Iota Engineering IQ4 option

cosmicray · July 2014

I'm trying (really hard) to understand the Iota IQ4 option, and exactly what it does (or doesn't do) in my situation.

I'm on the grid, but my internet broadband connection is off the grid.

I am powering two Ubiquity wifi radios off a pair of 6V golf cart batteries, wired in series, producing 12V. The specific location where the radios are located has no grid power. Every so many days (currently 10-11) I pull the batteries and charge them up, which brings us to Iota's IQ4. The charger I have been using (a NAPA consumerish grade which has a deep cycle option) is not doing the job. The specific gravity check, after a charge and a battery rest, tells me this clearly. The batteries are relatively new (3 months) but are only reading a SG of 1.23 after a 14 hour charge. Plenty of fluid in the cells, voltage looks OK, but the specific gravity shows barely into the mid-scale, and not even close to the 'charged' level.

The batteries were purchased in early April from Battery Source, and are supposedly private labeled by Superlex. All indications are the batteries were fresh. I was told that the batteries are 225 Ahr, but there is no label that actually says that.

I'm looking at the Iota DLS-30. I understand roughly what the IQ4 is supposed to do, but I'm not going to be float charging these batteries over a long period of time. Some of the literature at the Iota site appears to contradictory. Will a DLS-30 (without the IQ4 option) put out 14.2 or 14.8 for bulk ? From what I've read, I am left with the impression that 14.8 only exists with the IQ4 installed, and that the jumper switches between 13.6 and 14.2. Is that correct, or is the webpage a bit off ?

The two radios I'm using have a combined load of 450-500 mA (at idle) and somewhere up around 750 mA when moving data. Thus far (even with the wimpy charger I'm using) the batteries have been able to supply that for 10-11 days, with a 16-hours on, 8 hours off, daily cycle. When I see the battery voltage getting down around 12.0V, I pull them for an overnight charge.

Thanks in advance !

BB. · July 2014

Re: Iota Engineering IQ4 option

The Iota have a 10 turn pot you can adjust the set point voltage up or down (I believe you have to pop the cover off the Iota to access the pot).

If your Iota is connected to grid power--Then the IQ4 should do an OK job of keep the batteries charged (possibly adjusting the set point up or down to fine tune).

If the Iota is only used for backup behind a genset--The IQ4 is probably not going to be much help. You want the Iota to output "high voltage" until the battery is 80-90+% charged, then shut down the genset (to save fuel).

-Bill

cosmicray · July 2014

Re: Iota Engineering IQ4 option

I guess my take-away is that the DLS-30 (and probably all the various current models) can supply all three voltages. The IQ4 just fiddles with a resistor stack, that controls what the switching supply is putting out. But the IQ4 does it intelligently, w/r/t to specific intervals and voltages observed.

The DLS-30 I'm going to order will be on the grid, but the batteries will be connected to it infrequently. Hopefully no more than twice a month. As I'm not going to be continuous float charging, the IQ4 sounds like an option that would be of less value to me.

Still open to other opinions tho.

BB. · July 2014

Re: Iota Engineering IQ4 option

The IQ4 spec sheet:

http://www.iotaengineering.com/iq.htm

-Bill

Plowman · July 2014

Re: Iota Engineering IQ4 option

I have an Iota DLS-45 which I use to charge batteries using a generator. It has a detachable IQ4 unit.

It works as advertised, but main problem with it is the voltage is too low for absorption stage, at least for Trojan batteries. I opened it up and turned the potentiometer to get it to 14.8V, which is what Trojan recommends. Default is 14.2V for some reason. Now I've changed the settings, the IQ4 feature is no longer useful, voltages are all wrong.

The units without the IQ4 feature just have a phone-type plug that you plug into a socket to increase the voltage. This allows you to switch from 13.6V to 14.2V.

I use mine to bulk charge with a generator in bad solar conditions. So keeping it at 14.8V is sufficient for my application. I'll keep the IQ4 doodad around in case I ever need to charge my batteries from grid power.

The Iota can also be used as a 12V converter. I tested mine recently, drew ~8.5W @ 120VAC with no load. Worked fine as a converter.

Plowman · July 2014

Re: Iota Engineering IQ4 option

BB. wrote: »

If the Iota is only used for backup behind a genset--The IQ4 is probably not going to be much help. You want the Iota to output "high voltage" until the battery is 80-90+% charged, then shut down the genset (to save fuel).

-Bill

Bill, it just occurred to me that maybe I should tune the voltage to 14.8V when the dual voltage jack is plugged in. If I unplug it, it should reduce the voltage to 14.2V.

Wouldn't the lower voltage be better for bulk charging? Lower volts = higher amps going into a discharged battery?

BB. · July 2014

Re: Iota Engineering IQ4 option

Battery below 14.2 volts--Either will give you the same charging amperage into the battery bank (should be the rated capacity of the charger).

When the battery reaches at 14.2 volts--The lower set point will hold that voltage and the battery current will taper down.

Or, set the voltage to 14.8 volts, the battery will continue the high current charging until it reaches 14.8 volts, then taper down.

Using made up numbers, you would get maximum current from 14.2 to 14.8 volts or roughly from 80% to 90% state of charge--basically, getting more AH into the battery bank with a minimum of generator run time--And potentially, saving some fuel too (running generator over 50% of rated load and more fuel efficient).

Of course, running higher current at higher voltage, the battery bank will tend to run hotter at the end of the charging cycle. As long as you monitor the temperature of the battery bank and don't let it get too hot--Should not be a problem with the higher charging current.

-Bill

cosmicray · July 2014

Re: Iota Engineering IQ4 option

Plowman wrote: »

The units without the IQ4 feature just have a phone-type plug that you plug into a socket to increase the voltage. This allows you to switch from 13.6V to 14.2V.

Right, but plugging in the external IQ4 (in place of the jumper) is documented to produce 14.8V during the initial charge phase. So getting the higher voltage is possible without opening the unit and fiddling with the 10 turn pot.

I have a DLS-30 on order. After it arrives, and I have a chance to do a proper battery charge, I may do some poking around to learn how this works. My hunch is that the 14.8V is reserved for the IQ4, so as to prevent someone turning it up, forgetting it's at the higher voltage, then damaging the batteries ("idiot proofing" to use a technical term).

Plowman · July 2014

Re: Iota Engineering IQ4 option

cosmicray wrote: »

Right, but plugging in the external IQ4 (in place of the jumper) is documented to produce 14.8V during the initial charge phase. So getting the higher voltage is possible without opening the unit and fiddling with the 10 turn pot.

I don't think so. If you look at Iota's site, 14.2V is the maximum set point for the IQ4. I don't recall ever seeing 14.8V when I was using the IQ4.

ETA: 14.2V is for absorption. Their site does claim 14.8V for bulk, but like I said, I don't recall seeing this. Trojans should be at 14.8V for absorption.

Blackcherry04 · July 2014

Re: Iota Engineering IQ4 option

Plowman wrote: »

ETA: 14.2V is for absorption. Their site does claim 14.8V for bulk, but like I said, I don't recall seeing this. Trojans should be at 14.8V for absorption.

The 14.2v is held for 8 hours with the IQ4. There 3 variables in charging, Time, Voltage and Current, one can be changed and it effects the other. 14.2v Absorption, it can give the the same result as 14.8v for 2 hours. The bottom line would be , how do the SG's look at the end of the Absorb time.

To say " Trojans " is probably 10 different batteries with different plate construction, some may need 14.8v and some may not. T-105's are usually happy with 14.4v to 14.6v temperature corrected with a 1-2 hr absorb. The " RE " version may be different.

.

PNjunction · July 2014

Re: Iota Engineering IQ4 option

Re - the Trojan AGM specs and IQ4 -

The specs assume one is using a bog-standard CC/CV charger, but not one using pwm for the CV regulation. The Iota may be using pwm techniques in absorb, which Morningstar said years ago was much more efficient than a standard CV. Perhaps this is the reasoning for their slight lowering of voltage in absorb. Bulk takes it to 14.8 in CC, but I'm assuming pwm or some other sort of waveform for the Iota in 14.2v CV absorb. Has anyone put a scope on an Iota?

Maybe your Trojans would do just fine with the default setup this way.

cosmicray · July 2014

Re: Iota Engineering IQ4 option

PNjunction wrote: »

Re - the Trojan AGM specs and IQ4 -

The specs assume one is using a bog-standard CC/CV charger, but not one using pwm for the CV regulation. The Iota may be using pwm techniques in absorb, which Morningstar said years ago was much more efficient than a standard CV. Perhaps this is the reasoning for their slight lowering of voltage in absorb. Bulk takes it to 14.8 in CC, but I'm assuming pwm or some other sort of waveform for the Iota in 14.2v CV absorb. Has anyone put a scope on an Iota?

I've seen nothing in the Iota docs that mentions pwm. In fact, since you can run multiple Iota charges in parallel (to achieve higher current levels), by using the special IQ4 parallel cable, I would expect they are putting out pure DC current. The only way they could run parallel in pwm, would be for the IQ4 to be synching the outputs (possible, but tricky).

cosmicray · July 2014

Re: Iota Engineering IQ4 option

After doing much reading & researching, I find that there are two approaches to equalization. One method involves equalization before float (probably on every charge cycle) and the other involves periodic equalization (which is what the IQ4 does). My impression is that these two approaches are also related to the expected physical arrangement of the charger/batteries.

Iota's IQ4 approach seems to expect that the charger and batteries are stationary, and continuously connected ...

If the battery has remained in the Float State for seven days, the IQ4 automatically provides an equalization charge to dissolve any sulfate layer on the battery’s plates and to avoid stratification.

The other approach, where the batteries are a portable store of energy and not continuously connected to the charger (my situation), is probably more like the image depicted over at batterytender's FAQ ...

Is there any harm in doing it that way, where equalization happens after Absorption and before Float ?

The other bit of information about the IQ4 is, during Bulk, it appears to disable voltage regulation and let maximum current flow, until a trigger voltage is hit. This, more or less, agrees with the diagram from battery tender.

BB. · July 2014

Re: Iota Engineering IQ4 option

cosmicray wrote: »

Is there any harm in doing it that way, where equalization happens after Absorption and before Float ?

The "end" of the absorb phase goes to float. So, going to Equalization should not be an issue... Unless the batteries are already quite warm/hot--That would be my only concern.

The other bit of information about the IQ4 is, during Bulk, it appears to disable voltage regulation and let maximum current flow, until a trigger voltage is hit. This, more or less, agrees with the diagram from battery tender.

Bulk, as I understand, is simply the maximum output current of the battery charger until the battery voltage reaches the Absorb set point, then the currently slowly drops as the battery accepts less current (as it becomes more full).

That Bulk/Absorb transition point is going to vary based on battery state of charge, temperature, maximum "bulk" charging current and such.

A few chargers will have a higher bulk voltage set point and once that voltage is reached, then will "fall back" to the absorb voltage regulation set point.

I think this is sort of "fuzzy" rather than absolute--And is close enough for government work in standard applications.

Some of these algorithms are probably weighted towards the quickest charging time to get quickly back into service for the next shift (forklift/traction batteries).

"We" here would be more limited by what the sun can provide and limitations of generator run-time/fuel usage (for off grid applications).

-Bill

Cariboocoot · July 2014

Re: Iota Engineering IQ4 option

The term "Equalization" is perhaps incorrectly applied here in respects to RE systems. EQ is done to bring the SG of all cells in line. It is not normally done on every charge cycle, nor is it normally done on AGM batteries (the SG of which can not easily be determined).

What you're looking at in that "adaptive 4 step AGM charging algorithm" is the sort of profile typically associated with AC power chargers. The stages could be described as: Bulk, maximum current (with limit) over Time until Absorb Voltage reached; Absorb, fixed Voltage with declining current over 1.5Time; Equalize, constant current at slightly elevated Absorb Voltage (with limit) for 0.5Time; Float, constant lower-than-Absorb Voltage with current demand varying against load over indefinite time.

This is the normal way these batteries would be charged in an industrial application (such as a floor scrubber or motive force use).

The Iota IQ4 function does indeed expect to be connected continuously and will activate its Equalization mode at intervals designed to keep the battery from failing. It is in essence an adapted RV power Converter.

Neither of these match the profile derived from solar, but any one of the three will work for keeping the batteries charged. Keep in mind that the standard application for these type batteries is "draw down, charge up". Not "draw down overnight with varying charging/discharging during the day which ends up (we hope) being recharging overall".

Solar applications are rough on batteries.

vtmaps · July 2014

Re: Iota Engineering IQ4 option

cosmicray wrote: »

After doing much reading & researching, I find that there are two approaches to equalization. One method involves equalization before float (probably on every charge cycle) and the other involves periodic equalization (which is what the IQ4 does).

One thing to note: the mandatory EQ that Iota does every week while on long term float is not really an EQ... or not in the usual RE sense. The Iota EQ is really just a bulk/absorb cycle with the same set points as its regular bulk and absorb.

Iota's (and several other battery charger manufacturers) rationale for doing this is that long term float leads to stratification of the electrolyte and a periodic bulk/absorb cycle will stir up the electrolyte. Obviously, since the battery is on float and, nominally, fully charged, the bulk is extremely short and the absorb not too long either. It basically holds the battery above gassing voltage for awhile.

Whether a battery in float actually does become stratified is, at least in my mind, an unsettled issue.

--vtMaps

PNjunction · July 2014

Re: Iota Engineering IQ4 option

Cariboocoot wrote: »

This is the normal way these batteries would be charged in an industrial application (such as a floor scrubber or motive force use).

That chart above is intended for that - 14.9v absorb! With an "eq" reminescent somewhat of an IUIa algorithm. Meant for fast turnaround of forklift shifts etc so you nailed that right away. You won't find this in those 1.25a battery tenders.

cosmicray · July 2014

Re: Iota Engineering IQ4 option

The DLS-30 came in yesterday. It checked out a little bit below the spec'ed voltages. After trading a few emails with Iota, they told me to adjust it up (my idea, saves time and packages flying cross country).

The external jack on the back is a 4P4C (sometimes called an RJ9). This is the same as what has been used on wireline telephones, between the handset and the desktop unit.

cosmicray · July 2014

Re: Iota Engineering IQ4 option

Started a charge about an hour ago. Within 30 seconds, the fans on the back of the DLS-30 kicked in.

At 15 minutes, the wires (10-ga primary) were barely warm to the touch. The voltage stabilized fairly quickly to 13.62. That, times 30 amps, comes out real close to the rated power of the unit (400 watts continuous). I'm guessing when I see the voltage begin to creep towards 14.2, that tells me that the current flow is subsiding.

My only question tho, is how much of the 400 watts is being put into the cells, and how much may be out-gassing as heat. I'm going to watch this for 3 or 4 hours, then I may drop the voltage back to 13.6 for overnight.

vtmaps · July 2014

Re: Iota Engineering IQ4 option

cosmicray wrote: »

My only question tho, is how much of the 400 watts is being put into the cells, and how much may be out-gassing as heat.

Out-gassing as heat? Gassing and heat production are separate processes. When charging a flooded lead acid battery, the two most important ways that energy is lost are:
resistive heat loss (I²R losses) and electrolysis of water into hydrogen and oxygen. Electrolysis only occurs late in bulk and throughout absorb. Resistive losses depend on both the voltage and internal resistance of the battery, and vary during the charge cycles.

Generally, bulk charging is very efficient, and absorb is progressively less efficient. Float is zero efficiency, because you are putting energy in and the SOC is not rising.

--vtMaps

cosmicray · July 2014

Re: Iota Engineering IQ4 option

Completed my first charge cycle, 4 hours in Bulk (14.2V) and 6 hours at 13.6V. Towards the end of the Bulk I could hear some pronounced belching sounds in the cells (maybe once or twice a minute). Voltage at the switch-over was 14.1, then dropped to 13.6 when I pulled the little plug. Thru most of this I was dealing with thunderstorms moving by, but no power interruptions that I'm aware of. After the batteries rest for a few hours, I want to see if the SG has come up to something more indicative of charged cells.

inetdog · July 2014

Re: Iota Engineering IQ4 option

vtmaps wrote: »

Generally, bulk charging is very efficient, and absorb is progressively less efficient. Float is zero efficiency, because you are putting energy in and the SOC is not rising.

--vtMaps

True float, as in maintenance, is zero efficiency, but the set points of most three stage chargers are such that some charging and SOC increase will happen during Float, just not as much as the batteries may need at that time.

Cariboocoot · July 2014

Re: Iota Engineering IQ4 option

Define "efficiency".
Preventing a decline in SOC is the purpose of the float charge.
When dealing with batteries the ol' water analogy doesn't hold up - unless there's a hole in your bucket.

cosmicray · July 2014

Re: Iota Engineering IQ4 option

Back to (one of) the original topics of this thread, namely how the IQ4 tells the power supply to put out 14.9V

I did a little snooping around yesterday. As I only have a DVM, and no O-scope, was kinda limited in what I could learn.

The 4p4c jack on the back of the case has 4 possible connections. On my unit, only three were connected. I'm going to number them from the far side of the fan (1) to nearest to the fan (4).

1 - black wire
2 - red wire
3 - green wire
4 - n/c (possibly intended for yellow on certain models)

The wires are sent to a header connecter on the main PCB. The various pins are marked: RED, GRN, BLK, YEL. The last is not connected to a wire.

BLK appears to be reference ground.

RED appears to be the current positive output voltage (nominally 13.6V)

GRN appears to be a control line. When the plug is inserted, GRN is shorted to ground, and the output voltage goes up to 14.2V. GRN, when not shorted, floats at 2.2V-2.3V. Not having an O-scope, I could not tell if that is DC or a PWM waveform.

The IQ4 is monitoring RED (and likely using it as a supply voltage to drive a chip). The voltage on RED tells it when to change from bulk to absorption (based on crossing a trigger voltage during charge). What is not clear, is how the IQ4 tells the GRN control line to up the voltage to 14.9V for equalization. My only guess is some kind of pull up resistor, but I'm not brave enough to try it at this time.

BTW, the default jumper plug shorts 1-to-3, and 2-to-4. Since there is no wire on 4, only the 1-to-3 wire does anything.

My guess is that a DLS series unit with internal IQ4, is really the same unit with a small PCB mounted on the header connector instead of wires.

cosmicray · July 2014

Re: Iota Engineering IQ4 option

After a second full charge using the DLS-30, I now see specific gravity of 1.265 - 1.275 across all the cells. While using the DLS-30 instead of my old 10-amp generic charger does not seem to be getting me any longer discharge times, it has improved the SG, which I assume is a good thing for the long term health of the cells. This time I did 5.5 hours at 14.2V, then 8 hours at 13.6. Seems to be a good combo.

The one question I have is about about the AH rating on the batteries. They have a 225 AH rating, and I'm only drawing them down to the 50% level (about 12V across all 6 cells). Is that a pure conversion that I'm using 113 AH ? If so, that works out very close to my average estimated current draw of 0.75A at ~150 hours, to get to 50%.

Cariboocoot · July 2014

Re: Iota Engineering IQ4 option

cosmicray wrote: »

The one question I have is about about the AH rating on the batteries. They have a 225 AH rating, and I'm only drawing them down to the 50% level (about 12V across all 6 cells). Is that a pure conversion that I'm using 113 AH ? If so, that works out very close to my average estimated current draw of 0.75A at ~150 hours, to get to 50%.

If only it were that simple.
The 225 Amp hour rating is based on controlled conditions, including steady-current discharge, over 20 hours.
At any given moment the actual capacity of the battery changes depending on the rate of discharge: higher rate = lower capacity (hence the various ratings on batteries for 8 hours, 15 hours, etc).
So an SG reading that indicates 50% SOC means there is 50% of the capacity of the 20 hour rate left, more or less. Even a change in temperature will affect it. Although your discharge rate may average 'X' the varying current will change the capacity unevenly over time. In other words average 'X' Amps over 'Y' hours does not necessarily equate to 'XY' Amp hours used.

But it's close enough for government work.

cosmicray · January 2015

Re: Iota Engineering IQ4 option

cosmicray wrote: »

What is not clear, is how the IQ4 tells the GRN control line to up the voltage to 14.9V for equalization. My only guess is some kind of pull up resistor, but I'm not brave enough to try it at this time.

After 5-6 months of wondering about this, I now have the answer. You bias the third wire negative to kick up to the higher voltage. This was observed on my new O-scope, and for lack of a decent negative off of ground voltage source, I used 2 AA batteries with the positive to ground, and the negative to the control line. The output voltage from the DLS-30 immediately jumped up to 14.9-15.0.

A crafty design choice. Anyone with a battery holder, a couple of cells, a 4P4C connector and a length of the correct wire can do this (without fiddling with the internal 10-turn pot). No clue how long the batteries would last, but I am now on the road to a more permanent solution.

lbzya · March 2016

Any more progress into making an adapter to get the voltages up?

Mountain Don · March 2016

AFAIK, turn the "pot" that is hidden inside to increase the voltage output. That's what I have done on an iota I have. It is only used with generator power so that works well enough for my purposes.

Iota Engineering IQ4 option

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