After a fine night of motorsailing, I've come to terms with the LiFePO4 battery

[tjspiel]

Ran the motor at full speed for nearly an hour and still had over 50% left according to the voltage reading. Good news there.

Also learned that Renogy doesn't do float charging with LiFePO4 batteries, which explains why I've never seen it in float mode.

And I think the solar panel is getting shut off by the charge controller at noon due to a setting.

So while I still wish I could get a clear state of charge from the controller, it does at least seem to be charging the battery right and the battery is operating fine as far as I can tell.

No complaints about the range it gave me.

[Quantico Frank]

That sounds pretty good to me for an hour, Tom. I don't THINK I would have gotten anything like that at full speed from my old Torqeedo Travel; but, of course, that's a completely different setup.

[tjspiel]

Yes, I'm good with what the battery is providing in terms of range.

Also the noon report today shows it charging rather than "charge not ready", probably because the battery was substantially discharged last night and will happily take whatever the solar panel can provide.

LiFePO4 pros over plain lead acid:

• More Ah in smaller, lighter package
• Less maintenance
• Longer life?

Cons:

• Over twice the cost (almost 3 X) of a quality deep cycle battery
• Built in battery meter on trolling motor and charge controller don't give accurate state of charge. Kind of flying blind *

* might be resolved by newer Renogy BT app. Otherwise you can spend $60 on a good battery monitor

If the new app fixes percent charged display, I'll be happy. Still not quite sure it's worth the extra money based on how I use it. I might have been better off money wise getting a regular lead acid battery this time around and then getting the LiFePO4 the next time since prices will undoubtedly have dropped.

[Straander]

I've never relied on my trolling motor's built in indicator anyway. I once hooked up a digital power supply to it and cycled through some voltages and the values they picked for when the 5-lights go out were very unrealistic.
I forget the numbers I found, but I think by the time the first light goes out, you're already 80-90% of recommended depletion of a deep-cycle SLA battery. You're below the recommended depletion by the time the second light went out. it didnt drop down to just 1 light left until something around 8.5Volts, Ie, your battery is basically trash at that point.

Yes, I'm good with what the battery is providing in terms of range.

Also the noon report today shows it charging rather than "charge not ready", probably because the battery was substantially discharged last night and will happily take whatever the solar panel can provide.

LiFePO4 pros over plain lead acid:

• More Ah in smaller, lighter package
• Less maintenance
• Longer life?

Cons:

• Over twice the cost (almost 3 X) of a quality deep cycle battery
• Built in battery meter on trolling motor and charge controller don't give accurate state of charge. Kind of flying blind *

* might be resolved by newer Renogy BT app. Otherwise you can spend $60 on a good battery monitor

If the new app fixes percent charged display, I'll be happy. Still not quite sure it's worth the extra money based on how I use it. I might have been better off money wise getting a regular lead acid battery this time around and then getting the LiFePO4 the next time since prices will undoubtedly have dropped.

[Straander]

I'm working on a project to manage and readout my battery charge metrics right now. I'll post about it after I've proven it out.

[tjspiel]

I'm working on a project to manage and readout my battery charge metrics right now. I'll post about it after I've proven it out.

Fabulous. I was hoping you'd respond to this thread.

I did find out that there's a few different Raspberry Pi projects that people have created for reading Renogy charge controller data via the Bluetooth module.

Looking through the source code of one of them it appears that the battery percent comes right from the controller and isn't calculated by the app based on voltage. So that means it's unlikely that the new app will work any better for that.

However, I do have at least one unused Raspberry Pi sitting around and this would be a great winter project. I can add a cell modem and then I wouldn't need to leave an old iPhone on the boat. Plus it would give me a lot more flexibility in how I record and report the data.

In the space of 48 hours I've gone from being somewhat disappointed with my LiFePO4 purchase to excited about the possibilities.