The Cycle Satiator, universal charger for the enthusiasts

[mrbill]

[...] in December we had our resources redirected towards a 24V 15A model after receiving some potential OEM interest in a unit with those specs. [...]

Any chance that 24v/15A units might be available to the E-S community? Some of us are still running at that lowly voltage.

 

[mrbill]

After many normal charge cycles, I experienced a new power fault.

Using firmware 0.916.

Was charging a 70Ah battery (Samsung INR18650-29E, 7s27p) from 50% SOC to 100% SOC (or about 25.5v to 29.4v) at a rate of 4.0A. I confirmed that the charger started charging normally the night before. Sometime during the night, probably during it's bi-hourly cycle conversion, the charger triggered a power fault. According to the resting voltage of the battery it appeared that it hadn't been charged much before the fault occurred, maybe only one 1/2-hour cycle at 4.0A.

Since I still have a collection of Chinese 7A chargers, I wired up a couple of these in parallel and began charging at a higher rate. I attached the Satiator in parallel and began adding it's current to the charge as I have done before, so I know this normally works. The Satiator immediately went into fault mode with a "low battery voltage" error. The display indicated that the charger was hunting around for the proper voltage (swinging from 12.1v to over 30v), even though the other chargers were working normally. Battery voltage was a steady 26.5v at the time. I tried multiple times to start the Satiator after unplugging and re-plugging after a few seconds, but each time I got the same error.

Then I gave up for a while and went back into the house to inform folks I was planning to meet later this morning that I would be late (and to write this report), while the Chinese chargers worked.

A few minutes ago I went back into the workshop and connected the Satiator in parallel with the other chargers. This time battery voltage was 27.7v. The Satiator started up, adding its 8.0A of current to the mix without problem.

Maybe the power fault error didn't clear completely when I unplugged and re-plugged the first time because I didn't wait long enough, or maybe (less likely) the Satiator is more sensitive to power faults at 26.5 volts than it is at 27.7 volts.

This power fault error is particularly troubling because it occurs at times in mid-charge when the charger is unlikely to be monitored by the user, leading to an uncharged or under-charged battery when the user expects a charged battery and may not be able to wait around to complete a full charge cycle. This could be quite inconvenient when touring, something for which the Satiator with its compact, fan-less, vibration-insensitive design is otherwise well-suited.

I hope this bug can be squashed with the next release, or at a minimum, that the firmware constraints can be relaxed further to avoid this error. Perhaps the charger could clear a power fault error on its own after some delay and then attempt to restart the charge cycle.

 

[justin_le]

Any chance that 24v/15A units might be available to the E-S community? Some of us are still running at that lowly voltage.

Hi Bill, yes we'll be doing a small batch of these in tandem with the 72V pilot run, although in relatively smaller quantities. Because of the higher current levels it will have a cable/grommet assembly for the output leads rather than being connectorized like the regular voltage models, but otherwise should be just the same.

After many normal charge cycles, I experienced a new power fault.

Since I still have a collection of Chinese 7A chargers, I wired up a couple of these in parallel and began charging at a higher rate. I attached the Satiator in parallel and began adding it's current to the charge as I have done before, so I know this normally works. The Satiator immediately went into fault mode with a "low battery voltage" error. The display indicated that the charger was hunting around for the proper voltage (swinging from 12.1v to over 30v), even though the other chargers were working normally. Battery voltage was a steady 26.5v at the time. I tried multiple times to start the Satiator after unplugging and re-plugging after a few seconds, but each time I got the same error.

Can you clarify if you were unplugging the AC power and not the battery port? If you had an _actual_ power fault on the power stage, then you would need to unplug the Satiator's AC side for a good 20-30 seconds before the screen would go blank and the device would be fully turned off. The bus capacitors are quite large and will keep the unit running even without input power for a long while. If the AC is unplugged and replugged after just a few seconds, then an actual fault in the power stage wouldn't be cleared, which would be why (as you suspected) it's only when you came back later that it reset and worked fine.

If you can confirm that is the case, then it would mean that there was not just a firmware issue falsely reporting power fault errors, but something in the charging environment that changed suddenly causing a brief surge of current, as any step change in the load would do. You can get this for instance you are charging one battery, then you plug in a 2nd pack in parallel which is at a lower voltage and the moment it is connected there will be a step drop in the voltage causing a brief current spike. Or it could be that the massive parallel battery pack has such low impedance that when the current shuts down to zero and then ramped up again it experienced an overshoot. If that was the case then it's definitely addressable in firmware.

We can replicate a 70Ah 10s pack here at our shop by paralleling a number of ebike batteries, but I think that the lower 7S voltage could be exacerbating things. Let me know if you are able to reproduceably get this error to re-occur and we'll try to replicate it here and understand what is going on.

 

[mrbill]

Any chance that 24v/15A units might be available to the E-S community? Some of us are still running at that lowly voltage.

Hi Bill, yes we'll be doing a small batch of these in tandem with the 72V pilot run, although in relatively smaller quantities. Because of the higher current levels it will have a cable/grommet assembly for the output leads rather than being connectorized like the regular voltage models, but otherwise should be just the same.

Hi Justin:

Sounds good. I trust you will announce when these are available.

After many normal charge cycles, I experienced a new power fault.

Since I still have a collection of Chinese 7A chargers, I wired up a couple of these in parallel and began charging at a higher rate. I attached the Satiator in parallel and began adding it's current to the charge as I have done before, so I know this normally works. The Satiator immediately went into fault mode with a "low battery voltage" error. The display indicated that the charger was hunting around for the proper voltage (swinging from 12.1v to over 30v), even though the other chargers were working normally. Battery voltage was a steady 26.5v at the time. I tried multiple times to start the Satiator after unplugging and re-plugging after a few seconds, but each time I got the same error.

Can you clarify if you were unplugging the AC power and not the battery port? If you had an _actual_ power fault on the power stage, then you would need to unplug the Satiator's AC side for a good 20-30 seconds before the screen would go blank and the device would be fully turned off. The bus capacitors are quite large and will keep the unit running even without input power for a long while. If the AC is unplugged and replugged after just a few seconds, then an actual fault in the power stage wouldn't be cleared, which would be why (as you suspected) it's only when you came back later that it reset and worked fine.

If you can confirm that is the case, then it would mean that there was not just a firmware issue falsely reporting power fault errors, but something in the charging environment that changed suddenly causing a brief surge of current, as any step change in the load would do. You can get this for instance you are charging one battery, then you plug in a 2nd pack in parallel which is at a lower voltage and the moment it is connected there will be a step drop in the voltage causing a brief current spike. Or it could be that the massive parallel battery pack has such low impedance that when the current shuts down to zero and then ramped up again it experienced an overshoot. If that was the case then it's definitely addressable in firmware.

We can replicate a 70Ah 10s pack here at our shop by paralleling a number of ebike batteries, but I think that the lower 7S voltage could be exacerbating things. Let me know if you are able to reproduceably get this error to re-occur and we'll try to replicate it here and understand what is going on.

All packs were wired in parallel at all times. There was no new battery pack introduced or removed in parallel that might cause a step load. But, the power fault did present several times upon the first occasion when I added the Satiator in parallel with two other Chinese chargers that were each charging at 7 Amps. The second time, after the Satiator had been unpowered for about an hour, I introduced the Satiator to charge in parallel with the Chinese chargers, and the Satiator started its charge cycle normally, adding its charge current to the mix.

On the first occasion I had unplugged the AC mains until the display went blank for a couple of seconds, then re-plugged the AC mains. The battery port remained connected at all times. I didn't count the number of seconds between unplugging and replugging, but it felt more like 10 seconds than 20 or 30. I was assuming that when the display went dark the bus caps had discharged to the point of powering down the unit, but is this not so?

Even if I did not clear the error by fully powering down the Satiator when I discovered that my battery had not charged and was attempting to resume charging, my error does not explain the original power fault that occurred during a charge session that had started normally but had subsequently failed mid-charge while the charger was unattended.

I understand the need to treat faults conservatively, to minimize the probability of Type I error, not detecting a true fault condition that if ignored could lead to catastrophic failure. But, I suspect the constraints in firmware could be relaxed a little further. It might also be worth considering allowing the charger to automatically reset upon power fault after some suitable delay (like a auto-resetting thermal circuit breaker) so that spurious/temporary power faults, however small their probability of occurring, can be worked past but that true power faults continue to be observed upon each reset until the user intervenes.

I have a 70Ah 7s pack (actually three 23Ah packs wired in parallel) sitting at 50% SOC, just like before. I will run some trials later today or tomorrow and report back the number of times the charge cycle started with a power fault. I will take care that the AC mains are unplugged for 30 seconds between each trial.

Although I seldom use all batteries at once my total capacity is 133 Ah (51p @ 2.6Ah), and I have successfully charged them all in parallel with a single Chinese 7A charger. Would my testing for the incidence of false power faults be more helpful using the largest 7s pack I can assemble?

 

[district9prawn]

Is the generic power supply mode still on the cards?

 

[mrbill]

Firmware version: 0.916

Hi Justin:

I ran 50 trial charging session starts with a 7s 92Ah battery at 50% SOC connected to the Satiator. I started both 4A and 8A charges and stopped each charge when the current settled to exactly 4.0 or 8.0 Amps. In no case did I observe a power fault. When a charging session starts I can see the current spike briefly, then settle to about 1.0 Amps before ramping gradually up to the set current, overshooting by 0.2 Amps. Once or twice the current settled to 1.0 Amps and remained there for a second longer than usual before ramping up, and I thought I might then observe the power fault, but I didn't.

The power fault I experienced recently occurred mid-cycle, so maybe the Satiator does something different when it goes through its every-30-minute routine. Or, maybe there was noise on my AC line during that charging session.

If the Satiator does something different mid-cycle when it pauses charging, it may be necessary to upload a temporary firmware that reduces the period between pauses from 30 minutes to 1 or 2 minutes so that the misbehavior can be easily observed. I am willing to test this with my 7s batteries if you can send me such a firmware and if you think using 7s batteries is more likely to reveal the problem.

But, at this time I cannot duplicate the power fault.

 

[tomjasz]

The Satiator came with the anderson connectors. A very newly made affair, but the bottle "dolphin" style batteries EM3ev provides use a plug in the case that is quite different. The Satiator page reads that the battery can be charged using the battery output. Which is the preferred method? Using the battery port or the output leads. The most convenient method would be to use the case plug in, in which case I need to source the male connector. The question regarding the case connector is which is positive and which is negative, I can cut connectors off the OEM charger but I think I'd rather make an Anderson to OEM lead for charging.

Sound confused? I am...

Thanks,

Tom

 

[amberwolf]

On that battery, does it have a BMS?

Does the BMS have separate charge-cutoff (HVC) on the input, vs the discharge-cutoff (LVC) on the output? (if so, you should use the input or the BMS can't shutoff charge should there be a cell-level problem)

Or does the BMS use the same set of FETs (or whatever) to perform both cutoffs? (if so, either one provides the same protection)

 

[tomjasz]

The BMS limits the charge port to 2A. So I will set the satiator at 2A charge rate. I'm clueless about using the battery output. For now I made adapters using the cables from the EM3ev chargers to be used in the charger port at 2A.

 

[amberwolf]

The battery output is (probably) just + and -, so hooking up the charger to it + to + and - to -, it'd just work, at whatever the current limit for output is...except that if the charge-cutoff (HVC) is only on the input, then there will be no protection for the pack against a single-cell-overcharge situation.

(meaning, if there is a cell or cells that have different characteristics than the rest for whatever reason, and fill up faster than the others, that cell will be overcharged (and the rest undercharged) when the charger reaches it's full voltage, if there is no BMS-charge-cutoff (HVC) on the output and you use the output to charge with).

(if there *is* a BMS-charge-cutoff (HVC) on both input and output then it doesn't matter which you use to charge)

 

[tomjasz]

Got it! And I have to say it's a pleasure to have a device I can program direct from my MacBook. Hoorah! For Grin! Default set to match my OEM charger. Perfect. AND it did a better job of charing my SLS scooter battery, for whatever reason, they are better. Weird.

 

[neptronix]

Cycle satiator wiring is as follows:

white lead: positive
black lead: negative
other lead? i dunno, maybe a temp sensor.

You can unscrew the default connector and unsolder it, then solder it to something else pretty easy, keeping the supplied connector totally intact for later use if you think you might use it in the future.

 

[tomjasz]

Thanks, I just used the leads from the EM3ev charger. I solved my Anderson failure problem, insufficiently seated contacts, and simply made a splice and an adapter. Reprogramed a new default charge setting and am in business. I did find a pigtail UL rated for sufficient amperage rating (6-8amps max) to make a 6 or 9' lead for future reference.

Thanks again and again for the patience. Learning electronic terms and skills from a zero base as an old fart has been an adventure. The niggling details are sometimes overwhelming and I lose sight of common logic. I used to chide Vespa posters for not searching first and now find I need to chide myself when I get stuck. Unfortunately I often times lack the vocabulary to do an adequate and successful search. It's been an amazing year...

BiXPower-Y9-Cable-9-Ft-16AWG-DC-Power-Cable-with-5-5-x-2-5mm-Male-Connector

 

[Alan B]

I was wondering (without rereading this whole thread):

Any chance 2 of these chargers could be used in series ?

I asked the same thing when talking to Justin at last years Makers Faire and he said that they would indeed work in series.

Yup, but series connection would still generally require a mid-point tap on the pack. So if your 72V or 96V or whatever setup is made of two 36V or 48V packs in series, then each pack just has its own charging port and it will work fine. But if you have a single monolithic battery at this voltage without access to a mid-point reference tap, and then wanted series connect the satiator outputs into a single + - connector that is 72V, that gets quite a bit more complicated and wouldn't be recommended.

On my 18S setup I don't have a good midpoint to use.

What about series connecting the Satiator output with a 36V 320W Meanwell fanless potted LED supply. The Meanwell would just supply a 36V offset, at up to 8.9A so the Satiator would see a 36V lower battery voltage. That should get us to 36+45V = 80V at full 8A charge current, adequate for my 18S 75V packs.

The Satiator might see 81V momentarily if the Meanwell was off or slower turning on, so it would have to not fail instantly at that voltage.

 

[justin_le]

The power fault I experienced recently occurred mid-cycle, so maybe the Satiator does something different when it goes through its every-30-minute routine. Or, maybe there was noise on my AC line during that charging session.

If the Satiator does something different mid-cycle when it pauses charging, it may be necessary to upload a temporary firmware that reduces the period between pauses from 30 minutes to 1 or 2 minutes so that the misbehavior can be easily observed. I am willing to test this with my 7s batteries if you can send me such a firmware and if you think using 7s batteries is more likely to reveal the problem.

Hi Bill, OK yes this is exactly what we can do here and what I was going to propose. It might not be till next week but we will get a build for you that has a 2 minute tare interval and that way if there are incidents associated with it zeroing the current and then ramping up again we'd be much more likely to trigger the fault without waiting around for ages.

Unfortunately if there is an actual power stage fault, then there is nothing that the firmware can do in order to reset the device, since it's a hardware latch on the power circuit that only clears when the entire power circuit is turned off and on again. But we should be able to make it less sensitive by changing a few components around, if indeed that is what's going on here. If it's just a false reporting of a power fault and not a real one, then yes it would be sortable in firmware.

I was wondering (without rereading this whole thread):
What about series connecting the Satiator output with a 36V 320W Meanwell fanless potted LED supply. The Meanwell would just supply a 36V offset, at up to 8.9A so the Satiator would see a 36V lower battery voltage. That should get us to 36+45V = 80V at full 8A charge current, adequate for my 18S 75V packs.

You don't have to read the whole thread, it's mostly pages 2 and 3 where we discussed series connecting another supply with the Satiator to work at higher voltages.
Short answer is that if it's a proper constant voltage device with a higher current that the satiator, it should be fine, but as you surmised if the separate CV power supply turns off or is slow to turn on for some reason then the Satiator may see the full battery voltage on the output.
So the order would be to first make sure that your Meanwell is up and running, plug that to the battery circuit, and then plug in the Satiator. Then unplug the Satiator before you unplug or turn off the Meanwell.

I'm not sure if anyone has actually bothered to do this yet but it was certainly talked about quite a bit and should work just fine.

 

[Alan B]

Thanks Justin.

How much voltage can the Satiator temporarily handle on its output without failing (not putting out power, just not failing the output devices).

I'm just thinking about the edge conditions where things are plugged in and starting up, or there is a power outage during charging, etc. Nothing has to "work", it just has to "not fail". I'll reread the first few pages, thanks.

The 72V Satiator will be excellent, though adding a second supply would increase the charging power.

Thanks!

 

[Green Machine]

I had a question about the satiator.

Does it have any safety features to prevent user error when charging a battery.

For example if a user accidentally triggers the satiator to charge his 36 volt battery at 48 volts, does the satiator have any smart way of knowing the wrong setting has been selected? What would happen in this case?

 

[gelroos]

For example if a user accidentally triggers the satiator to charge his 36 volt battery at 48 volts, does the satiator have any smart way of knowing the wrong setting has been selected? What would happen in this case?

You'd likely destroy that 36V pack...

If you set it to shove 54V into that 36V pack, then your likely going to blow a cell at least, perhaps trigger a thermal event...

 

[cal3thousand]

I had a question about the satiator.

Does it have any safety features to prevent user error when charging a battery.

For example if a user accidentally triggers the satiator to charge his 36 volt battery at 48 volts, does the satiator have any smart way of knowing the wrong setting has been selected? What would happen in this case?

There isn't anything in the world that would do that without some work on your end.

But the Satiator does have some safety features that would help in this situation. For each profile, there is a (configurable) minimum voltage that the pack has to have before charging will proceed. If you set this 48V profile such that the minimum voltage will be greater than the 'full' voltage of the 36V pack, it would be near impossible to make the error. So if you made the minimum about 42V-43V for the 48V pack's profile, it won't charge a 36V pack if mistakenly connected

 

[mrbill]

I had a question about the satiator.

Does it have any safety features to prevent user error when charging a battery.

For example if a user accidentally triggers the satiator to charge his 36 volt battery at 48 volts, does the satiator have any smart way of knowing the wrong setting has been selected? What would happen in this case?

I can confirm that if I try to charge a 7s LiPo pack according to 14s charge profile, the Satiator gives an under voltage error and does not commence the charge cycle. This is probably because the Min Start Voltage for a Lithium charge profile is 50% of the full charged voltage. If I took a 10s pack and attempted to charge it according to a 14s profile, then I might have problems if the pack is not protected by a BMS. There was some talk of offering the option to terminate charge for lithium profiles by an over-temperature condition using the thermistor circuit (as with Ni packs), but I don't know if this has been implemented in the latest firmware version yet (0.916).

If this is likely to be a problem for you, you could create a profile for your 13s or 14s battery with the "Trickl Start" voltage set higher than 42.0 volts, which I admit is a pretty high floor, being about 3.2v/cell for a 13s pack and 3.0v/cell for a 14s.

 

[Green Machine]

Would it be hard to learn a trick from the rc chargers and have a temparture probe that you can stick to the outside of the battery pack...so in the event of a catastrophic error the battery does not catch fire and burn the building down? i know in my experience the thing that causes fires the most is someone plugging in the wrong charger for the wrong battery....why not make the satiator idiot proof and avoid fires? a charger sold for all batteries of all voltages of all different sizes (amp hours) seems like a disaster in the making if precautions are not taken to prevent a simple user error of causing a fire. I love the idea of one charger that can charge all my packs....but what if one night i get packs confused etc....i almost prefer having different chargers for every pack each with its own type of connector....then one charger that can charge it all and might cause a fire.

 

[amberwolf]

it's already there (at least the function is, as noted, for Ni chemistries, and possibly to be added for the rest of them).

 

[Green Machine]

I dont get it amberwolf...what function is already there? I am an idiot please explain, i am not one of those trying to pretend around here i have an engineering degree. . Does the satiator have an external temperature probe to prevent fires? Wouldnt an external temparture probe be great idea you just sticky to the battery pack before starting charing as a safe guard?

Wouldnt a charger with fire protection be a wonderful thing to the ebike community since most ebike fires are caused during charging? Is it possible i could start a fire by just selecting the wrong battery type on the satiator selector and pressing start....and making the mistake of having satiator and battery in my house? If there are no safety protections OR should i charge my bike outside on a concrete slab or or remove the battery and charge in a barbeuce grill? By the way...is the sataitor UL listed appliance? I understand i am treading on thin ice here.....but these are sincere questions....

.....what safeguards does the satiator have against user error. What if some amazing ebike engineerguy rides home one night after a few drinks, removes his battery, takes it into his aparment building, and accidentally presses charge with the wrong battery vaules in his satiator....can he potentially start a fire?

Just wondering...i am writing a review and trying to get info. By the way before everyone jumps on me i have wrote a glowing review on the satiator...i am just sincerely wondering about what built in safeguards it has before i wholeheartedly recommend it to the pubic.

 

[Alan B]

Hi Eric. The first posting of this thread answers many of your questions.

One technique for avoiding the "wrong settings" problem you mention is to bolt a Satiator on each ebike, then the settings are done once and it avoids making mistakes while changing them. Just plug in the AC cord and have only one set of settings programmed, or a couple of sets that are all safe for the battery.

Knowing the temperature at one point of a good sized lithium ebike battery pack may not be nearly sufficient to prevent overcharging. A sensor for each cell's temperature might be needed as the thermal conductivity of the pack is insufficient (or at least a number of sensors). A per cell voltage measurement is a much earlier indication of charging problems for simple overcharging. For packs with mechanically damaged cells the temperature sensor could be a useful indicator, but it would take many, and it is not clear that the temperature indication shutting off the charger is sufficient to prevent a fire in all cases.

Another way to avoid wrong settings is to put the settings on a chip in the pack, or an ID chip that the charger can read to select the right settings memory. Of course this requires one or more pins available on the charging connector, and not everyone is willing or can modify their pack to add this.

 

[mrbill]

Another way to avoid wrong settings is to put the settings on a chip in the pack, or an ID chip that the charger can read to select the right settings memory. Of course this requires one or more pins available on the charging connector, and not everyone is willing or can modify their pack to add this.

I think at this point it makes sense to put a good BMS on each of your packs. For all the extra effort to make sure each cell of a pack is adequately temperature-sensed, a good BMS will do more. That, and use cells that fail gently, not with fire or explosion. Even with these precautions one can never eliminate all risk.