Charger Draw When Operating on 20amp Shore Power?

[RickO]

We're currently set up at my father in law's little farm in Minnesota and hooked up to a 20amp circuit in his barn. I'm actually quite impressed with performance of my EMS in these conditions. It's been hot and humid so naturally the AC is the big current draw but the EMS has managed it well... running only the first stage of my basement air but it's kept us reasonably comfortable so far.

We're being careful not to use unnecessary appliances, etc and trying to keep the steady state draw at or below 18 amps. So far so good.

My question concerns the battery charger built in to my Dimensions inverter. I always keep it set to limit current to 5 amps to avoid cooking my batteries.... again... but that's another story. Does the charger pose a threat to tripping a 20 amp breaker if it were to come on and begin a charge cycle? Should I manually turn off the charger from the Dimensions control panel to avoid this and then turn it back on before we travel?

It seems I take two steps forward and one step back with my understand of how this stuff works... but I'm getting there!

[Harry B]

What the 5 amp setting on the Dimensions unit means is that the maximum AC it allows it to draw is 5 amps. This would most likely occur only during bulk charge mode. If you don't draw out more than about 15 amps DC the charger can keep up with the demand set at the 5 amp AC limit. When the charger stays is in float mode it uses less that 1 amp.

If for some reason it goes into bulk charge mode and you are already drawing 15+ amps it may trip the breaker in the house.

[wa8yxm]

The charger's power draw is dependent on two things.. ONE is the current charge rate. You have that set to five amps and that translates to "less than 1 amp" at the 120 volt side (Even allowing for conversion loss and overhead)

Also the load... Question about your Dimensions charger.. from what you say (You can set the charge rate) Is this a 3 stage charger

5 amps... I have a luggable "Jump start" battery.. 5 amps would be about the right charge rate for it.

You can go up to 30% of the battery's amp hour capacity if you have a smart charger in bulk mode.

If that is a single stage converter... You should consider an upgrade.

NOTE: on this rig the converters (Plural 2 independent house battery systems) can draw 20 amps easy between them. IF THE BATTERIES ARE IN BULK MODE.

In Absorption or float.. The current drops way way way way down.

[RickO]

Quote:

Originally Posted by wa8yxm The charger's power draw is dependent on two things.. ONE is the current charge rate. You have that set to five amps and that translates to "less than 1 amp" at the 120 volt side (Even allowing for conversion loss and overhead) Also the load... Question about your Dimensions charger.. from what you say (You can set the charge rate) Is this a 3 stage charger 5 amps... I have a luggable "Jump start" battery.. 5 amps would be about the right charge rate for it. You can go up to 30% of the battery's amp hour capacity if you have a smart charger in bulk mode. If that is a single stage converter... You should consider an upgrade. NOTE: on this rig the converters (Plural 2 independent house battery systems) can draw 20 amps easy between them. IF THE BATTERIES ARE IN BULK MODE. In Absorption or float.. The current drops way way way way down.

Thanks much! Yes, my Dimensions has a three stage charger and a button on the control panel labled "Charger Draw... Set Limit". That is where I set the 5 amp limit. New, it came from my dealer with the limit set to 25 amps and I cooked two sets of house batteries before the dealer called Dimensions and was told to set it at 5 amps.

My concern, being limited to 20 amps shore power right now, is that the charger might kick into bulk mode and cause the shore 20amp breaker to trip. If that's a valid concern, should I just turn off the charger until shortly before I plan to travel? Maybe I'll just wait and see if the breaker trips for an unexplained reason and turn it off when and if that happens. Interesting stuff.

[1ciderdog]

Not an answer to your question but a statement and two questions. The statement is a three stage charger should not cook batteries. My understanding is a three stage charger it should bring the batteries up to full charge and then trickle charge to maintain charge. The questions would be do you regularly check the water level in the batteries and have you considered the possibility the three stage charge may be defective?

All that said with my previous couch I've spent many a day at my daughters on a 20 amp circuit running the A/C almost 24 hours a day and have had no problem running the A/C - no circuit breaks, no problem with battery charging, etc. I did not use the 120 volt for hot water heating or much of anything else except TV.

[RickO]

Quote:

Originally Posted by 1ciderdog Not an answer to your question but a statement and two questions. The statement is a three stage charger should not cook batteries. My understanding is a three stage charger it should bring the batteries up to full charge and then trickle charge to maintain charge. The questions would be do you regularly check the water level in the batteries and have you considered the possibility the three stage charge may be defective? All that said with my previous couch I've spent many a day at my daughters on a 20 amp circuit running the A/C almost 24 hours a day and have had no problem running the A/C - no circuit breaks, no problem with battery charging, etc. I did not use the 120 volt for hot water heating or much of anything else except TV.

Hi Bob. I certainly agree with your statement. My three stage charger shouldn't cook the batteries. How frequently I checked the water is a fair question. I didn't do it weekly but inside of just a couple of months two sets of new batteries were cooked. I had assumed that the charger was defective but the dealer couldn't find anything wrong with it and called Dimensions. That's where they learned that the charge current had to be limited to 5 amps instead of the 25 it came set at.

If you browse this and other forums I think you'll find this inverter/charger is the butt of a great many jokes. It has apparently earned quite a reputation.

We're still doing ok on the 20 amp shore power here. My post is really aimed at getting a better understanding of how my equipment is supposed to work and what I should expect. My basement air is a two stage unit. First stage draws 14 amps and the second draws an additional 10. The EMS is doing a pretty good job of managing things but I have the water heater and fridge both on LP power to releave some of the load.

[Gary RVRoamer]

You've said two different things about the current limit. Once you called it charger draw limit and elsewhere you called it a charge current limit. Those are two different things. A 5A limit on input still allows about 50 amps of charger output. That will still cook batteries if indiscriminately applied. A 5A charge output current limit, however, is only a notch above a trickle (float) charge. In any case, a charger that won't manage the charge rate properly is a worthless piece of jun, IMO.

For what it's worth, I hear a lot of complaints from Winnie owners about their Dimensions brand chargers, so you probably aren't alone. Maybe call Winnie Customer Service and ask?

[RickO]

Quote:

Originally Posted by RV Roamer [Gary] You've said two different things about the current limit. Once you called it charger draw limit and elsewhere you called it a charge current limit. Those are two different things. A 5A limit on input still allows about 50 amps of charger output. That will still cook batteries if indiscriminately applied. A 5A charge output current limit, however, is only a notch above a trickle (float) charge. In any case, a charger that won't manage the charge rate properly is a worthless piece of jun, IMO. For what it's worth, I hear a lot of complaints from Winnie owners about their Dimensions brand chargers, so you probably aren't alone. Maybe call Winnie Customer Service and ask?

Sorry for the confusion Gary. The button on my Dimensions reads "Charger Draw.. Set Limit". I too have heard a LOT of complaints about the Dimensions chargers and am pretty convinced they are a piece of junk but since I learned to limit the charger draw to 5 amps it has been at least doing an acceptable job so maybe someday I can replace it with a pure sine wave inverter unit but it hasn't worked up to the top of the priority list yet.