Recent content by L0uisc

Ok yes, so it would seem like Gemini used underspecified batteries for the application and that's the reason for them not lasting.

Wouldn't a battery charger board + BMS limit the current, simulating the internal resistance increase? To be clear, I would also be fine with a solution for a lead-acid BMS. As I noted above, these specific lead acid batteries in this specific application lasts ~1 year maybe. We get maybe 5...

About 1 year, maybe 2 if you're lucky on these specific batteries. The lead-acid in the gate motor (Centurion D5) is still going strong after maybe about 5 years now. The issue I have is that the specific lead-acid batteries in the Gemini garage doors don't last. Like, you have battery backup...

We use a LiFePO4 battery pack for one of our products at work. Never had issues with it. Granted, it's a 3.2V battery powering an OLED display, microcontroller and sub-GHz RF module.

The issue is that I can't find too many batteries in that shape. Seems like they're specially designed by Gemini to fit in their door motor enclosure. I don't think there are many different options in that form factor.

LiFePO4? Because AFAICT LiFePO4's main selling point is that it's almost as good as Li-ion in terms of energy density, but much safer. Which is part of the reason why I wanted to go with them. (The other part being they are 3.2V nominal, not 3.6 or 3.7V, so it is easier to get something in the...

@agentrfr this LiFePO4 cell is rated at 46A max continuous discharge current at 2300 mAh capacity. I think one need to select the right cell, but there are LiFePO4 options which can handle the discharge current of my application.

The motor is rated at <=4.5 A under load. I can't find the max discharge current rating for the original batteries. A quick look around made me aware of some LiFePO4 cells with extra high C ratings. That might also be an option.

Battery life. Those lead-acid batteries don't last.

Yes, as far as I can tell that is exactly what happens.

I have looked at it, unfortunately it is not in the right size. It is too big to fit in the space left for battery in the Gemini garage door openers.

I'm looking for a Lithium (most likely LiFePO4 would be best) drop-in replacement for this Gemini garage door battery. I don't find anything in the physical dimensions of this battery. Am I missing something? If something like this doesn't exist, I'm willing to do some R&D to develop one and...