Charger for RXV - Float Charge

[JohnnieB]

Originally Posted by lococummins

Does anyone know if Delta-Q chargers float charge? That is what I got with my RXV.

No, the Delta-Q does not go into a float charge mode after the regular charge cycle completes.

Originally Posted by MiltonC

The RXV Electric Owners Manual State the following for the PowerWise QE charger: "Once a minimum battery voltage of 2 volts per cell (Vpc) is reached, the charger’s output current will change from a full current charge to the trickle rated charging current. The length of charge time will vary by how depleted the batteries are, the input AC voltage, and/or charger ambient temperatures. The charger’s LED will give a SHORT flash if the charge is less than 80% and a LONG flash if the charge is greater than 80%. If the
charger’s LED is a steady GREEN the batteries are fully charged and the charger may be unplugged, although not necessary. The charger may be left plugged in for long periods of time to maintain the batteries charge level".

Johnnie, Do you interpret this to mean that the Powerwise goes into trickle charge mode and it continues until unplugged?

I interpret to mean that the tech-writer that wrote the manual didn't read the engineering notes or the junior engineer that wrote the engineering notes didn't know much about Deep-Cycle Lead-Acid Wet-cell batteries and one or the other, or both, should be replaced with competent individuals. Of course, the problem may be at a higher level.

Either the statement highlighted in red is ludicrous, or if it is true, the design is.

At rest, 2VPC is less than 50% SoC and since most people charge their batteries before they are discharged down to 50% SoC, the charger would never produce its full charge current.

I suspect the charge current stays limited to whatever the max is until the on-charge voltage is about 2.35VPC and then decreases down to a "Trickle" current of about 1A or 2A until the on-charge voltage reaches about 2.46VPC.

I'm also curious why the toggle point between the LED's short flash and long flash is 80%. The on-charge voltage transition point between full current and reduced current for AGM and Gel-Cells is 80% and is 90% for wet cell batteries.

I've have no personal experience with a Powerwise-QE or Delta-Q charger, but from what I've picked up around here, they do not have a battery maintainer mode of any type. In other words, once the LED turns to steady green, the charger no longer puts out any current and WILL NOT automatically initiate a charge when the pack voltage drops below a predetermined level.

To determine if the charger does anything except sit there with the Green LED glowing, leave it connected and measure the pack voltage about 12 hours after the green LED comes on. If it is about 38.2V for a 36V pack or about 50.9V for a 48V pack, it is not putting out anything.

Let us know what you find.

[MiltonC]

I measured the battery pack with the charger unplugged for about 30 minutes after charging for 24 hrs. The pack measured 51.3 v. After another 24 hrs without charging the battery pack measured 51.1v.

Should I measure it after 24 hrs charging with the charger still plugged in?

[JohnnieB]

Originally Posted by MiltonC

1. I measured the battery pack with the charger unplugged for about 30 minutes after charging for 24 hrs. The pack measured 51.3 v.
2. After another 24 hrs without charging the battery pack measured 51.1v.

3. Should I measure it after 24 hrs charging with the charger still plugged in?

1. I believe the charger completely stops when the steady green LED comes on, so this is 24 hours less the time prior to the green LED coming on steady, of rest time.
2. The is an additional 24 hours plus time in #1 above. Probably something ion the neighborhood of 42 hours total rest time since the charger's green LED came on steady.

3. I suspect that you'll read about the same voltage as you did in #1 above, and if you wait an additional 24 hours with it still plugged it, it'll read about the same as #2.

[MiltonC]

OK, I'll test it an see. Might be a day or two as I am installing a converter tomorrow.

[MiltonC]

Solid green light plus another 24 hrs charging the battery pack measures 51.1v. Exactly the same as it did with the charger unplugged for 24 hrs.

No trickle charge or float charge. When the green light comes on, the charger kicks out. Just as the wise and all powerful JohnnieB predicted.

[cgtech]

just because it says it can, don't trust it. also,who will be there to maintain the cell water,the charger?

[MiltonC]

Originally Posted by cgtech

just because it says it can, don't trust it. also,who will be there to maintain the cell water,the charger?

I plan on doing all the maintenance, and wouldn't trust the charger alone. However, it would have been nice if the Powerwise QE had a float charge.