Enersys Cyclon Feedback

[Sunking]

12 Volt,,, LED night-light



Thank you for the input.

Based on Cyclon's questionable cycling capability, and high cost,
I've scrapped the idea of designing a post lamp with the battery and controller hidden & secure "in" the post.

Have you thought about LiPo or cylindrical LFP?

You can get 3S or 4S LiPo up to 6 AH and the package should fit in a pole. Think of RC plane batteries. Here is an example.

[Shockah]

How much voltage do you need?

12 Volt,,, LED night-light

As I said before the Cyclon line is a great battery, but not really intended for cycle service.

Thank you for the input.

Based on Cyclon's questionable cycling capability, and high cost,
I've scrapped the idea of designing a post lamp with the battery and controller hidden & secure "in" the post.

[PNjunction]

By far the simplest would be the taper charger, that is nothing more than a full wave rectifier, a smoothing cap on the output, and set for around 2.27v. Just don't exceed C/50 charge current. That would appear to be something you could just set and forget for the most part if your needs aren't critical.

[bcroe]

Charging Goals

You want Constant Voltage charging, where you set the upper voltage limit in the charger

You DONT want to run constant-current and let the voltage rise very high

As much as your charger has available while in the bulk stage. I wouldn't use
anything larger than a 25A charger on your 25ah cell, so you don't exceed 1C

I'd suggest not going below 2.0V.

You can get much more detailed charging procedures from the application
manual link at the bottom of this page:

http://www.enersys.com/Cyclon_Batteries.aspx

Quick note about what Enersys defines as the difference between cyclic and standby use:

This should be enough info to design chargers for several appliances here, or check
that the one it came with is adequate, thanks. I want to just plug stuff in indefinitely
and not worry about the treatment of the battery.

I note a portable audio amp here has a nice charging indicator. A red LED flashes very
rapidly so as to appear constant at the beginning. Then it tappers off to slower and slower
flashing, finally stopping. I wonder if its tied to decreasing charge current? Bruce Roe

[PNjunction]

OK for just riding through occasional power glitches, the 2.27V float should cover it. For
equipment needing a quicker recovery, the charger should start at 2.45V and then drop
down to 2.27V when current drops to .01C.

That will cover it more or less. However, depending on the age of your cell, you may never reach .01C in absorb, so it may be wise the first time out to merely watch for no significant change in current during a 3 hours period once into the absorb stage. You don't want to hold it at the absorb voltage longer than necessary. That would accurately define your REAL absorb current to then switch to float. Then just hold it there in float for 12 hours or so.

If I set the voltage, the battery will set the current. If I limit the current, the battery will control the voltage.

You want Constant Voltage charging, where you set the upper voltage limit in the charger, and merely let the charger provide as much current as it is capable of - within reason. You could run a 1A charger, or a 25a charger - makes no difference to a Cyclon, other than getting to absorb really faster and shortening overall charge time. You DONT want to run constant-current and let the voltage rise very high - Enersys warns against this unless you have no choice and are under very tightly controlled circumstances.

Occasionally you'll see references to CC/CV, which the "CC" part is just that initially during bulk, your charger is putting out as much current as it can constantly, and once the CV point is reached, then the charger merely puts a hold on the upper voltage limit, and now the battery will absorb what it can with that voltage limitation and current drops away which is a natural reaction of the battery doing the actual current control, and not the charger. The ONLY thing it is doing is limiting voltage at this point.

What level of current might occur after discharging a 25AH cell?

As much as your charger has available while in the bulk stage. I wouldn't use anything larger than a 25A charger on your 25ah cell, so you don't exceed 1C, but they are capable of taking much more. If you have the time and no need to recharge in 30 minutes basically, you can use lower amperage chargers. Just make sure they have an upper voltage limitation of 2.45v for cyclic charging, or 2.27 for long term standby charging.

Load current will be low, so can the level of discharge be estimated from V? What is a good low cutoff V?

It all depends on Mr. Peukert, but for general purposes I'd suggest not going below 2.0V.

You can get much more detailed charging procedures from the application manual link at the bottom of this page:

http://www.enersys.com/Cyclon_Batteries.aspx

Quick note about what Enersys defines as the difference between cyclic and standby use:

If you don't have two successive charges within 30 days, AND those two successive charges are not less than 14 days in between, then you are in a standby environment. In this case, just using a simple 2.27v CV charge would be fine. Otherwise, use the 2.45v until finishing absorb, and then the 2.27v float for many hours.

Real world - since I'm not a commercial site with mega-millions tied up in batteries, I'll just charge up to 2.45v, finish absorb, and float for a few hours no matter what, and accept the loss of cycles that may result. With my usage, I'll probably never see the difference, and the battery will just calendar-age faster than any non-perfect charging setup would degrade cycle life.

Solar is a different story - I just set BOTH my absorb and float to the same value, in this case 2.45v per cell, and call it a day and just get in as much as I can, since there is no luxury of long floats during the day.

[Sunking]

OK for just riding through occasional power glitches, the 2.27V float should cover it. For
equipment needing a quicker recovery, the charger should start at 2.45V and then drop
down to 2.27V when current drops to .01C.

That is not how a Float Charger works. A Float Charger is a constant voltage, current limit device. The current limit can be as high or low as you want within tolerance of the battery charge acceptance. Grabbing numbers out of the sky lets say you have a 10 volt 10 AH battery, and a 10 volt 1 amp float charger. So let's say the battery is completely discharged and you connect the charger. For about 10 hours the charger will supply 1 amp until th ebattery terminal voltage reaches 10 volts. At that point the current twill taper off toward zero amps after another couple of hours of a saturating charge, aka Absorb. The charger will hold the battery at 10 volts supplying only enough current to over come the self discharge current of the battery.

This is the basic operation of any Stand-By Battery service which is exactly what, UPS, utilities, and telephone companies use on their battery plants. It is the kindest most gentle charger there is and provides the maximum battery life. It only has one disadvantage of being slow to recharge. A 3-stage from dead to full is around 16 hours with a C/10 charge current. Float with C/10 will be around 20 to 24 hours.

Note Telcos, utilities, and UPS use much higher charge currents in excess of 1C. But they do not use the same kind of batteries you do.

[inetdog]

If you go float-only, you need to also limit the current to whatever would be safe during the bulk phase.
In other words, do not use too stiff a supply for the float voltage.

[bcroe]

Bruce that is easily done with a Float Charge. A float charger is as good as
it gets. The cyclone is designed for for Emergency Standby Service and a Float Charger.

OK for just riding through occasional power glitches, the 2.27V float should cover it. For
equipment needing a quicker recovery, the charger should start at 2.45V and then drop
down to 2.27V when current drops to .01C.

If I set the voltage, the battery will set the current. If I limit the current, the battery will
control the voltage. What level of current might occur after discharging a 25AH cell?

Load current will be low, so can the level of discharge be estimated from V? What is a
good low cutoff V?

Bruce

[PNjunction]

Sunking is right for standby float. If you are going to do that, you do so at 2.27v per cell.

If your charge current at 2.27v is only 0.01C, then a minimum of 22 hours is needed.
If it is 1C, then 6 hours would be the minimum.

Just be sure you are actually doing a standby service - do not use this for rapid cyclic service.

It should be mentioned that with option #2 mentioned above where you look for 3 hours of stability to stop the charge, you would actually set it just a little bit higher to allow for degradation between measurement periods, and especially in the case of multi-cell batteries where you don't have access to each cell.

Ie, if you notice your cell stabilizing at say 43ma over a 3 hour period, then if you use that with a solar charge controller, then you would set it a bit higher, say 65ma, to give yourself some headroom.

One can see why LiFePo4 is much easier to maintain than AGM! And, since agm was a major driving force behind EV's a few decades ago when the battle raged between NiMh, one can see that true officianados couldn't cope with that simplicity, and hence were overjoyed to wrap their battery banks with a rat's nest of wiring to get to this level of monitoring - they couldn't get past the lead-acid mentality of it all. Homebrew bleed-off boards and other methods of active-balancing were popular way back then too, (See the EVDL archives) and dutifully killing large high-voltage banks of Optima and Genesis agm's when they failed. I'm not trying to disrespect the EV community, but just noted that we've been down this road before.

[Sunking]

[QUOTE=bcroe;116419]Thanks for that info. There is a lot of stuff here with such batteries (mostly needing
new cells). Being decades old, the chargers are extremely crude. Like, "plug it in
for a while after use". I'd like to leave it plugged in continuously, to be ready and
to preserve the batteries. /QUOTE]

Bruce that is easily done with a Float Charge. A float charger is as good as it gets. The cyclone is designed for for Emergency Standby Service and a Float Charger.

[bcroe]

Thanks for that info. There is a lot of stuff here with such batteries (mostly needing
new cells). Being decades old, the chargers are extremely crude. Like, "plug it in
for a while after use". I'd like to leave it plugged in continuously, to be ready and
to preserve the batteries.

This stuff will tend to be perpetually on standby, but I don't want to forget about it
and ruin the batteries. There is already a system for the many lead acid batteries
around (standby generator, extra cars, etc). Since the float will be continuous, I'm
thinking of just cutting off absorb current at 0.01C and dropping to float 2.25V.

What kind of current might flow at 2.45V, after considerable discharge? My thinking is
rectify about 10 VDC, then switch buck regulate down to the desired charging voltage.
So the charge current will be pretty smooth. Load current probably won't exceed 0.1C,
so can the level of discharge be estimated from V? What is a good low cutoff V?
Bruce Roe

[PNjunction]

I follow either one of these two rules from the 1999 Cyclon users guide:

These assume a temp of 25C, and are a compromise between fast charge cyclic, and standby/float applications. Which is perfect for me, since I sometimes cross the line between the two.

1) Charge within 2.45 - 2.50v until current drops to 0.001C (zero, point zero zero one), then float for a few hours at 2.27v. Terminate charge. Note that 2.45v is the Minimum, no matter how much current you feed into it.

2) The better choice: Charge within 2.45 - 2.50v, until the absorb current has stabilized without much change for 3 hours. Terminate charge. By not seeking a specific "end-amps" as in the choice above, you are taking into account the cells age, internal resistance changes, and so forth. Again, 2.45v is the minimum, regardless of inrush current.

I apply #2 to my other types of agm's as well!!

WHY ??

Because option #1 may only be reached when a cell is very new. Ie, for your 25ah battery, that meant an end-amp absorb current of only 25ma (twenty five milliamps). For years I had been seeing references to using 0.01C, or about 250ma in this case, which really meant UNDER-charging, despite the few hours of followup float.

Option #2 was a watershed moment - it was the only one that took into account a batteries health over time, and not just a static value! For instance, in a year or so, as the cells age and dry out, you may NEVER reach 25ma of absorb, and end up cooking your cells attempting to get there. By watching for no real change over the course of 3 hours, you would charge properly and not dry them out.

But option #2 is hard to set with a solar charge controller that may rely on end-amps. So what should one do? Perhaps yearly, perform this charge on the bench, and record the stabilized absorb current value, and change your controller's "end amps", to either terminate or drop to float on that new current setting. This will help you stay in accord with the battery's own health as it ages, and not dry it out prematurely.

Or, you could just wing it, set your end-amps to 0.01C, and undercharge your batteries in the beginning of their service life.

Enersys really knows what they are doing, but I must admit, most consumer's eyeballs would glaze over if they read the manual, so you will see some simplification in later versions. Perhaps many of the consumers had no way to measure charge current reliably during the absorb stage. (Note - early manuals described intermittent charging - which was discovered to be really bad, so IGNORE that section in the 99 manual!)

[bcroe]

How much voltage do you need?
As I said before the Cyclon lin eis a great battery, but not really intended for cycle service.

I have one of these, 2 volts at 25 AH. Using it to replace a lead acid cell, which seems to
no longer be available, and I don't mind getting rid of vented acid. Just how should
charging be regulated? Could charge at 10A, and go to float (2.25V) when the terminals
reach 2.45V. I expect to be charging with pure DC.

Or should terminals be pushed toward 2.45V with unlimited current, and then switch to
float 2.25V after charging current drops to near zero? Bruce Roe

[PNjunction]

The only reason I am intrigued by these expensive Enersys Cyclons is so I can hide them in the post...
but if they cost 5X as much and are more temperamental to charging routine, then maybe I should use a bigger post to hide the cheapo battery

Sounds like a plan! Aside from the form factor, you are paying for a feature you won't be really taking advantage of when it comes to high current handling.

But they really aren't more fiddly about charging - it is just that many people chronically undercharge their agm's, but if they are cheap enough, from a practical standpoint it may be easier to simply replace them more often. With the Cyclon's, they know you are paying big $$ for them, and they want to at least make you aware of the need for proper agm charging - and also to make sure that some lab-rat like me or major commercial customer won't come back for a warrantee replacement when they only provide 50 cycles less than spec due to my charging routine.

Personally, I'd have a go at it because you are not deep cycling them, they will sit somewhat near 75-80% SOC when not in use, and if you use a 50-60w panel, it is likely you will get reasonable life from them, even if they are not being charged perfectly - I have a feeling that mere calendar life may limit you more than not obtaining a perfect charge. If you don't use them for perhaps just one day a week, that would be a nice compensation. You just might beat the cycle/life clock. You could even take it conservative, with a 14.7v absorb, and a 14.4v float with an adjustable cc. Just remember that before placing the battery in service, to do a good charge with a looooong float on them. Could you at least beef the panel up to 60W ?

Put this on the back burner - what I'd do is stuff four Headway 10ah 38120 lifepo4 cells in series inside the tube. They can handle up to 80% DOD and get 1500+ cycles - more if your DOD is less. Set your CC to 13.8v absorb. Disable float, or set it to something benign, like 13.5v. No temp comp needed. No need to reach 100% SOC. No sulfation. Partial SOC operation is just fine. Put your lights on the CC's LVD for a 12.8v cutoff. Done. Use a single-cell lifepo4 charger - even wall-wart size would do if you wanted to play with manual balance, and then leave it alone once balanced.

[Sunking]

How much voltage do you need?

As I said before the Cyclon lin eis a great battery, but not really intended for cycle service.