Grape Solar 40A PWM controller

[RDMueller]

Hi all,

Decided it's time to get into solar! Got a Grape Solar 40A PWM controller and a single 100W panel for starters. My batteries are 2 Trojan T105s.

Have some questions about setting up the controller. It doesn't come with a user manual, just a little one page leaflet with some basic info. There is also an app that you can use to set it up, but I can't find any documentation on how to use the app.

I took these screen shots of the app:





Here's the charging profile I've been using (recommended by Trojan):



There are quite a few fields in the app that I'm not sure what they mean or what to plug in. For example:

Boost Char Return Volt
Over Disc Reture Volt
Temperature Compensation

Also, not totally sure what to plug into some of the other fields to get the desired profile. For example, I've been doing manual absorption charging using a Drok buck booster. I charge at a fixed 14.8V until charge amperage drops to a constant value (usually about 2.5A). Then raise it to 16.2V for a finish voltage at a constant amperage and shut it off when the voltage stops rising.

I have no idea how to set up the Grape to achieve a similar profile. The app doesn't even have any mention of absorption charging.

I know there are at least a few here that are using this controller. I'd love to hear how you set it up and how it's working out for you.

[RDMueller]

Next good sunny day I get, I'll give that a try. I guess it's possible that hitting "read" just brings up the default numbers. Only way to be sure is an actual test.

[red31]

I'd set the voltage you like and then see what voltage the controller uses.

The USB is only for power.

[RDMueller]

I downloaded the RenogyBT app and it looks pretty similar to the Grape version. Not exact, but definitely similar. It connected to the controller with no problem but now seems to have the same issue where most of the parameters can't be changed. Well, they can be changed but then revert back to the default numbers when you hit read.

I asked their tech support guy about connecting to a tablet with the USB port and he seemed to think it wasn't for data, but instead just a way to charge a phone or tablet. Might just give it a try though, you never know!

[red31]

I would certanly try the ios version RenogyBT

https://itunes.apple.com/us/app/renogy-bt/id1251320287?mt=8

[red31]

RDMueller

I'd certainly change to user and try changing there. If it don't work then an old tablet! as I understand, MrWiz uses an ole table connected via the USB for power and runs the app, uses the tablet as the display/monitor.

[RDMueller]

Do you think this app will work with the Grape controller?

I spent some more time yesterday trying to make changes with the app to no avail. The only parameters that will "stick," so to speak, are the battery type, battery rated Ah, over disc return V, and the disc limit V. All of those except the rated Ah are adjustable on the controller itself.

The other values I want to change like the boost V, float V, temp compensation and the time values are totally unchangable with the app so far. My guess is that the iOS app is the issue since people with androids can program it just fine.

[red31]

renogy has a newer android app, requires changing to user to change voltages

Different color also!

[red31]

still not enough sun to determine if it is using 14.9v.
I'm on SLD, I've had issues with voltage settings but none with load control, abs time, equal time ... Never tried user.

edit : controller using 14.9v

[RDMueller]

I'll give that a try. Sounds like android has similar issues. In my case though, even one "read" causes it to go back to default numbers.

In your case, do you set battery type to "user" or do you select your actual type of battery? I started to think that if you select a battery type such as flooded, it has a set of default numbers for that battery type that can't be changed and you must use "user" if you want to use your own numbers. Only problem, I can't get it to stay on user. Even one "read" and it's right back to flooded.

[red31]

android

I set boost to 14.9v, if I 'read' more than once it reverts to default 14.4v.

close app and reconnect it show 14.9v, a 'read' will revert to 14.4v

I'll have to wait several hrs to determine if it is using 14.9 or 14.4!

[RDMueller]

Yes, I was close, just a couple of feet away with a solid connection. I wish I had an android device to try on it, but I don't. At this point, I don't know if it's the controller itself or the app.

On a side note, no problem changing the battery amp hours or battery type (as long as you don't select "user").

[MrWizard]

it might be that the grape controller as a weak BT radio

are right in front of it?
inside but 15ft away ?
the closer you are the better for staying connected

sorry but i have android

[grizzzman]

I had to dink around with the software to get it to take on my father in laws grape solar charger to make changes. There were several times that I had several do overs to get it to take.
Also it kept disconnecting and reconnecting. I believe in my case I had to make the change during connected state or it would not take.

I think the software is a bit immature at this time.

[RDMueller]

Yes, I did log in as the administrator. In fact, if you don't, it asks for the password when you press the "set" button.