Heatsink useful for 15s3p Zippy Lipo battery pack?

I am going to build a 15s3p from 15 pcs 3s 5000mAh 20C Zippy packs. Two stacks of 5 pcs paralleled in 3 rows.

Is it beneficial to put aluminum plates between the rows or should I just sandwich the whole pack in an aluminum housing?

Attached picture shows arrangement with aluminum plates.
green: AL plates
blue: Zippy packs
white rectangles: 1"x.5" AL rectangular tubing milled to pack thickness

Heatsinking seems overkill for the 50A I am planning to get out of the pack but the sandwich assembly would not require any welding, just threaded rods through the plates and stand-off tubes.

View attachment Book1.pdf

Aluminium plates between cells in a battery is a technique that's used for cooling. Whether you actually need it or would benefit from it is doubtful, but it wouldn't hurt, as long as you be aware of potential problems of edge/corners of the plates chaffing against the cells.

I woldn't do that. The heat generated by a healthy 15s pack should be insignificant while the risk of punctures using metals is high. Unless your battery bag is a solar oven box and you live in a really hot área you don't need it.

Depends on the environment it will be used in. Youi won't want extra cooling if the battery pack starts the ride at 0 C temp.

I agree that if your 50 amps is burst amps, and mostly you cruise at lower amps, it should not be needed. The pack will get plenty warm, but not much warmer than ambient on a hot summer day. 15 ah x3c is 45 amps, so you should not be getting the packs all that hot. by above 5c discharge, you would heat those suckers up and kill them fairly quick. But you will max out at 3.3c or so. The pack would be even happier though, if you carried 20 ah.

If you do want the battery to cool to room temp faster once you bring it inside, before you start charging, then the heat sink will help with that. but the general rule is if you really need it, you needed a bigger capacity battery.

Don't use those packs. Everything in the zippy brand has been half as powerful as advertised in my experience. An aluminum plate will not cool the most vulnerable part of the pack, which is the cells in the center.

Your best bet is to spec the pack correctly for your application, rather than incorrectly spec it so that it creates heat you need to shed. This is easy to do with 20C packs.

I run my lipo batteries at 1/4th their maximum output and they never get even warm. They live long lives, deliver full capacity, and have tiny voltage sag.. no amount of cooling addition can give you all those benefits.

15S sucks too. It's neither Fish nor Foul for most eBike systems.

These continue to work great for me in 12S - https://hobbyking.com/en_us/turnigy-5000mah-4s1p-14-8v-20c-hardcase-pack.html But that's not quite the industry 48V (13S)

For hub motor systems 16S can work nicely if using custom aftermarket controller.

And yeah, Zippy brand has never been on my favorite list...

15AH x 20C = 300A max cont output / 50A load = 1/6th of the battery pack's maximum output.
If you go with Turnigy 20C, you shouldn't need cooling at all.

alpine44 said:

I am going to build a 15s3p from 15 pcs 3s 5000mAh 20C Zippy packs. Two stacks of 5 pcs paralleled in 3 rows.

Is it beneficial to put aluminum plates between the rows or should I just sandwich the whole pack in an aluminum housing?

Attached picture shows arrangement with aluminum plates.
green: AL plates
blue: Zippy packs
white rectangles: 1"x.5" AL rectangular tubing milled to pack thickness

Heatsinking seems overkill for the 50A I am planning to get out of the pack but the sandwich assembly would not require any welding, just threaded rods through the plates and stand-off tubes.

View attachment 1

Click to expand...

My LiPoly lives in a frame bag(w/controllers) and it doesn't get hot, even here in Az.
Forget the fancy ideas and focus on the LiPoly basics which most folks don't consider before they jump into LiPoly.
What is the LVC to be used? Here, 12S, matches the 42 V of most 48V controllers and provides the simple, fool-proof LVC a LiPoly powered ebike needs.
How do you plan to charge a 15S/3P pack? Break it every time to use toy balance chargers?? With the mess of wires this pack will have, the likelyhood of an accident is very real. Consider big bricks w/ a minimum of wiring configured no more than 2P. I use 4) MultiStar 6S/10Ah configured 2S/2P for a 12S/20Ah pack and bulk charge. No pack breaking, it's plug and play;

4) Battery Medics provide a way to ck. the cells and balance(rarely needed).
50 Amp discharge might be a bit much for a 15Ah MultiSar pack, but maybe a larger capacity pack, like 20Ah and above might handle it.
Zippy LiPoly SUCKS. Use Turnigy 25C for 15Ah pack, (20C ok for larger)if the MultiStars won't work for you.