Assembled Hi-Power LiPo battery packs - any interest?

[jonescg]

Update guys; I have placed an order for a stack of 4P boards to be made. This would yield a 20 Ah pack, so you would be able to get the voltage up pretty high and still have a decent capacity battery. They won't be in my hot little hands for another month, but I just thought I'd let you know the option was there.

Cheers,
CHRIS

[jonescg]

4P boards are in!

What does this mean? I can build you a 14s4p battery which weighs about 8 kg, stores 1 kWh and is just 252 mm long, 100 mm wide and 150 mm tall. It can be balanced effortlessly with a Hyperion 1420 balancer, and can be charged with a standard 58.4 volt KingPan style charger from Cell_Man or the like. You can even get 3 of method's 5S "Complete HobbyKing LiPo Protection Kits" and they solder right onto the packs.

All I need is for HobbyKing to stock more 40C cells...

[DALBYNATOR]

4P boards are in!

What does this mean? I can build you a 14s4p battery which weighs about 8 kg, stores 1 kWh and is just 252 mm long, 100 mm wide and 150 mm tall. It can be balanced effortlessly with a Hyperion 1420 balancer, and can be charged with a standard 58.4 volt KingPan style charger from Cell_Man or the like. You can even get 3 of method's 5S "Complete HobbyKing LiPo Protection Kits" and they solder right onto the packs.

All I need is for HobbyKing to stock more 40C cells...

Hi mate, just wondering where you source your Hyperion 1420's from?

Cheers, Tom.

[jonescg]

I don't stock them, but there are a few kicking around on ebay. There are a few hobby shops around the traps who sell them too, but from what I have read ebay stores are about as cheap as they come. You still need a decent power supply for them though, and these aren't cheap - at least another $80 for a high power 24 V supply.

[jonescg]

DeVires will be happy

All of Rodney's 40C cells have arrived so I will be able to start putting together a little video on how to assemble the packs from scratch. Perfect for those poor folks outside of Australia who wish to avoid double shipping costs.

I'm going on an overnight motorcycle trip next weekend, but the one after will be a good time to start.

Cheers,
Chris

[Rodney64]

Ordered and paid today for my elcon charger. 24S lipo fully charged on the bike in 1 hour. Exciting

[Spacey]

Kits for overseas buyers:

For the keen DIYer, I can send the boards and tinned copper to you. You can order the cells from HobbyKing yourself, and pay whatever shipping it comes to yourself. You will need to know what you're doing with a pair of big soldering irons, and be well prepared. I can guide in this area

For a 38 volt, 15 Ah pack like the one pictured, I reckon I could sell the kit minus cells for $80 plus shipping (which won't be much). Can't get over the high cost of cut copper...

If you made up some boards for A123 Cells you would make some money.

[jonescg]

Agniusm has already made up some sweet boards for A123s in a 1P setup. Tough to beat them. I have my own ideas for EIG cells, but they will be 2P, maybe 3P depending on the application.
On the LiPo front I hope to make a start next weekend

[amberwolf]

I have my own ideas for EIG cells, but they will be 2P, maybe 3P depending on the application.

EIG already makes hardware for their cells/packs that should let you parallel or series them, and stack them neatly and bolt into packs, from what I could see of the few pics posted here and there. When you next try to get an answer from them about 1000+ quantities, you ought to ask about the pack-making hardware, too.

[jonescg]

I don't think their system is as space efficient as it could be. Sure, to have a nice box to put them in is handy, but their terminations are bulky. I reckon I can do a better job

[Nuts&Volts]

I don't think their system is as space efficient as it could be. Sure, to have a nice box to put them in is handy, but their terminations are bulky. I reckon I can do a better job

I agree and they use more copper than they need to by zig zaggin across the packs to make the series connection instead of just flipping the cell terminals around. I think the actually packaging around the cells is about as good as you will get and still have some thermal safe guards. Either way the EIG cells are very volumetrically dense to begin with you dont have to worry too much about fitting them.

[amberwolf]

Hmm. Maybe you could just flip the cells over in the holders, with the tabs bent the other way? Then cut the zigzag bars so you're only using htem for clamping bits.

For bigger packs that need parallel groups *and* series, just do however many P you need first, with all cells in the same direction, and then series those groups flip-flopped to each other?

Then you would still have their nice-looking tray hardware and clamping interconnects.

I'm not sure which of several possible methods is best, but if you want easy-to-disassemble-for-repair packs, or easily reconfigurable packs, that hardware really looks easy to work with.

[jonescg]

Anyway, enough about their cells...

My cut copper has arrived so I shall get to work this weekend. Mmmm, love the smell of rosin in the morning...

[jonescg]

Just finished two of Rodney64's 6 packs.

Isn't this the most compact 15 Ah, 22 volt pack you've ever seen?



I still need to solder the balance leads in, as well as the 90 degree bolted terminations. But I was surprised at how quickly they come together. With a bit of practice I should be able to belt out a 24s3p pack in a day.

I have also taken about 3 gig worth of instructional footage, and while I could stitch it all together and upload it to youtube I might just wait for DeVries to chip in.

[Rodney64]

Looking good Chris. Will be interesting to see the top speed of the crystalyte h3580 with this 88 volt pack.

[deVries]

Just finished two of Rodney64's 6 packs.

Isn't this the most compact 15 Ah, 22 volt pack you've ever seen?



I still need to solder the balance leads in, as well as the 90 degree bolted terminations. But I was surprised at how quickly they come together. With a bit of practice I should be able to belt out a 24s3p pack in a day.

I have also taken about 3 gig worth of instructional footage, and while I could stitch it all together and upload it to youtube I might just wait for DeVries to chip in.

You know I'm ready!

Do you have a high-speed internet connection? Send me a PM, so we can get this transferred to me.

Thanks.

[Olly3012]

Hi jonescg hope you can help me out ay im stuck on battery choice and you look like the man, I have just purchased a CroMotor and 24 FET 4115 MOSFET 84-132V Freeway Speed Controller (max battery voltage 150V) i was thinking 6X 6S5P packs and under charge them may be built into 3 even sized packs (6S5P side by side) any ideas im in Tas a rough cost inc post cheers.

[jonescg]

Hi Olly,

So 36s all up? 133 V nominal charge at 150 volts? Can be done Depending on how you want the final size and shape I can make them in any arrangement you want. Three blocks of 275 mm x 100 mm x 150 mm? (LxWxH) would work easily, but would still require come cables joining the series connections.

These packs are awesome for their compact size and power. Energy density as better than A123s, about the only drawback is the cost and the fact that LiPo isn't exactly set and forget. Cost to you is about $1.10 per Wh, so at 36 x 3.7 x 25 Ah = 3330 Wh, or about $3600. The high cost is the fact that the cells need to come from HobbyKing in bulk orders (easiest way to get a lot of cells all at once). After customs, GST and shipping they work out to be 32% higher than the storefront price.

It still blows me away that the individual cells require less handling and labour than 4s hardpacks, yet cost more

Anyway, happy to help

[jonescg]

Rodney's pack is almost ready. Because of the dimensions of the Phasor bike, we couldn't just do one long block up and back (that would have been considerably easier) so we had to split the pack up into 4 x 6s,3p blocks. We can't load the whole lot in one go, so the sub-packs are loaded individually and bolted together using 90 degree terminations.



The pack measures 400 mm long, 150 mm high and 81 mm wide.



I just have to finish the last two 90 degree terminations and solder the balance leads on. And we're more or less done!

[Ricky_nz]

Nice!
How hot did the cells get when soldering the copper bars on?
Are you planning to cover the copper bars with some form of insulation, maybe kapton tape or similar?

[jonescg]

I have the irons on for about 10-12 seconds, and most of the heat stays in the copper block while the solder melts. The cells will only really get the last bit of heat as the solder on the tabs gets molten, and this is only quite brief. As the whole lot sinks down I take the irons off and dab it with a sponge and cold water. I always feel the cells afterwards to see if the got hot, but nothing does. The tops of the cells get a bit warm, but within about 30 seconds they are cold again.

And yes, for the mercy of Dog I will be insulating the terminations! I don't know what would be ideal, maybe Kapton tape or just a few rounds of PVC tape? I want the balance leads to stay out of the way as best I can manage.

[Ricky_nz]

I have the irons on for about 10-12 seconds, and most of the heat stays in the copper block while the solder melts. The cells will only really get the last bit of heat as the solder on the tabs gets molten, and this is only quite brief. As the whole lot sinks down I take the irons off and dab it with a sponge and cold water. I always feel the cells afterwards to see if the got hot, but nothing does. The tops of the cells get a bit warm, but within about 30 seconds they are cold again.

Sounds good

And yes, for the mercy of Dog I will be insulating the terminations! I don't know what would be ideal, maybe Kapton tape or just a few rounds of PVC tape? I want the balance leads to stay out of the way as best I can manage.

I would stay away from PVC electrical tape because it leaves leaves a horrible mess. Kapton tape might be better or even sheets of thin polycarb / lexan glued over the bars on each brick or group of bricks and then you could wrap the bolted connections in self amalgamating tape.

Edit: If you use clear lexan then you can show off your work! It would also give better protection to intruding objects than just tape.

[Rodney64]

Looking good Chris but I would be feeling better if I had a frame to put it in. How did the shed handle to storm. 150 high is that to the top of the terminations.

[ohzee]

hah yea Rodney I am jealous you sure are getting ready for the new bike.

Battery looks very nice. Makes me want one.

[jonescg]

Looking good Chris but I would be feeling better if I had a frame to put it in. How did the shed handle to storm. 150 high is that to the top of the terminations.

I had to leave and shut the door when the wind got too strong. I could see the roof lifting!

The majority of copper terminations are at ~143 mm high, so I figured 150 would account for the balance leads and Method's boards. The top of the bolted termination would be closer to 160 mm, but fortunately there are only 3 of them, and these are in the middle where clearance is greatest.