Forum Discussion

mvas's avatar
mvas
Explorer
Nov 11, 2016

WM EverStart 27DC

I own an 18 month old WM EverStart 27DC battery. The label states, "Manufactured by Johnson Controls". I am looking for the 3-stage charging values for a WM 27DC. I have looked in the WM website and the JCI website, but I have not found any information for a WM 27DC. So, I have been using the values from the US Battery Website for their 27DC XC2.

My assumptions:
80 AH = C 20Hr rating
8 amps ... 10% AH Bulk Charge amps
2 amps ... 3% AH terminates Absorb
2.40 volts x 6 = 14.4 volts ... terminates Bulk Charge
2.55 volts x 6 = 15.3 volts ... terminates Finish Charge
2.17 volts x 6 = 13.0 volts ... Float

#1 Bulk Constant Current = 8 amps until 14.4 volts
#2 Absorb Constant Voltage = 14.4 volts until 2 amps
#3 Finish Constant Current = 2 amps until 15.3 volts
#4 Float Constant Voltage = 13.0 volts forever

Equalization Constant Voltage = 15.3 volts for hour, once per month

I use about 30 Amp-Hours per night.
I recharge the next day.
On average, I use the battery 5 nights per month.
I do not have a hydrometer.
  • I am looking for WM EverStart / JCI 27DC charging values.

    I am currently using the US Battery 27DC XC2 values
    because that is all that I could find.

    I do not think the US 27DC XC2 is the same battery as WM EverStart 27DC.
  • IMHO nothing wrong with those numbers for a rig that does not endure off grid camping longer than a week (more or less). For entended generator camping 14.8 volts should persist until the batteries start bubbling lightly then defeat to float. Your numbers would require a generator to run 9-12 hours to get a full charge.

    Your battery is a hybrid 2-3/4% antimony / calcium negative plate unit. I would limit max discharge to 60% remaining. Drawing deeper causes charge rejection. JC likes power pedestals. The hybrid demands a higher absorbsion voltage limit. Ypur charger algorithim is very light on permitted absorbsion. Is there any way to reboot the charger protocol? Tjat would make things easier.
  • Why doesn't the WM / JCI website provide the proper 3-stage recharge values for their Deep Cycle batteries, like US Battery and most other manufacturers do?

    I see that you recommend 60 percent SOC remaining. I use about 30 Amp-Hours each night. That is perfect, because that means I am using about 40 percent of the 90 Amp-Hours C/20 rating. I have never used 50 percent. So far, the battery has been functioning perfectly for 18 months.

    The RRC, Repetitive Reserve Capacity, rating is only 65 CYCLES! But I already have 100 CYCLES @ 40 percent DOD, in just 18 months. My goal is to get, at least 200+ cycles over a 3 - 4 year period.

    The only information on my 27DC battery is: "109 AH @ 1 Amp".
    Yesterday, at WM, I saw: "80 AH at 20 Amps" on the new 27DC batteries!
    If true, then the C 20Hr rating of my WM 27DC is somewhere, in between those two values?
    Maybe, 90AH @ 4.5 Amps C 20Hr rated battery?

    _ 109 AH @ 1.0 Amps = C 109Hr (old label)
    __ 90 AH @ 4.5 Amps = C 20Hr ???
    __ 80 AH @ 20. Amps = C 4Hr (new label)

    RE: ABSORB VOLTAGE ...
    At 80 Degrees, the Absorb Voltage is 14.4 volts
    At 70 Degrees, the Absorb Voltage is 14.5 Volts

    Yes, I can increase the Absorb Voltage.
    What Absorb Voltage do you recommend?

    How many 40% DOD /60% SOC Cycles do you think I will get?
  • My label states "Distributed by: Johnson Controls Battery Group, Inc".
    Is JCI the manufacturer or just a distributor?

    OK, I will look for "bubbles" when the Finish Stage hits 15.3 volts.
    Usually, the Finish Stage (@ 2 amps) takes about 1 hour to go from 14.4 volts to 15.3 volts.
    If I do not see bubbles, then I will HOLD the Finish Stage at 15.3 Volts until I see bubbles.

    #1 Bulk Constant Current = 8 amps until 14.4 volts
    #2 Absorb Constant Voltage = 14.4 volts until 2 amps
    #3 Finish Constant Current = 2 amps until 15.3 volts
    #4 Float Constant Voltage = 13.0 volts (forever at home)

    If I can get 300 cycles, then that is only $0.30 per cycle.
    That is a great value for a WM 27DC battery.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Your batteies are about 95 Amp Hour at the C/20 rate, Max charge current is thus around 31-32 amps. If you need voltages you can looke 'em up on most programmable Charger manuals as "Generic Maintenance Free.

    Everstart is a poor choice for a house battery, though there are worse ones.

    Reason: Too many bucks, not enough bang.
  • mvas wrote:

    #1 Bulk Constant Current = 8 amps until 14.4 volts
    #2 Absorb Constant Voltage = 14.4 volts until 2 amps
    #3 Finish Constant Current = 2 amps until 15.3 volts
    #4 Float Constant Voltage = 13.0 volts forever.


    Those numbers are perfect for any wet cell. Only thing to improve is to have temperature compensation.

    What charging system actually produces that profile?
  • as for "Wet" storage batteries. Johnson Control and Walmart does the same thing. Lowest bidder.

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