Iota charger

[SDC]

Well, I finally ordered a standard Iota DLS-55. The powermax was interesting (and nicely priced) but I just couldn't find one at reasonable shipping costs...

Thank you all

[Sunking]

The Iota I have, is a simple DC supply. No smarts in it other than a trimpot. The IQ plg they sell,

That's the RJ-46 Jack right? That is what I recall. Reading the manual, they are not claiming 4-stage exactly. With the simple wire jumper it goes up 1 volt from Float. Use the IQ plug and I assume it does a pseudo 3-stage from the description of a higher voltage Bulk Absorb stage. Not real clear. Me thinks it just jacks up the voltage to a EQ level. Only difference between a Float Charge and EQ Charge is the voltage.

[PNjunction]

I looked at the Samlex chargers and their lititure states they have to charge with no load on the batteries. I am confused here and obviously missed something.

The reason for that is that with a load active, and you have the absorb setpoint at 14.4v, if the load is small enough, the batteries will eventually reach absorb, but never come out, as the load prevents the charger from seeing a falling current and triggering the switch to float. - so one could end up in an endless-absorb state. And that is if your gear can handle 14.4v.

What they recommend if you do that, is to use the 13.6v setting, which of course means that the battery should no longer be used in a cyclic-service, but one of standby. In this setting, yes you could run with a load easily, but you give up cycle-service from the battery.

[Mike90250]

The Iota I have, is a simple DC supply. No smarts in it other than a trimpot. The IQ plg they sell, just modulates the output voltage, but I don't see how they can call it 4 stages (or even 2 w/o the IQ).

A pair of computer PSU units geared to 12V, would be better, the new ones have PF correction.
600w : +3.3V@22A, +5V@18A, +12V1@23A, +12V2@20A, -12V@0.3A, +5VSB@2.5A Thermaltake TR2 TR-600 600W

= 40A @ 12.01V, if you can fool the other voltages into staying in regulation. $50 US.

[Sunking]

Yes, I have the DLS-30 with built in IQ4 which they say makes it a true 4 stage charger (Bulk =2.466V per cell; Absorb= 2.366V per Cell; Float= 2.266V per cell). As for what the charger pushes to my battery, your explanation is what I thought was happening, thank you for the clarification.

NP you are welcome.

[mschulz]

First what model are you talking about?

Two Stages. They have a IQ-4 option that plugs into the same port as the other 2-stage plug, but gives you 3 or 4 stages. Perhaps they have changed the design to make it a True 4-stage charger.


As for current, that depends on two factors: How much current the charger is capable of supplying, and the state of charge the battery is in with respect to the battery internal resistance. So th eIota model you are talking about has a limit of 30 amps. If you connect it to a discharge battery say 12.4 volts, and the charger is set for 13.6 volts, it will supply 30 amps until the battery voltage approaches 13.6 volts. At that point the current will begin to taper off toward 0 amps. When the current tapers off to roughly 3% of C, the battery is charged up.

Yes, I have the DLS-30 with built in IQ4 which they say makes it a true 4 stage charger (Bulk =2.466V per cell; Absorb= 2.366V per Cell; Float= 2.266V per cell). As for what the charger pushes to my battery, your explanation is what I thought was happening, thank you for the clarification.

[Sunking]

Sunking, I think I have missed some lessons here and I hope you will help me catch up. With the IOTA, everything I read says it is a four stage charger. When they say it is a 30 amp converter / battery charger am I getting the full 30 amps to my battery. If not, the IOTA is useless to me except a way to convert my AC generator power to DC power.

First what model are you talking about?

The Iota DLS i snot what I would call a battery charger, its a regulated DC power supply which can be used as a battery charger. There is a very fine line between a battery charger and DC power supply. The difference lies in output filter capacitors to clean up the rectifiers. A DC supply will have good filtering giving you a nice clean steady state DC voltage that you can use to power Gizmos directly from and charge a battery if you want.

For Iota its been a while but I have experience with the DLS series. The DLS is really a DC power supply that you can set the output voltage and have two options to convert to a charger. One is a plug and all it does is raise the voltage up from a Float Voltage of 13.6 volts to 14.something or Two Stages. They have a IQ-4 option that plugs into the same port as the other 2-stage plug, but gives you 3 or 4 stages. Perhaps they have changed the design to make it a True 4-stage charger.

As for current, that depends on two factors: How much current the charger is capable of supplying, and the state of charge the battery is in with respect to the battery internal resistance. So th eIota model you are talking about has a limit of 30 amps. If you connect it to a discharge battery say 12.4 volts, and the charger is set for 13.6 volts, it will supply 30 amps until the battery voltage approaches 13.6 volts. At that point the current will begin to taper off toward 0 amps. When the current tapers off to roughly 3% of C, the battery is charged up.

[mschulz]

Yest that is what I am talking about but that is a moot point because you are going to open the unit up and adjust to correct voltage and never use the jack to begin with. With the Iota you have a uni-tasker and can only do one thing either a quick charge or EQ charge. To get a multi-tasker will require mo money and for off-grid is unnecessary.

Sunking, I think I have missed some lessons here and I hope you will help me catch up. With the IOTA, everything I read says it is a four stage charger. When they say it is a 30 amp converter / battery charger am I getting the full 30 amps to my battery. If not, the IOTA is useless to me except a way to convert my AC generator power to DC power.

I looked at the Samlex chargers and their lititure states they have to charge with no load on the batteries. I am confused here and obviously missed something.

[mapmaker]

For me the point is to make the fuel cost as little as possible. I usually advise folks to get a smaller generator, and have a longer run time to charge the batteries.

You want your charger to load the genny to about 75% capacity to get maximum efficiency from your fuel burn. Second thing is if you do not get at least a C/12 to C/10 charge rate EQ will either take forever, or never get there.

Some generators are most efficient at closer to 100% of their continuous ratings. In my preceding post, just define "fully loaded" to mean "loaded to peak efficiency". It will be different for every generator.

As for needing a C/12 rate of recharge... you are correct that at least one battery manufacturer recommends a C/10 rate, but most do not. It's quite possible to charge many FLA batteries with a C/20 rate. I agree that it might take a long time.

My point is that there is at least a 100% range in acceptable charging currents. In some systems (where charging is the major generator load) that means there is a 100% range in acceptable generator sizes. In many circumstances (but not all) I recommend that folks avoid the high end of the generator size range. A smaller generator means less investment in generator, and may mean lower fuel costs.

--mapmaker

[Sunking]

Correct me if I'm wrong Sunking you are talking about what Iota names a dual voltage jack. Right? According to their documentation, that allows the user to select output voltage of 13,6V or 14,2V. As other mentioned, 14,2 is nowhere near EQ voltage for FLA..

Yest that is what I am talking about but that is a moot point because you are going to open the unit up and adjust to correct voltage and never use the jack to begin with. With the Iota you have a uni-tasker and can only do one thing either a quick charge or EQ charge. To get a multi-tasker will require mo money and for off-grid is unnecessary.

[Sunking]

For me the point is to make the fuel cost as little as possible. I usually advise folks to get a smaller generator, and have a longer run time to charge the batteries.

Then you are over looking something then. You want your charger to load the genny to about 75% capacity to get maximum efficiency from your fuel burn. Second thing is if you do not get at least a C/12 to C/10 charge rate EQ will either take forever, or never get there.

[inetdog]

... most full featured inverter/chargers will cut back the charging current so as not to overload the generator.

And there is the rub, as a simple charger-only unit will have no idea of your other loads.

[mapmaker]

Point is when you are running a genny, you want to make the run time as short as possible and the only way to do that is to charge with as much current as you can within limits.

For me the point is to make the fuel cost as little as possible. I usually advise folks to get a smaller generator, and have a longer run time to charge the batteries.

The reason is that most generators are more efficient when they are fully loaded, and a smaller generator is easier to keep fully loaded than a large generator. The smaller generator will have to run longer to charge the batteries, but it may use less fuel to deliver the kwh needed to charge the battery.

If there are large AC loads using most of the capacity of the generator, most full featured inverter/chargers will cut back the charging current so as not to overload the generator.

--mapmaker

[SDC]

That is backasswards, no chargers go to EQ after Float, its the other way around where after EQ it switched to Float.

Anyway there are two methods to EQ with the Iota. If you do not opt from for the IQ option, you just plug in the 2-Step into the jack and it raises the voltage from float to about any voltage you want to EQ at. If you get the IQ4 option it will automatically go into EQ is the battery is not used in 7 days, or manually switch it in via software.

Some other manufactures to consider are:

Samlex
Quick Charge
Power Charge

Correct me if I'm wrong Sunking you are talking about what Iota names a dual voltage jack. Right? According to their documentation, that allows the user to select output voltage of 13,6V or 14,2V. As other mentioned, 14,2 is nowhere near EQ voltage for FLA.

Anyways, I've looked at the models you've suggested and as you said, although they look really nice, they are pretty darn expansive (especially the Samlex). With the exception of the Power Max which is actually cheaper than the Iota. Would you suggest going with Power Max instead and if yes, why? (I'm concerned about reliability)

Also, I'm hesitating between the 45A and 55A models (Samlex solved that questions pretty good by making a 50A model but I just don't want to spend the extra money and be obligated to sell the cabin! ) So, 45A brings me to C/10,3 which as acceptable and the 55A model brings me to C/8,4 which is close to the limit... I'm scratching my head now! As you said, I want to run my generator for the shortest possible period of time so I tend to go with the 55 but at the same time, I don't want to mess the batteries... Your opinion on this?

So, if I get it correctly, the IQ4 turns the charger into a real 3 stage charger. Without IQ4, it is just a kind of manual charger (13,6V or 14,2V, selectable) that has some kind of a float function in order to avoid to toast the batteries in case you leave the charger on without attending. Right? So, as far as I will be there when the generator runs (and monitoring the batteries), I don't really need IQ4. Right?

Finally, for those of you who are concerned about the generator loading issue, I have a Honda EU3000is. It has a maximum continuous output of 2800 watts @ 120V (23,3 amps). Iota claims that its 55 amps charger will draw a maximum of 13,4A @ 108V so I honestly really don't see how that could become a concern... That being said, it is a good reason why I'm considering the Power Max model (55A also) as it's manufacturer claims a maximum draw of 7 A (780W) @ 108V. Although the EU3000 can power both chargers, I don't see why I should burn more gas to deliver the same charging output (not mentioning the fact that usually, when the generator runs, I kind of take advantage of it and run as much power tools and other heavy consumers as I can, so having a less hungry charger would leave me extra watts to power other stuff.)

That's about it...for now! Thank you everybody for the answers btw.

[SunEagle]

A charger that pushes 50 amps into a 12 volt battery (at up to 15.5 volts) is 775 watts into the battery. Even if the charger is not very efficient and has a poor power factor, it would be a small load on a 5500 watt generator.

Some of the larger Iotas that charge at less than 1000 watts have been too much load for a number of "2000 watt" generators, including the Honda eu2000.

--mapmaker

You are correct. For some reason I just used the generator output amps (~48) and compared it to the charger amps (50). I should have calculated the charger wattage. Dumb mistake on my part.