Connecting the Cellpacks

cadric

cadric

Member
Joined
May 3, 2018
Messages
110
Hi,

I'm done with adding the busbars to my packs.
Now I'm at the stage of creating a connecting solution and would like some input:

I planned a harness with 14 x XT90 connectors, to connect each pack to.
But as I want to add additional packs later when I have enough cells again without the need of more Longmons,
I want to add some multiplier connectors, compareable to the ones shown in this picture only linear instead of circular:


image_wyerev.jpg


Additionally I want to integrate the Longmons into that multipliers:

image_pvkbib.jpg


The overall layout would then look like this:

image_gvgkds.jpg



So, what do you think about my solution?

regards

cadric
 
Works.
Beware of the size of pack per longmon. Recommended is to stay within resonable limits like below 400Ah
 
Also be aware that the XT90 can only do a max of 90A continuous, and that's if they are the legit connectors, and not knockoffs.
 
daromer said:
Works.
Beware of the size of pack per longmon. Recommended is to stay within resonable limits like below 400Ah
Click to expand...

Hi daromer,

400Ah per Longmon? OK, didn't know this. Thanks.

1st Level is 14S60P ~ 90Ah per cellpack.

regards

cadric

Korishan said:
Also be aware that the XT90 can only do a max of 90A continuous, and that's if they are the legit connectors, and not knockoffs.
Click to expand...
Hi Korishan,

you're right, I have to keep this in mind. It would mean two levels with 60P cellpack could already be to much.
But I plan to charge/discharge each pack only with max. 30Amps. Also even this would cut the levels of additional 14S Cellpacks to max. 3.
Would you recommend some other type? Anderson style like average Joes? I read they can handle 50A.
Or does anyone have another Idea for the connectors for this kind of harness layout?


regards

cadric
 
Ok,

then I have to rethink the solution for the harness connectors.
But the xt60 for each cellpack would fit the values of 30amps.
Maybe I also split them into positive and negativ ones.

Thanks all for your comments.
Time for bed now.

If anyone has additional infos, I would be lucky to read about.


regards

cadric
 
You can get XT150 or the larger connectors used for truck batteries (Name?)

Dont undersize connectors. :)
 
I really like the Anderson Powerpole connectors myself over the XT series. They have the little guys that go down to 15 amps if you're making something small but then for the larger packs I tend to use two of the PP75s for each pack positive and negative. This is just because my busbar creates a loop anyway and the PP75s tend to be much cheaper than the larger SB120s and up (at least the genuine ones, not knock offs). They also allow you to separate or connect any amount of single terminal to any other terminal using roll pins which is nice. And theyre hermaphroditic (which usually isn't my cup of tea in normal every day life but works great here). Finally, they're all crimpable too.

The XT series I'm okay with for smaller packs, like RC batteries, but I think if you use the PP75s or PP120s once or twice, you'll see how robust they are.


image_hjdfut.jpg


image_rarqyy.jpg



In fairness the larger XTs like the ones below also allow you to mate two terminals together or separate them. They're basically bullet connectors


image_gvctia.jpg
 
Gentlemen,

thanks you al for you input. I will keep it in mind for further development.
As I'm starting with 60P cellpack now and want the system to get going, I will start with using the xt60 now,
but will upgrade to bigger connectors when I have more cell packs to add to my system.

Thank you all again,

regards

cadric
 
Korishan said:
Also be aware that the XT90 can only do a max of 90A continuous, and that's if they are the legit connectors, and not knockoffs.
Click to expand...

I have always wondered how a (legit) XT90 can be rated at 90 A (Continuous), 120 A (Peak) when the best you can do is stuff an 8 gauge more like 10 gauge wire into it and solder?

To do ~90A onthe best rated copper wire it needs to be 4 gauge. How do you do that?
Maybe I am missing something here so if someone could enlighten me please do so.


image_hrpual.jpg

Wolf
 
You can do 90A on that wire.. Its all about the length.

in RC you have perhaps 5cm of wire or 10 at most ;) Its all about voltage drop in the end.
 
daromer said:
You can do 90A on that wire.. Its all about the length.

in RC you have perhaps 5cm of wire or 10 at most ;) Its all about voltage drop in the end.
Click to expand...

Yea I get that so as "long" as you don't get too long (of wire)its OK to use a smaller gauge wire.

Case solved
Thanks
Wolf
 
Wolf said:
Korishan said:
Also be aware that the XT90 can only do a max of 90A continuous, and that's if they are the legit connectors, and not knockoffs.
Click to expand...

I have always wondered how a (legit) XT90 can be rated at 90 A (Continuous), 120 A (Peak) when the best you can do is stuff an 8 gauge more like 10 gauge wire into it and solder?

To do ~90A onthe best rated copper wire it needs to be 4 gauge. How do you do that?
Maybe I am missing something here so if someone could enlighten me please do so.


image_hrpual.jpg

Wolf
Click to expand...

That's another reason I'm not a fan of the XT series. I think they're designed for total circuit runs no longer than a foot or something round trip, because the gauge wire they comfortably accept seems woefully undersized. That's great for small handheld packs in RC but would worry me for the larger packs with a much longer run. I'm sure it'd be fine for the most part but who wants their cables heating up in the wrong situation?

Edit: didn't read daromers response before opening my yapper. So 5 to 10cm seems much more realistic. But that does really limit the uses of the XT series.
 
OhmGrown said:
That's another reason I'm not a fan of the XT series. I think they're designed for total circuit runs no longer than a foot or something round trip, because the gauge wire they comfortably accept seems woefully undersized. That's great for small handheld packs in RC but would worry me for the larger packs with a much longer run. I'm sure it'd be fine for the most part but who wants their cables heating up in the wrong situation?

Edit: didn't read daromers response before opening my yapper. So 5 to 10cm seems much more realistic. But that does really limit the uses of the XT series.
Click to expand...

Ahh you can open your yapper anytime :D

The 5cm to 10cm is the combination I was missing to the puzzle. It would be nice for the XT connecter sellers to disclose that.
Maybe some of them do and some of it should be common knowledge. Sometimes you just scratch your head and wonder overlooking the obvious.
I still think to join my packs together in series as the wire length is very short I will probably use them (XT90) with as large of a wire as I can stuff into them reasonably and use 2 of them all in parallel so I would have (4) AWG 8 cablesI am hoping.But maybe AWG 10 to connect my packs is sufficient as 4 AWG 10 in parallel would be 120A anyway and the V drop and resistance would be minimal for the short length. For the end terminations of the pack 48V nominal + and - more than likely properAnderson connectors that accept large gauge wire for the longer runs.

Wolf
 
If you're pushing 52Amps continuously, you may want to use some thicker cable. AWG10 would get pretty warm.

Also, having more mass and surface area in the cable will help keep the connector cooler.
I'm stuffing in an AWG10 into an XT60 by trimming a few strands at the top. You could probably do something similar for the XT90.


image_rarzuu.jpg


image_igroaz.jpg


image_oqngao.jpg
 
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