Forum Discussion

RedRocket204's avatar
RedRocket204
Explorer
Aug 30, 2017

Grape 40 Amp PWM Charge Controller versus ?

I often see recommendations for the Grape Solar GS-PWM-40BT 40 Amp PWM Solar Charge Controller. The Grape controller was recommended as a potential replacement for my Renogy 30A PWM LCD Controller and I'm not discounting the advice. However, I'd like to know a bit more specifics behind the recommendations.

I moved forward with my installation of a Renogy 200W kit, which as mentioned included the Renogy PWM 30A LCD Controller. It is the one with an identical form factor of the Grape GS-PWM-40BT. Even though it has the same form factor, I feel confident that the internals are different. Grape having 40A capability versus the Renogy at 30A. Grape also having the remote BT connection capability where the Renogy does not. Even stranger is that both Controllers use the exact same manual layout minus name changes... at least that is what I recall from when I looked through both manuals 4 weeks ago.

I'm currently running (2) 100W Renogy panels along with the Renogy 30A PWM LCD Controller with (2) 12V Group 24 flooded batteries. I recently took a 5 day boondocking trip, no shade cast on the panels, and the batteries seemed very quick to recharge. Although I did not have extensive energy demands, at least I believe, on the batteries. 2 people using ~ 4 LED lights for a few hours, Fridge running on PP, PP detector, Direct wired USB ports for charging 2 cell phones, Water pump for 2 showers daily, and the furnace which did get used as mornings were 29f at 9,500 feet elevation.

Back to the recommendation for Grape aside from the 10A delta and BT capability. What is the reason for the Grape recommendation? Is it related to efficiency, longevity, better internal build quality for charging, support?

Again, I'm not discounting the advice, just looking for answers as to specifics on why the recommendation. Thank you in advance for any responses.
  • red31's avatar
    red31
    Explorer
    Aug 30, 2017
    RedRocket204 wrote:

    Then it would appear the main differences are the 10A delta and most importantly, the ability to fine tune the charge programming via BT.


    correct, the grape version comes with the optional BT, which is apparently available on the 30,40,50 & 60A versions. Remote monitoring is useful as is programming but not absolutely necessary. Some folks would find a remote temp or voltage probe more useful.

    renogy rebrands several different 30A w/LCD and that is why I provided the link for you to determine if you have the srne version.

    your system makes a great maintainer when not camping!
  • RedRocket204's avatar
    RedRocket204
    Explorer
    Aug 30, 2017
    MrWizard wrote:
    The primary thing is the ability to program almost every single setting
    Max charge voltage , boost time duration, low voltage return to boost mode, float flat voltage, i have no way y to know if it's more efficient aka (less internal loss)
    But it is the most user adaptible controller i have come across
    Mine is set so low voltage return to boost is the same voltage as float
    If the voltage drops to lie set point , when i use the MW then, it goes right back to boost mode, aka set charge of voltage 14.8 , and not set around in float mode

    You may not need the ability to do this, for me this is very helpful



    10-4, makes sense.


    I hadn't read the Tech Specs before, just did and the trailing two numbers of the model numbers is the rated Amps. That would indicate I most likely do have a 30A SR-HP2430.

    Then it would appear the main differences are the 10A delta and most importantly, the ability to fine tune the charge programming via BT.


    Again, appreciate all the comments, and keep 'em coming, as this is helping me to learn.
  • time2roll's avatar
    time2roll
    Nomad
    Aug 30, 2017
    I prefer an automatic adjusting absorption time. Fully charged in storage may only need 15 minutes of 14.5+ volts each day and while in use you may want 3+ hours of absorption.
  • MrWizard's avatar
    MrWizard
    Moderator
    Aug 30, 2017
    The primary thing is the ability to program almost every single setting
    Max charge voltage , boost time duration, low voltage return to boost mode, float flat voltage, i have no way y to know if it's more efficient aka (less internal loss)
    But it is the most user adaptible controller i have come across
    Mine is set so low voltage return to boost is the same voltage as float
    If the voltage drops to lie set point , when i use the MW then, it goes right back to boost mode, aka set charge of voltage 14.8 , and not set around in float mode

    You may not need the ability to do this, for me this is very helpful
  • mike-s's avatar
    mike-s
    Explorer
    Aug 30, 2017
    The thing I don't like about all these Chinese controllers is that they're positive ground, which makes the load terminal (and its ability to shut down a load before the battery is over discharged) useless on an RV, where pretty much everything is negative grounded.
  • RedRocket204's avatar
    RedRocket204
    Explorer
    Aug 30, 2017
    Thank you for that link. I had not seen that before. Yes, that looks to be exactly the same controller I have but I am unable to confirm the model number as it is in storage 30 minutes away at the moment.

    Renogy doesn't list that controller for sale anymore on their home page, my kit was purchased via Amazon and the kit with that Controller is probably being phased out. I haven't found any documentation that lists the exact Controller model number, but mine is the RoHS type with LCD and two red buttons. Renogy states 30A, but I'm not convinced their info is stated for accuracy on the controller, more so for the kit with Renogy's panels for expansion to 400W.

    Exact kit I bought: Renogy 200 Watt 12 Volt Monocrystalline Solar Starter Kit with 30A PWM Controller - LCD Display

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