Wiring harness ideas

Hi all,

I'd very much appreciate some direction. Here's the problem: my ebike, based on an em3ev kit with infineon 9-fet and 9C motor, has just turned 5. It's been 4 good years in which I commuted and ridden for thousands of miles. This year, it has been a bit dodgy and I'm taking advantage of the winter downtime to refurb. Issues encountered this year revolve around connectors. The battery-to-controller Anderson developed a bad contact around May - replaced with XT60s I had from another project. In July the on/off+regen 4-pin became a bit loose and when I tried to wedge it in, it crumbled; I direct-soldered the wires as I had to hop on the next day and so on and so forth.

Since all andersons seem to be giving up the ghost more or less at the same time, we can say they've reached their useful life. I'd like to replace the current botch of solder/modeling/failing andersons with a proper connector type that'll last 5 more years. Does it need to be metal/IP68? Probably not, but I value reliability over mass or cost.

I'm happy with the XT60 on the DC and the bullets on AC, so the amp-carrying ones are ok. On the signaling side I have full DC-bus voltage on the on/off switch ( 60V on that flimsy cracked piece of plastic on the handlebars?), the rest are all 5V. What do you use and advise to replace the signaling connectors with? I've built-up 22-pin souriaus , I'm not afraid of a bit of tinkering 8)

Many thanks for reading and give me your 2 cents

Unless it's something you think you'll need to service off the bike, or something you have to disconnect to be able to service the bike itself, just do a straight thru wiring, no connectors. There's nothing to fail, then, other than the wire and the connections internal to the devices.


So throttles, ebrakes, lighting, etc., can all be direct wired.

Power sources (batteries) may need connectors, but might be able to use bolt-on connections, depending on the design and construction of your system and bike. Either can be reliable or unreliable; depends on conditions/etc.

I personally have found that for up to at least 100A, the SB50 (or PP75) Andersons work fine. Genuine Anderson housings have been better than any of the various clones I've used, but I have a mix of them in-use. The genuine ones have more flexible but denser plastic; it appears to be a different *kind* of plastic than most of the clones (which are less rigid and/or more brittle). WIth this size contact in the SB50 housings, it's not as big a deal as with smaller PP45s, but the PP75s are affected to a degree somewhere between the two.

Springs on the non-genuine housings are not as strong as the real ones either, which means contacts don't mate as firmly and are not always forced to seat correctly. Worse in the smaller PP45s than their bigger versions.

I use these mostly because I have them, salvaged from various things like powerchairs, large UPSs, etc. But you can buy them new, too. I keep water out by filling the housings with dielectric grease (petroleum jelly), which gets messy in the summer here, with the extreme heat near the road surface, but the rest of the time is fine.


THe major limitation of Andersons is that the contacts must float in the housings; if the wire gauge/insulation is too large they wont' float and then the contacts may not sit flat, and excess resistance cuases various performance and longevity problems. Same for if the wires are twisted / stiff and cause contacts to twist against each other.



For small-signal connectors, if you need waterproofing, you can buy HIGO tails (thread in the for sale section, for instance), that you can solder to your existing wiring. Or whole wiring harnesses premade. They come in a variety of pin counts, and are small and keyed so difficult to plug in wrong. I have some, and was going to use them for my handlebar controls, but ended up just wiring that all directly (except for now teh throttle / pas stuff on the CA3, while I experiment).


My trailer lighting connectors are 5pin DIN, like MIDI or old AT keyboards, simply because I have them, and I've used them for this purpose since I started using trailers with handlebar-controlled lights on them. THey are not waterproof in anyway (and the housings don't lend themselves to the jelly trick well), so I sometimes have to replace them. I recently redid all the ones on SB Cruiser and the trailer I use with it, and they'll probably be good for another couple of years or more. I don't really recommend these connectors if you have better ones, but if you have access to them, then you have N+1 connections, where N is the number of pins, plus the outer shield if you want to use it for ground or whatever, and the contacts can carry a couple of amps or more easily enough, at 12-16v. (though if you are using existing cables from keyboards/etc they have VERY thin wires and are not recommended for anything more than small-signal controls).

Hi amberwolf, thanks for the advice. I did a bit of googling to unpack :thumb:

My old DC battery connectors were PP75, the battery to charger still has the same. I didn't know the name of them, so thanks for that. The HIGO I found that ship to the UK are a bit pricey. It may be that they are the ones to get, but I found some sort of an alternative in these M8/M12:
http://www.farnell.com/datasheets/1945922.pdf
There are some original knockoffs on ebay for a few $$$ a piece: ebay link

You have a point about having them soldered: this is the lowest contact resistance, best efficiency, cheapest and lightest and can be waterproofed with a bit of grease and heat shrink. The thing is I want to switch the system to a 700C-type frame, rather than the 26"-er I have now and may tinker with a sensorless controller from bmsbattery at some point The plan is during the year to downsize to a smaller more efficient motor and a smaller battery pack as technology has evolved a lot in the last few years (3.5Ah in an 18650 rather than 2.2Ah in my 22F )

food for thought

drebikes said:

My old DC battery connectors were PP75, the battery to charger still has the same.

Click to expand...

PP75s (PowerPole 75A contacts) are about the size of a pinky finger for the average adult hand, and are unusual to find on ebike stuff as it comes from manufacturers. Usually those are PP45s (45A contacts), which are about an inch long and a quarter inch wide (ish).

SB50s are dual-contact-housing versions of the PP75s with harder plastic on the housing, but same contacts, and different colors have different keyways on the original stuff (some of the clones use the grey housing keyway on all their colors). If the keyway between the contacts is cut out (dremel, etc) they'll all fit each other.

Most ebike stuff doesn't need anything bigger, but somewhere in my posts about SB50s there is a picture showing variations of the SBs up to the size of my hand, if you need a couple hundred amps or more continuous.

The HIGO I found that ship to the UK are a bit pricey. It may be that they are the ones to get, but I found some sort of an alternative in these M8/M12:

Click to expand...

Those look like a useful variation; I think I've actually seen them on some ebike stuff before, but thought they were just a HIGO variation (was about the same time the HIGOs started showing up in OEM stuff).

Keep in mind that knockoffs are going to go cheaper with everything, which typically affects which plastic they use first, and their molding techniques, so the housings get brittle faster, and may also not have the same tolerances so may not fit as well as the originals. (important if you're after the weatherproofing).

You have a point about having them soldered: this is the lowest contact resistance, best efficiency, cheapest and lightest and can be waterproofed with a bit of grease and heat shrink.

Click to expand...

It's really best if you run new wiring from inside one device to inside the next, without any splices at all, but unless it's for high current the losses in the connections are usualy minimal.

If you can crimp connections it's even better than soldering, but requires a good high-compression crimper to cold-weld the conductors, and most people don't have that and can't spend for one (like me); they're expensive and not worth it for one bike's worth of connections for most people.

The thing is I want to switch the system to a 700C-type frame, rather than the 26"-er I have now and may tinker with a sensorless controller from bmsbattery at some point

Click to expand...

That's the problem with experimenting--it's much harder to permanentize a bike setup and weatherproof it, make it look really good, etc. :/ But necessary in many cases to find the ideal setup, or when conditions change and the old ideal setup isn't anymore.

When money exists, it can be better to leave the old bike as it is, and make a new one for the new experiment. This also gives you a spare bike for when the experiment doesn't go as planned but you need transport right now.

Awesome. Two more days of thinking it over and I have decided to:
*give up on the idea of upgrading the frame. Turns out I'd need to spend quite a bit to get a meaningful upgrade
*buy a handlebar extension to fit the headlight and water bottle on the front. This would make space for other bits on the handlebar
*solder everything and waterproof with heatshrink/glue

Now I need to buy some spokes to fit the Q128C in a 26" rim, build the wheel and get to soldering.

Thanks

If you haven't already purchased the waterproof connectors... I love these for all my sensor wires.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F173170221449

They're amazing and they work great with the pigtails! Only problem is they're kinda a pain to solder to the original wires...


I swapped these out for my hall sensor wires and everything else basically. I ride in all conditions so I needed something absolutely waterproof and these are it.

They look pretty good, I may try them.

I am running direct soldered cables for now and TBH with the freezing temperatures I'm not adding many miles to the bike

I almost laced the Q128C in a new rim with some nice Sapim spokes. After this wheel is true and tested I'll look into the cabling again. It feels sometimes I'm just kicking the can down the road as I should take are of this. Direct soldered looks like a pretty good solution so far, let's see how they hold up.
If I were to go for these cables, as this seems the way to go, I'd solder them on the PCB directly. It doesn't make them justice to do a bodge between the current and these.

I too am in the no connector camp. The only connectors on most of my bikes are charge plugs, though 2 have bolt together ring connectors on the power mains and phases just because I didn't want the heat of soldering heavy gauge wires too close to other wiring. The initial wiring takes only slightly longer, and completely eliminating connector issues and better/easier waterproofing are huge benefits to me. I don't like fiddling with ebikes once they're up and running. I just want to charge and ride with as close to 100% reliability as possible. My only somewhat frequent maintenance item is putting air in the tires.

I kept using connectors, including the cheap ass white scooter plugs. But I live in a crazy dry climate, and kept moving shit from one bike to another constantly.

But what you want, max reliability on the same bike for 5+ years, solder it all, except for perhaps the plug from battery to controller.

For that, I found it handy to Y splice those big wires, and connect with double sets of andersons, or whatever you like. Connect the same one first consistently, and that one takes the spark. the other one remains cherry, and both carry half the current until one of them finally erodes.