 50 ohm resistor depending on voltage. I am not much of electronics guy so if I am running 2- 3S lipo's could I use a 50 ohm resistor or will I loose performance? I would like to hedge on the high side so I do not limit myself for higher voltage if I so desire.