The Iota DLS-90 battery charger specs list a maximum single-cycle inrush current of 40A @ 108V. To what extent do I need to consider the max charger inrush current when choosing the output current capability of the generator that will power the charger? Is a 1/60s brownout going to bring a decent generator (Champion or Honda) to its knees or damage the charger? I haven't seen max inrush current listed for any other brand of battery charger, so is it really an issue at all, or is there something about Iota chargers that makes inrush significant?
Charger Max Inrush Current vs Generator Output Current
- Thread starter Step-Hen
- Start date
luthj
Engineer In Residence
I would not be worried as long as you have some overhead from the nominal output. Remember that most chargers are not power factor corrected, so the rated power consumption needs to be uprated for choosing a generator size. Most chargers will be just fine with a brief power sag upon connection.
restorationrides
Member
In looking at the specs for the DLS-90, it can be seen that it may pull as much as 22 amps continuous. I'm conjecturing then that is when it's at its 90 AMP Peak output voltage DC? The data sheet suggests that it will always charge at the highest initially and then 3-step down from there, so you'll need to allow for that.
How big is your bank of batteries? What size generator do you plan on running?
The rated max 22 cont. amps AC is at the limit of the 2000 series of generators that most people seem to prefer. and that does not even allow for other AC loads running on the generator at the same time.
In addition, the AC peak demand (inrush) is up to 40 amps @108v which, at 4320 Watts, is far beyond the peak amperage rating of any 2000w series generator. It's a very short-lived inrush because it's just charging some capacitors, but that is a very big hit on the generator and might trigger the overload protection cut out. I have had this problem before with an inverter generator even though the inrush current was less than the peak output of the generator.
Anyway, even if you step up to a 3000w series generator, you still won't have much excess capacity to run other devices when your batteries are in deep charging mode on a DLS-90. Maybe you could consider getting a smaller unit, unless your battery bank is big and charge time is very important. Hope that helps...
RestorationRides
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How big is your bank of batteries? What size generator do you plan on running?
The rated max 22 cont. amps AC is at the limit of the 2000 series of generators that most people seem to prefer. and that does not even allow for other AC loads running on the generator at the same time.
In addition, the AC peak demand (inrush) is up to 40 amps @108v which, at 4320 Watts, is far beyond the peak amperage rating of any 2000w series generator. It's a very short-lived inrush because it's just charging some capacitors, but that is a very big hit on the generator and might trigger the overload protection cut out. I have had this problem before with an inverter generator even though the inrush current was less than the peak output of the generator.
Anyway, even if you step up to a 3000w series generator, you still won't have much excess capacity to run other devices when your batteries are in deep charging mode on a DLS-90. Maybe you could consider getting a smaller unit, unless your battery bank is big and charge time is very important. Hope that helps...
RestorationRides
Sent from my REVVLPLUS C3701A using Tapatalk
dwh
Tail-End Charlie
Depends on a few things. That 22a@108v is at 108v - it will be a few less amps at 120v.
Unless you've got a pretty serious battery bank, you are unlikely to ever see 90a to the batteries, thus less than the full rated AC draw.
As to the inrush...
A synchronous generator (standard non-inverter type) won't even blink. The rotating mass won't have time to slow down at all before the inrush is over, and the same with the circuit breaker.
An inverter gen might have a problem as already described, but it just depends on how the control module reacts.
Does the 90a Iota come with a standard wall plug cord? Those are only rated 15a. If it does, I wouldn't worry much about the inrush.
Unless you've got a pretty serious battery bank, you are unlikely to ever see 90a to the batteries, thus less than the full rated AC draw.
As to the inrush...
A synchronous generator (standard non-inverter type) won't even blink. The rotating mass won't have time to slow down at all before the inrush is over, and the same with the circuit breaker.
An inverter gen might have a problem as already described, but it just depends on how the control module reacts.
Does the 90a Iota come with a standard wall plug cord? Those are only rated 15a. If it does, I wouldn't worry much about the inrush.
Thanks, guys. I guess the only way to know for sure how significant the inrush current is is to buy the high-current charger and try it with my genny. This leads me to questions about generator sizing and charger sizing, but I'll post them on a new thread since they are heading off topic...
restorationrides
Member
"Depends on a few things. That 22a@108v is at 108v - it will be a few less amps at 120v."
The generator doesn't see amps it sees power demands (watts). It will likely have a few less amps at a higher voltage BUT that will still be close to the same in power requirements.
"Unless you've got a pretty serious battery bank, you are unlikely to ever see 90a to the batteries, thus less than the full rated AC draw."
All the more reason to select a smaller Iota unit. Why spend the money on a larger piece of equipment that you can't fully utilize...?
"As to the inrush...
A synchronous generator (standard non-inverter type) won't even blink. The rotating mass won't have time to slow down at all before the inrush is over, and the same with the circuit breaker."
I don't think anybody following this blog is seriously considering using an old-school synchronous type generator...
"An inverter gen might have a problem as already described, but it just depends on how the control module reacts."
I can't speak to that. All I know is that it popped the circuit breakers when I tried it on my inverter style generators (2 x 2k in parallel!)
"Does the 90a Iota come with a standard wall plug cord? Those are only rated 15a. If it does, I wouldn't worry much about the inrush."
Yes, it does come with a 15 amp plug. That's a 15 amp continuous rating and does not speak to surge events...
RestorationRides
Sent from my REVVLPLUS C3701A using Tapatalk
The generator doesn't see amps it sees power demands (watts). It will likely have a few less amps at a higher voltage BUT that will still be close to the same in power requirements.
"Unless you've got a pretty serious battery bank, you are unlikely to ever see 90a to the batteries, thus less than the full rated AC draw."
All the more reason to select a smaller Iota unit. Why spend the money on a larger piece of equipment that you can't fully utilize...?
"As to the inrush...
A synchronous generator (standard non-inverter type) won't even blink. The rotating mass won't have time to slow down at all before the inrush is over, and the same with the circuit breaker."
I don't think anybody following this blog is seriously considering using an old-school synchronous type generator...
"An inverter gen might have a problem as already described, but it just depends on how the control module reacts."
I can't speak to that. All I know is that it popped the circuit breakers when I tried it on my inverter style generators (2 x 2k in parallel!)
"Does the 90a Iota come with a standard wall plug cord? Those are only rated 15a. If it does, I wouldn't worry much about the inrush."
Yes, it does come with a 15 amp plug. That's a 15 amp continuous rating and does not speak to surge events...
RestorationRides
Sent from my REVVLPLUS C3701A using Tapatalk
dwh
Tail-End Charlie
You'd be wrong about that. A lot of people on this forum (it's not a blog) have them. I just replaced my old portable gen with a new Champion syncronous. All I use it for is battery charging, so there's no point in overspending to get the job done.
Besides, in terms of watts per gallon, syncronous beats inverter by a big margin.