AstroKat
100 W
Interesting. I read the first page of posts. I'm surprised the controllers don't include the basic circuitry to handle this and increase the draw slowly at first, even if just for a couple of seconds.
AW kit from Amazon
- Thread starter AstroKat
- Start date
LewTwo
1 MW
When you consider that all this began with lower voltages and currents then it is not much of a surprise. You do not get much spark from a 24 volt 250 watt system and a simple toggle switch can handle the power. As the power factors increase it becomes more of a problem ... one that has been largely ignored. Consider the difference between plugging in a 110 volt light versus the fuse links on the power distribution lines in one's neighborhood (where the utility workers use heavy rubber gloves and long fiberglass poles).AstroKat said:
Some of the more expensive controllers may include these provisions. I know the phase runner has a 'ignition' switch but I do not know how it is implemented. I can foresee these 'features' becoming a selling point for controllers. Manufacturers generally do not add features until it becomes an advantage to them (The public demand it or it gives them a marketing edge). Some people building more powerful system are known to include Circuit Breakers in their systems.
AstroKat
100 W
So, I just need a handlebar mount for this?
LewTwo
1 MW
You would still have arcing and sparking but it would be on your handle bars 
AstroKat
100 W
LewTwo said:You would still have arcing and sparking but it would be on your handle bars
That would be a "feature"...
999zip999
100 TW
How about a inline pre-charge resistor.
AstroKat
100 W
999zip999 said:
I've seen these referred to as a "solenoid" - I'm more familiar with mechanical solenoids.
Is there a "pre-charge resistor" that can be added, inline, to prevent the arcing but that does not interfere with the normal operation?
The precharge resistor would be on a third connector that makes connection before the main positive, and at the same time as the negative.
There are some connectors made with this already, like certain XT90s I think. Some have done it with a triple Anderson connector, and just plug in negative first, then the precharge into positive, then wait a few seconds, and unplug that precharge and plug in the main positive.
You can't leave th precharge inline with the main power directly, or it will also block main current flow (or heat up quite a lot with the waste power thru it).
But if you use a switch, you can always leave the precharge connected across it's contacts. Then you just plug in the batteries while switch is off, then wait a few seocnds to a minute (depends on size of resistor), then turn on your switch.
THere are a number of ways to do precharge, and there are numerous threads with that word in the title or first post that describe and/or show them. It can be a lot of reading, though.
Personally, I just use SB50 Anderson connectors, because they're designed with a sacrificial tip surface to take the arcing on connection, then as they continue to slide together for final contact the actual mating surfaces touch and this burned area is no longer part of the connection. All the other Anderson contacts are made the same way, but I like the SB50s cuz tehy are large enough for me to handle even when my hands aren't working right or if it's cold enough out that I have to wear gloves, impossible to connect wrong in the dark, and have enough contact force to not come loose unless you really intend to unplug them.
On my SB Cruiser trike (or the CrazyBike2) since it has *two* controllers (one for each motor wheel), there is quite the spark even at just 58v full charge, and I have welded PP45's together at the tips connecting them...but the SB50s are a wider contact surface so haven't had that issue yet.
Regarding controllers with built in precharge, there are a few--but they are all high-end (like for cars or car-sized power levels), there are some that specify you must use a precharge (kelly) but don't actually have one inside the controller. Some others (sevcon?) have logic inside for the "igniton" circuit to engage first a precharge and then a main contactor (since a simple keyswitch is unlikely to be able to handle the hundreds of amps those size controllers are meant to dish out).
There are some connectors made with this already, like certain XT90s I think. Some have done it with a triple Anderson connector, and just plug in negative first, then the precharge into positive, then wait a few seconds, and unplug that precharge and plug in the main positive.
You can't leave th precharge inline with the main power directly, or it will also block main current flow (or heat up quite a lot with the waste power thru it).
But if you use a switch, you can always leave the precharge connected across it's contacts. Then you just plug in the batteries while switch is off, then wait a few seocnds to a minute (depends on size of resistor), then turn on your switch.
THere are a number of ways to do precharge, and there are numerous threads with that word in the title or first post that describe and/or show them. It can be a lot of reading, though.
Personally, I just use SB50 Anderson connectors, because they're designed with a sacrificial tip surface to take the arcing on connection, then as they continue to slide together for final contact the actual mating surfaces touch and this burned area is no longer part of the connection. All the other Anderson contacts are made the same way, but I like the SB50s cuz tehy are large enough for me to handle even when my hands aren't working right or if it's cold enough out that I have to wear gloves, impossible to connect wrong in the dark, and have enough contact force to not come loose unless you really intend to unplug them.
On my SB Cruiser trike (or the CrazyBike2) since it has *two* controllers (one for each motor wheel), there is quite the spark even at just 58v full charge, and I have welded PP45's together at the tips connecting them...but the SB50s are a wider contact surface so haven't had that issue yet.
Regarding controllers with built in precharge, there are a few--but they are all high-end (like for cars or car-sized power levels), there are some that specify you must use a precharge (kelly) but don't actually have one inside the controller. Some others (sevcon?) have logic inside for the "igniton" circuit to engage first a precharge and then a main contactor (since a simple keyswitch is unlikely to be able to handle the hundreds of amps those size controllers are meant to dish out).
AstroKat
100 W
amberwolf said:
That makes sense, thanks! So once the main positive connection is made it's no longer in line, it's in parallel, and not interfering. Wow, this is turning out to be quite a fascinating experience...
999zip999
100 TW
Care for the catnip.
AstroKat
100 W
Yes, but I don't inhale... :wink:
AstroKat
100 W
OK, so here's the latest...
I went looking for other controllers for a variety of reasons. On my road test it was quite apparent that the motor was more than powerful enough for my teen, even with the issue of the low voltage cutout at the higher assist levels. He weighs 50lb less than me and I was able to easily get up to 25mph on a flat road, and climb steep hills with no pedaling. Then there's the issue of the new California regulations...
The AW controller does not appear to be switchable, so I was thinking of getting a 36v or even a 24v controller. However, I wasn't sure it would work with the current kit and their tech support is non-existent. It took me three days to find what might be the manual for the LCD on a different site...
One of the sites I checked out was Luna Cycle (thanks to a referral here) and they had a deal on a 750w geared kit for $275, with an LCD and a 36v/48v controller. They are close to where I live (in Los Angeles terms) so I went out to Gardena and picked up the kit, to save shipping.
All of the components appear to be very well made, compared to the AW kit. The connectors are also much better, and waterproof. The motor spins much more smoothly. For $50 more (albeit for a 750w "legal" kit, compared to a 1000w kit) it's a much better deal.
With a 48v pack the SLA batteries are still dropping to below 40v under load, and the controller cuts out. I have the watt meter inline now and have never seen more than 450w before it dies. I've started a dialog with the battery supplier (Beiter DC Power on Amazon) to get "fresh" replacements. I'm sure we'll end up with Li-Ion at some point but I'd like to continue the experiment and it's a great learning experience for us.
FYI, the folks at Luna Cycle have been great, both pre-sales and support. One of the buttons on the LCD doesn't work (I seem to be the guy who gets the one-in-a-million" defective part) and they responded quickly that they would send a replacement.
I went looking for other controllers for a variety of reasons. On my road test it was quite apparent that the motor was more than powerful enough for my teen, even with the issue of the low voltage cutout at the higher assist levels. He weighs 50lb less than me and I was able to easily get up to 25mph on a flat road, and climb steep hills with no pedaling. Then there's the issue of the new California regulations...
The AW controller does not appear to be switchable, so I was thinking of getting a 36v or even a 24v controller. However, I wasn't sure it would work with the current kit and their tech support is non-existent. It took me three days to find what might be the manual for the LCD on a different site...
One of the sites I checked out was Luna Cycle (thanks to a referral here) and they had a deal on a 750w geared kit for $275, with an LCD and a 36v/48v controller. They are close to where I live (in Los Angeles terms) so I went out to Gardena and picked up the kit, to save shipping.
All of the components appear to be very well made, compared to the AW kit. The connectors are also much better, and waterproof. The motor spins much more smoothly. For $50 more (albeit for a 750w "legal" kit, compared to a 1000w kit) it's a much better deal.
With a 48v pack the SLA batteries are still dropping to below 40v under load, and the controller cuts out. I have the watt meter inline now and have never seen more than 450w before it dies. I've started a dialog with the battery supplier (Beiter DC Power on Amazon) to get "fresh" replacements. I'm sure we'll end up with Li-Ion at some point but I'd like to continue the experiment and it's a great learning experience for us.
FYI, the folks at Luna Cycle have been great, both pre-sales and support. One of the buttons on the LCD doesn't work (I seem to be the guy who gets the one-in-a-million" defective part) and they responded quickly that they would send a replacement.
AstroKat
100 W
I just let the air out of the tire on the wheel to return. All of our cats fled…
My partner replied: "It must be one really huge badass angry cat..."
My partner replied: "It must be one really huge badass angry cat..."
Takemehome
1 kW
999zip999 said:
Here is my solution. Works for me at 60V less than 30A. ( using cheap DPDT AC switch rated 125V 20A )
Sorry I don't remember R value.
AstroKat
100 W
AstroKat said:
It's moot - the older battery won't hold a charge, even though it was never used (it even has the plastic protectors on the terminals). They certainly degrade quite quickly while stored...
I can get a 6v 7Ah SLA for around $12 to add in series. Fully charged, that would be over 57v. Here's the kit, which says it's compatible with up to a 52v battery: https://lunacycle.com/geared-hub-ebike-kit-750w-for-front-or-rear/
How much voltage can a 52v controller handle?
LewTwo
1 MW
You can figure that some the components are likely rated for 60 or 63 volts MAX. You need to stop thinking about Automotive starter batteries and start thinking in cells and chemistry.AstroKat said:
The SLA battery pack will have (4x6) + (1x3) = 27 cells in series. That gives you a voltage range of about (27x2.2) = 59.4 down to (27x1.8 ) = 48.6 volts if everything is perfect. Your real top end voltage is likely to be a tad less as the cells are neither brand new or in perfect condition at this point. Draining the cells down much below 1.8 volts will likely damage the cells.
By the way ... note the comment in the message that proposed this solution.
AstroKat
100 W
Well, I'm thinking that now I have a 36v capable controller, I'll try three 10Ah batteries instead (there's a three pack on Amazon for $59). Only slightly more watt hours but maybe they will handle the current draw better. And I can add a fourth if it's not powerful enough for hill climbs. Still a fraction of the cost of lithium for this "experiment".
Btw, the return label from "AW International" arrived and the return address is Yescom!
Btw, the return label from "AW International" arrived and the return address is Yescom!
wesnewell
100 GW
Find someone close by that does rc and see if you can borrow a 10-12s string of rc lipo to test. You're just wasting time and money with sla. A 5ah 12s lipo pack can be had for $45 on sale. Might try craigslist for some used stuff. My 5 year old lipo with 15K miles on it will outperform new sla by a long shot, and still last longer.
LewTwo
1 MW
Increase Volts for speed (series). Increase Current for Power (parallel).AstroKat said:
Do tell ... not a big surprise.AstroKat said:
999zip999
100 TW
lead is DEAD. It is useful as a 3-5 sec car starter battery after that the alternator. keeps it fully charged till you use the starter again. Stop wasting your money...
AstroKat
100 W
OK, everyone breathe...
Yes, I realize that SLA batteries are not the latest technology and that they have their own issues. So do LiPos (I have a LOT of LiPos).
SLA's are very economical for experimentation, by orders of magnitude compared to Li-Ion packs.
If anyone can propose a similar Li-Ion solution, at a similar price point, then I'm willing to try it.
I now have the 750w geared motor running on the 7Ah SLAs, at 805w peak...
Edited to add: Up to 1013w if I spin it up, then apply the brake and the throttle at the same time...
Yes, I realize that SLA batteries are not the latest technology and that they have their own issues. So do LiPos (I have a LOT of LiPos).
SLA's are very economical for experimentation, by orders of magnitude compared to Li-Ion packs.
If anyone can propose a similar Li-Ion solution, at a similar price point, then I'm willing to try it.
I now have the 750w geared motor running on the 7Ah SLAs, at 805w peak...
Edited to add: Up to 1013w if I spin it up, then apply the brake and the throttle at the same time...
Voltron
1 MW
You're not wrong... while you're trying to figure out how much voltage and power you need, and if you like a particular motor or not, they're an ok prototyping setup. It's easy to say the lipos are cheap, but by the time you add up connectors, RC chargers, paralleling harnesses etc, it can be cheap and simple in the short term to use lead. Also not bad for getting your first big sparks out of the way. Plus when you get your lithiums finally, they really really seem like a wondrous miracle of light weight and power.
AstroKat
100 W
LewTwo said:
Not much more to tell. This post began when I had some questions about a kit I purchased on Amazon from, and branded by, "AW International". Maybe "AW International" is Yescom's presence on Amazon? It seems there are hundreds of versions of the same kit being sold online, with only subtle differences between suppliers.
AstroKat
100 W
Voltron said:
I already had a lot of the RC gear but I'm wary of LiPos for a bike, due to the special handling required. Li-Ion battery packs seem to be orders of magnitude more expensive than SLAs, even mass-produced lawn mower batteries.
Thank you for the vote of confidence. I can't wait to get into lithium...
999zip999
100 TW
Time to save up for a Luna pack. He's local. Name brand cells.
