Precharge Path using Deans connectors.

[Huthy]

Hey guys,

I put this in the Lipo Battery forum, but it has been pretty quiet over there, so I thought I would post a link to it here for the Razor or Ion people, since it is for my Razor setup anyway....

http://www.helifreak.com/viewtopic.php?t=31171

I think I am sorted, thanks to a mate locally talking me through it, but comments would be appreciated.

Thanks in advance,

Chris

[TomC]

Chris,

All this is a lot easier with bullet connectors I assure you, unless you are using a single 10s pack. I don't think that many long time Ion-x users would disagree with this.

If you had spent any time looking at mine or Luke Dodd's Ion setups over the last year, you would have seen how much easier it is to hook them up with bullet conectors.

Cheers,

Tom C

[Huthy]

Thanks Tom, but since I will be using Deans, I would still love to hear feedback from those that have done it.

[TomC]

I'm sure you will be fine with Deans connectors Chris. Luke and I (and I believe Will) just found the bullets easier.

Also, think about using a spark arrestor to avoid the big 10s spark you will get when you hook things up. Do a search or two and I'm sure you'll find out from other guys how to do this. Mine works great. No sparks, and no pitted connectors.

Cheers,

Tom C

[Huthy]

Also, think about using a spark arrestor to avoid the big 10s spark you will get when you hook things up. Do a search or two and I'm sure you'll find out from other guys how to do this. Mine works great. No sparks, and no pitted connectors.Tom C

Tom,

Did you actually look at the linked thread, or get hung up on the fact I was using deans? That is EXACTLY what I wish to do, and in that thread I have put a diagram of how I was intending to do it given that Deans are a 2 pole connector.

I found the description on RR... but would prefer a confirmation from the H-Freaks...

Comments appreciated.

Regards,

Chris

[TomC]

Chris, I looked at it mate but I could not follow what/where/how you were going to install your resistor and could not figure out what/why/how jst plugs were used.

Also, I did not really understand what you meant by 'pre-charge' I now see that this is your term for a spark arrestor, which does pre-charge the esc capacitors prior to final hookup, therby avoiding the big spark.

Sorry about this, but I think I get your drift now. I must be getting a little slow in my old age (another birthday tomorrow, yikes!).

Since you are going with Deans, and I assure you I do not have any problem with you using these connectors they are a very good choise, I would suggest you look at doing the following;

Refering to your Diagram 1 I would split the common black wire, the one that goes between your battery packs (+/-). Install a set of 4mm bullets (no this is not a trick to get you to use them!) on each end. Install a 80 ohm 1 watt resistor to one end and run a small length of small gauge (say 16-18) from the resistor to the other connector. Enough so that you can separate the plugs but still have this resistor and pilot wire connecting across.

So your common black wire (I think some guys have referred to this as a Jumper wire) will look something like this;

Bat 1 neg ----|----F-plug || M-plug-----|-----Bat 2 pos
pilot wire with resistor |--80ohm 1w--|

Pretty crappy schematic, but I think you can see what I mean. Heat-shrink the resistor over one end of the common lead.

Your 'pre-charge' proceedure will be to unplug the common wire bullets with just the pilot wire and resisistor are making a low current connection. Connect everything else. Wait a few seconds while the esc arms itself and them join the bullets together and go fly. The main current will then bypass the resistor/pilot wire so you do not have to worry about having to have additional connectors to disconnect it. If you try to start the motor without reconnecting the bullets, the resistor will blow like a fuse.

I'm sure that there are other ways to do this, but that's how I'd do it with your wiring setup. Hope this helps.

Edit; Bring it out to our field next time you are down this way and I'll bring my portable soldering station, plugs, and heatshrink and help wire it up for you.

Cheers,

Tom C

[Huthy]

Tom,

The diagram in my other thread was as a result of this:

http://www.runryder.com/helicopter/t184041p1

Specifically:

what you have to do is make up a duplicate lead to the one you are using on both the ESC and the battery only this one doesn't have to be heavy duty as it won't be doing any hard work. So you end up with two pairs of leads coming out of the battery and two pairs of leads coming from the ESC. If you're using more than one pack then put the resistors on the duplicate leads of the ESC and then all you need for the subsequent packs is the connectors / wires.

You then plug in the 'resisted lead' first and a couple of seconds later plug in the main lead - unplugging the resisted lead first after your flight before disconnecting the main lead.

Dunno if that helps any, in conjunction with the diagram.

That said, thanks for your input.

Regards,

Chris

[TomC]

Chris,

I have seen this setup like this before. In this case it was done for a 1 piece 10s pack and no doubt it will work. In your case you are using 2x5s1p packs and because of this you already have a common lead that goes between your 2 packs.

So rather than having to take another lead and connector to your battery packs, you can just do this using the common lead itself, as I've tried to describe. I think this should work great for your deans wiring setup.

The reason I went to an 80 ohm 1w resistor, instead of the 100 ohm 1w one (in the runryder thread) was I found that the 100 ohm resistor did not always startup the esc. It was no big deal since the main thing was after pre-charging up the esc capacitors for ~5-10 sec, I then joined the main plugs together it started up fine (and no sparks of course).

Hope this helps Mate.

Cheers, and no sparks,

Tom C

[WillJames]

I use Deans, and just replace them once they get burned to the point of me not trusting them. I have also changed ESC's enough to where they don't get that bad, although now that I have settled on using the CC ESC's for a while, I can see they will need changing before long.

I don't mind the spark, it is actually a good thing sometimes. HC had a bad Deans connector and the way he noticed it was when he plugged them together you could hear the spark, but as you seated them, the continuity was proken, then as you tried to unplug the spark happened again. Dead giveaway a bad connector.

[TomC]

That's great Will,

If you like sparks (and of course understand why they are happening), stay with what you have. If you want to avoid them, try making a simple spark arrestor. It's you're choice Mate.

Cheers,

Tom C

[gordohigh]

What about the question, (in the other thread), about the eagle tree data recorder? Will the small amount of juice that bypasses the FDR be noticable. It seems to me it would, therefore causing readings that are useless, or inaccurate.

Would like to know if anyone using the spark arrester is using a FDR.

[TomC]

Gordo,

Since electricity follows the path of least resistance. there is virtually no current flowing through the small gauge pilot wire w/resistor. I initially had another set of small 2mm bullets to disconnect the pilot wire, once the main leads were connected. Later, I measured 0 amps going through this pilot wire after hookup (with a clamp meter) and just left them connected after that.

Your FDR (I just use an onboard Wattsup meter) should not be effected.

I really do not think that +10s sparks are a good thing. I suspect, but do not really know, that these caused, or contributed to, my Ubec failure.

Cheers,

Tom C

[gordohigh]

Thanks, thats good to know as I don't think the sparks are a good thing either. I have been able to minimise them though, by starting one end in, and quickly sliding the other end in. If you line it up right, you wont see much of a spark, but as we all know, sometimes it isn't lined up perfectly and takes a second try..thnks

[Motions]

If your concerned about your data measurement with the spark arrestor connected, you could just disconnect it after you connect the main battery. The spark arrestor has no use after connecting the battery anyway.

[TomC]

Scott,

Like I said earlier, you can install another set of 2mm bullets on the pilot wire and disconnect these after startup. I did this initially, but found later that it was not necessary to disconnect them since after you hook up your main leads, the pilot wire/resistor is bypassed anyway.

Cheers,

Tom C

[Lusk]

I have been getting pitted deans and bad connections already and l've only flown my Razor a few times. I just installed a spark arrestor like tom described between - to + common lead between batteries with bullet connectors and it works great, i don't see how this way would affect any data measurement.

[TomC]

Glad you like it Lusk. Once you have used a spark arrestor you wonder why anyone would live with sparks. For less than $2 worth of parts, it's got to be the best value mod you can do for any +6s HV setup imop.

Cheers,

Tom C