Iota dls-30 question

Re: Iota dls-30 question

BB. wrote: »

The Iota typically has a little jumper/plug... Plug in is "charging" and plug out is "floating".

Sorry Bill, that's a "gotcha".

As I've mentioned, I've been planning to replace the charger in my camper, so I've recently re-reviewed specs on a lot of chargers.

Be default, the Iota is a 2-stage charger that switches between constant current and constant voltage and uses a single voltage set point. It will constant current bulk up to the set point, then switch to constant voltage float to hold the battery at the set point.

The set point is 13.6v by default - the jumper just changes the set point to 14.2v instead.


Here's what I found in the IQ/4 manual:

"OPERATION OF THE IQ4 IN THE 3-STATE MODE

BULK STAGE - During this state, the charger will operate either at Full Current output or Constant Voltage output depending on the discharged state of the battery. A discharged battery will dictate the voltage and force the charger into constant current operation. As the battery charges, the charger transitions to a constant-voltage operation. This BULK STAGE will continue for either 225 minutes or until the battery voltage reaches the “High Trigger” value (whichever occurs first). At this point, the BULK STAGE will operate for another 15 minutes before switching to the ABSORPTION STAGE.

ABSORPTION STAGE - This state is limited to 480 minutes (8 hours) during which the charger will operate either at Full Current output or Constant Voltage output depending on the discharged state of the battery. During Full Current output, the charger is providing its full current rating and will slowly increase the battery voltage to the “Absorption Stage” voltage. At the end of the 480 minutes, the charger will revert to the FLOAT STAGE.

FLOAT STAGE - This charge state holds the batteries at Constant Voltage for a period not longer than seven days. During this state, the charger not only floats the batteries, but it can also provide load current up its maximum rating for other loads without depleting the battery capacity. The FLOAT STAGE will end when either the battery voltage drops below the “Low Trigger”point or at the end of seven days when the IQ4 initiates an equalization stage to remove sulfate layers from the battery plates. In either situation, the unit exits the FLOAT STAGE and enters the BULK STAGE."


As Bill said, the "EQ" with the IQ/4 is not what would normally be considered an "equalization" (timed overcharge). All it does, is after 7 days at float, it'll do a quick run through of the bulk and absorb stages to keep the battery fully topped off before it drops to float for another 7 days.



To the OP:

The Iota will bulk charge the battery up to 13.6v and then float it indefinitely at that voltage without the jumper or the IQ/4 module. If you need 14.2v instead (perhaps to overcome voltage drop in the wiring), you can can use the jumper.

2-stage is often recommended for charging when there are also loads running from the battery. 3-stage is often recommended if there are no loads running while charging the battery.

The reason is that on some 3-stage chargers, the absorption mode continues until the flow of current drops below say 1a. If there is a load of more than 1a, then the flow of current never does drop, and the charger gets fooled into staying in absorption mode and ends up overcharging the battery.

To get around that problem, some 3-stage chargers set a timer on the absorption stage. They'll drop to float when the timer runs out - even if the current flow never does drop below 1a.

The IQ/4 module does that. It has a timer on the absorption stage. Without the IQ/4 module, the Iota doesn't have an absorption stage, so it's not an issue on a standard 2-stage Iota.

The IQ/4 module also adds extra voltage set points. On a 12v system, it will bulk to 14.8v, absorb at 14.2v, and then float at 13.6v. Without it, there is just the one set point - 13.6v or 14.2v depending if you use the jumper or not.

EDIT: Either way - 2-stage without the IQ/4 or 3-stage with it - it'll float the battery properly without overcharging it.

Re: Iota dls-30 question

I know this thread is dated but for anyone who might happen upon it as I did perhaps I can provide some clarification.
Simple answer to the OP:
If you are plugged into shore power then the IQ4 will be to your advantage.
If however you are hooked to an intermittent power source you many want to give it some more consideration.
The Iota charger is a good compromise and will not over charge your batteries when use properly. This does not mean you can leave the batteries unattended. You will still need to check the electrolyte level on occasion.
Check this thread out for a detail description.
http://forum.solar-electric.com/showthread.php?t=12085
Attached is a graphic that will perhaps help.
The makers of charge controller have a lot of marketing terms that while no untrue can be misleading.
This charge controller and any that I have worked with are always constant current.
The controller delivers all the current it can and the battery will accept. The fact that the current declines is a function of the battery coming up to charge not some function of the charger.
This controller (IQ4) monitors the voltage. When the bulk rate trigger point is hit or the predetermined time is met the controller shifts to the absorption mode.
It remains there for the next 8 hours maintaining the absorption voltage.
Problem for an intermittent power source. The controller does not maintain its memory during a shut down. If power is turned off or lost the Bulk cycle begins again.
Once the 8 hours are up the controller will enter the Float mode again only monitoring and maintaining a float voltage. Until the battery voltage drops below 12.8 or 7 days past.
Here again this may be a problem for an intermittent power source. If the power is off the charger will restart in the bulk mode. Whether or not the battery need charging.
Hope this help

Re: Iota dls-30 question

dwh
Now we are talking about Iota's DLS series chargers correct?
I asked this question directly to Iota's engineering department.

"The absorption mode is purely a timed cycle (8 hours) with a regulated voltage of 14.2 volts?"
The response was,"Yes"

The DLS series controller/chargers are an admiral compromise at an excellent price but they do not have the ability to monitor the charging current.
The DLS is a SMPS (switched mode power supply) That is the reason it is so much smaller, lighter and more efficient that its linear predecessor.
The recommendation from Iota for individual experiencing an interrupted power supply such as operating off a generator was to not use the IQ4 but instead use the manual voltage jack.
Constant voltage/Constant Current
I am not an electrical engineer perhaps someone else within this forum is better equipped to address these terms.

Re: Iota dls-30 question

BB
I didn't think there would ever come a time I would disagree with you. Over the years your advise has helped me a great deal and I am a bit squeamish about belaboring a point. However if I might just clarify a couple of point regarding the DLS chargers.
The standard charger without IQ4 has two voltage setting (jack in - jack out) 14.2 or 13.6 volts. With the addition of the IQ4 controller there is an additional voltage in the bulk stage of 14.6 volts.
If the power is cut the charger will revert back to the bulk stage until the trigger voltage of 14.6 is obtained or 225 minutes have past.
Then it will enter the absorption stage at 14.2 volts for 8 hours (timed period)
Finally it will enter the float stage at 13.6 volts until one of three things happen:
1) 7 days elapse time
2) Voltage drops below 12.8 volts
3) Loss of power which zeros out the memory
When any one of these three thresholds are meet the entire charge cycle start anew. (bulk, absorption, float)
Although the folks at Iota state there is a fourth stage (equalization) there really isn't, it is merely another bulk stage initiated by a timed function as apposed to a trigger voltage.
Now when it comes to the constant voltage/constant current this is the way I understand it.
1) During the bulk charging mode voltage will increase to the cap of 14.8 volts
a. Current will be =< the rated output of the charger (total current is available though not constant)

2) During the absorption mode voltage will be held constant at 14.2 volts (constant voltage)
a. Current will continue to decline

3) During the final float mode voltage is held constant at 13.6 volts (constant voltage)
a.Current flow will be nearly zero if only charging the battery.
b. The power supply is still capable of outputting its full rated output should a load be put on it
c. At this point there is a balance established between the charging voltage and the batteries counter voltage that ≈ 100% SOC

My point BB was that the charger itself has no control circuity to limit the current flow it is the normal relationship between a battery and a charger. Although the sales literature makes it sound like it does.

Finally I'm not knocking Iota. I think the DSL series represents a good compromise and I am the happy owner of one.

It is possible to get a charger with a lot more bells and whistle but at twice the price.