WheelchairDriver

quadcopter wrote:

expresso wrote:Yes Scooterman - thats correct - i used two sets of cable on one ring lug - one set of cable is 10AWG with the fuse - thats going to the ADD ON Cable going to the Chair using 8AWG

So I don't need this second pair going to chair.

are you making a ADD On pack or a full chair pack ?

shirley_hkg wrote: Wonder how you insert 6awg cable in an Anderson SB50 pin.

I did not use an Anderson Powerpole SB50 on any of the 6 AWG cables, only on the 10 AWG cable.

There are pins available for a variety of wire sizes.

For example, this has 10 or 12 AWG pins: https://www.amazon.com/Anderson-Power-P ... way&sr=8-7

While this has 6 AWG pins: https://www.amazon.com/Anderson-Power-P ... way&sr=8-2

Steve

The most common SB50 pin is actually sized for AWG6

expresso wrote:are you making a ADD On pack or a full chair pack ?

Full chair pack.

I can use XT or Anderson connector for power cable.
What is difference? Or I can say which is better in your opinion?

quadcopter wrote:I can use XT or Anderson connector for power cable.
What is difference? Or I can say which is better in your opinion?

Anderson SB50 for power cable ends going to the chair power -

Revolectrix guys recommend use their Safety Banana Cable (CP8S-SBP18-40A-US). It has 2 x 40A fuses and 12 AWG cable.
They say: "At an 18 inch length, that wire should pass the max. charge rate of 40A without exceeding 130 deg F.
12 AWG is the largest diameter that the Safety Banana Plugs can accept."
So what sense and more important how we can use larger cables?

Those Revolectrix 12 AWG, fused, safety banana cables are exactly what I use.

I attached the 10 AWG main charging cables to them.

If I charge at 25 amps, the 12 AWG cables, particular near the fuses, get warm but not too hot for me.

When I charge at 30 or 35 amps, the 12 AWG portion of the cables, especially near the fuses, get too hot for my liking.

It is not a problem for me to charge at 25 amps, so this works well for me. If you want to charge at higher amperages, I recommend you consider at least 10 AWG for the entire run (and be sure to use fuses).

Note, I purchased two sets of the Revolectrix 12 AWG, fused, safety banana cables. I used one for the regular charging cable that terminates in a male 13W3 dsub connector. I attached alligator clips to the end of the other one and used it for the initial set of charging and discharging of the individual cells.

Steve

I charge through that sized cable at 40A all the time. They are silicone. Designed to allow a little heat. No worries! They get so hot in a model plane that you cant touch them, as we use that same cable at 100A plus!

Burgerman wrote:I charge through that sized cable at 40A all the time. They are silicone. Designed to allow a little heat. No worries! They get so hot in a model plane that you cant touch them, as we use that same cable at 100A plus!

Here good illustration of your words -
youtu.be/0DhzWPoSYoQ

At 100A that tiny 24 gauge wire was never going to survive! Also for those that dont understand this stuff, the volts dont matter in in cable sizes. So as you can see 12 gauge silicone is fine at just 40A. But not unless silicone. Cheap PVC cable, will soften even at 40A.

This tiny egg sized motor takes 130A and at 6S LIPO or about 25V. It is then a 3200 watt motor! Its loud, turns at 56,000 rpm, and is approx 4 horsepower. Its also tiny. Its a HET 2W20. That means its only got 2 heavy turns in the motor, that makes it super low impedance. And those windings are 20mm long.

Its used in my little racer. Known as F3D pylon racing. It uses that same 12 connecting gauge wire. But is air cooled.
Like this:

Same motor in a plane but only 4S... Ignore the windy slow start. Here it cant be flown fast because cloud too low. To fly it you have to see it...


youtu.be/FQ5WhNMm5bA

Pack interconnect cables have to pass max powerchair current (30A-50A continuous and 200A-240A in a peak). Am I right?

Yes. Seldom above 150A, but it can see 200 annd a bit intermittently for a few moments. Although very unlikely unless programmed like mine with all accelerations and decelerations at max. And driven like a hooligan.

Yes. Seldom above 150A, but it can see 200 annd a bit intermittently for a few moments. Although very unlikely unless programmed like mine with all accelerations and decelerations at max. And driven like a hooligan.

Would you say using 8 AWG wire for the interconnects is OK -

i used that size on my 80ah pack - and have used it on my 60ah Pack which been using for a year now - combined with lead - i dont recall but i may have used 10awg on the 60ah pack - - either way no issues so far with any of them - in the future i would not use less than 8 awg ?

I found battery interconnections here in Ukraine - https://energy-gmbh.com.ua/p12686054-peremychka-soedinitel-200.html
For example they have PVC cable with 16 mm2 cross-section area (in comparison 6 AWG has 16.08 mm2 cross-section area).
Can I use these interconnections?

expresso wrote:Would you say using 8 AWG wire for the interconnects is OK

Based on my research, I decided that 10 mm2 is the right size for interconnects between cells. I think I have seen BM recommend 10 mm2 as well, but he can confirm or deny.

Per wikipedia, 8 AWG is 8.37 mm2 and 6 AWG is 13.3 mm2. I really wanted 7 AWG, which is 10.5 mm2.

Unfortunately, 7 AWG wire and connectors are not readily available in the US. So, I settled on using 6 AWG.

I could not find tinned, copper 6 AWG wire with silicone insulation, so settled on some with PVC insulation.

Life would be easier if I lived in a country that used metric, like most of the rest of the world.

Steve

I remember a story about that regarding NASA... They crashed a probe into mars because they mixed up the metric and imperial system.

I got 3 cells (batteries) from 8. Others in transit yet.
They looks good - as new.
I measured voltage:
1 - 3.298V
2 - 3.301V
3 - 3.300V
Do I need to charge them?

Thats fine for storage.
You cant really tell the state of charge by voltage.

So you ideally would wait till you get the rest. Then charge all of them. Then assemble into a pack. Then charge again, this time it will be balancing them all to the same exact 3.600V ready to use.

The interconnect wiring will see the same current as the wiring between the pack and the chair... So in theory ought to be the same size as first approximation... However the interconnects are generally much shorter, so in theory lower resistance allowing for smaller wire - but I suspect the calculation (which I haven't done) wouldn't show a significant difference because the none of the wiring in a chair is what most would consider to be very long...

If you look at what comes on factory chairs, I've mostly seen AWG 10, sometimes AWG 8. Aside from a couple of Invacare chairs I saw mentioned here a few years back (and my Invacare H-frame project chairs used AWG 10) I haven't seen many reports of chairs having overheated wiring issues, so they seem to get away with it.... Their wiring is all poly insulation from what I've seen.

In addition to BM, the other 'extreme use' case I've seen is power soccer, and we had a member a few years back that was coach for the Team USA power soccer team that won the world championship that year (we'd like to think our advice helped... ) His opinion based on experience wiring soccer chairs was that AWG 8 was more than adequate for normal use, and OK for most soccer chairs, but that AWG 6 was marginally better at the highest level.... (and overkill for everyone else)

Since the most common SB-50 / PP-75 pin is sized for AWG 6, it is a bit easier to use, and the cost difference is trivial, I see no harm in overkill....

Also as far as I'm concerned, in general having a wire get noticeably warm is a BAD thing, as it means you are wasting power on heating the wire instead of doing actually useful work (not to mention reducing the amount of power reaching the work...) Better to use heavier wire if possible / practical....

I used welding cable - heavy poly insulation, and my feeling is that if it can stand up to the abuse that cables get in a welding shop, it is going to be fine on a chair where it's generally tucked away inside the frame....

I actually don't like silicone insulation for MOST applications as it is a bit more fragile and easily damaged than poly. I only like silicone in cases where the heat tolerance is needed because the wiring size is limited...

ex-Gooserider

swalker wrote:

expresso wrote:Would you say using 8 AWG wire for the interconnects is OK

Based on my research, I decided that 10 mm2 is the right size for interconnects between cells. I think I have seen BM recommend 10 mm2 as well, but he can confirm or deny.

Per wikipedia, 8 AWG is 8.37 mm2 and 6 AWG is 13.3 mm2. I really wanted 7 AWG, which is 10.5 mm2.

Unfortunately, 7 AWG wire and connectors are not readily available in the US. So, I settled on using 6 AWG.

I could not find tinned, copper 6 AWG wire with silicone insulation, so settled on some with PVC insulation.

Life would be easier if I lived in a country that used metric, like most of the rest of the world.

Steve

While waiting rest of my batteries (cells) I crimped terminals (hydraulic crimper used for AWG 6).



Also I want to add some solder and heat shrink tube.

Soldering is pretty much essential But how will you get the heatshrink on now?

Soldering is pretty much essential But how will you get the heatshrink on now?

I have shrink tube 10/5 mm (10 mm before and 5 mm after shrink).
I can get it on easily.

I want to charge my old MK gel battery.
I have Banana Plug to Alligator Clip.

What profile should I choose on PL8 charger?

What Ah battery?, 1 battery alone, 2 batteries in parallel, or 2 battery in series?

I will do a profile.

74 Ah, 1 battery alone.

remove .zip

If your cables are too thin for 25A charge reduce it to whatever you think they can handle. Maybe 15? Cant tell from picture. Dont worry if they get warm, but reduce it if they get hot.