Lithium battery replacement for Gemini garage doors?

[quovadis]

Imho Overkill for a garage door. You can find quality lead acid options with higher cycles than the cheapies without the worry about having possible issues with the charger.

 

[Magnum]

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 line of a 12V battery with them.)

Safer yes. but there are more Strict conditions under which Phosphate batteries work. We have a couple dead New Cells already in a Year.

 

[Tim_vb]

Imho Overkill for a garage door. You can find quality lead acid options with higher cycles than the cheapies without the worry about having possible issues with the charger.

Please share some examples of the quality LA options, thanks

 

[L0uisc]

Imho Overkill for a garage door. You can find quality lead acid options with higher cycles than the cheapies without the worry about having possible issues with the charger.

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.

 

[L0uisc]

Safer yes. but there are more Strict conditions under which Phosphate batteries work. We have a couple dead New Cells already in a Year.

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.

 

[x7razor]

This is what i did with my 2 x centurion garage motors.

Got a blue nova battery with a step up converter and a separate charger. Hooked up the battery to step converter and set the voltage to 24vdc and set charger not to charge battery above 90% never looked back.

Obviously its not mounted inside the motor made a small rack and everything is mounted on that and it lasts longer then the LA 24v batteries at max it draws 3.1 amps with heavy wooden doors.

The blue nova can do 7.5A continuous the 1.44A stated in the specs is for longer service life all this is from blue nova's technical staff.

 

[capd]

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

What sort of life have you been getting out of your lead-acids? I would guesstimate that mine – in gate motors, garage motors, alarm systems and electric fences – have lasted at least 5 - 10 years.

They also cost 1/5 of what lithium replacements would. In my experience, lithium batteries kept constantly charged have not lasted long enough to warrant the shift away from lead-acid in the above applications.

But perhaps I'm wrong.

 

[agentrfr]

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.

It's not the load rating that is the issue for lithium batteries, it is the burst.

Remember, the stator is a low resistance series inductor until back EMF is generated. You can pull 100s of amps even on small motors for a few hundred milliseconds - orders of magnitude greater than running current. With lead acid batteries, this is not a problem since the internal resistance of the cells becomes significant and limits the current supplied. With lithium, the internal resistance is not significant enough to act as a current regulation mechanism.

Like you *can* use a lithium iron battery for a gate motor (if so then please add a capacitor of like 10mF 35V to the wire terminals on the control board), its just a waste of time, effort and money.

You have to baby lithium batteries - which is worth it if you cycle them regularly, but not if they are just on standby.

If you oversize your lead batteries, it will cost 1/4 and last 5 years, by then most people are moving out anyway

 

[supersunbird]

Yeah no, you cant series the batteries unless their BMSes can communicate with each other and know that they are in series (and in which order)

Also, OP would need to use two of the 11Ah batteries for the current draw, which is like R1150 each battery

Much easier to just do two 7Ah lead acid batteries methinks (~R300 each)

If you want to series the batteries (like in my 2 battery UPS) you have to buy 2 batteries with the same batch numbers, according to Blue Nova.

 

[L0uisc]

What sort of life have you been getting out of your lead-acids? I would guesstimate that mine – in gate motors, garage motors, alarm systems and electric fences – have lasted at least 5 - 10 years.

They also cost 1/5 of what lithium replacements would. In my experience, lithium batteries kept constantly charged have not lasted long enough to warrant the shift away from lead-acid in the above applications.

But perhaps I'm wrong.

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 for about 2 times and then it's gone. Not that lead-acid on average don't last.

 

[L0uisc]

It's not the load rating that is the issue for lithium batteries, it is the burst.

Remember, the stator is a low resistance series inductor until back EMF is generated. You can pull 100s of amps even on small motors for a few hundred milliseconds - orders of magnitude greater than running current. With lead acid batteries, this is not a problem since the internal resistance of the cells becomes significant and limits the current supplied. With lithium, the internal resistance is not significant enough to act as a current regulation mechanism.

Like you *can* use a lithium iron battery for a gate motor (if so then please add a capacitor of like 10mF 35V to the wire terminals on the control board), its just a waste of time, effort and money.

You have to baby lithium batteries - which is worth it if you cycle them regularly, but not if they are just on standby.

If you oversize your lead batteries, it will cost 1/4 and last 5 years, by then most people are moving out anyway

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 times use out of it before they just don't open the door any more. I don't want to just replace. That seems like throwing money away.

I want to do something to solve my issue. A small board with some electronics in between the BAT+ and BAT- outputs from the controller board and the batteries is also an option. I just thought it's not worth it if you go to that lengths to not simultaneously just convert to LiFePO4.

 

[furpile]

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 times use out of it before they just don't open the door any more. I don't want to just replace. That seems like throwing money away.

I want to do something to solve my issue. A small board with some electronics in between the BAT+ and BAT- outputs from the controller board and the batteries is also an option. I just thought it's not worth it if you go to that lengths to not simultaneously just convert to LiFePO4.

I have the same issue, but with the Centurion Xtrac door opener. It uses 2x 3Ah batteries I think (more square than the one you posted). Most of the references in this thread has been to 7Ah batteries, where you have some options, but not with these 2.4 Ah or 3 Ah batteries. I replaced mine after a few years, but the new ones are already struggling. No idea why they put 2x 7Ah batteries on a gate but 2x 3Ah batteries on a garage door. If you operate the door multiple times it already slows down even with mains. The batteries just can't keep up. Next time I am replacing with 2x 7Ah batteries located outside the enclosure.

 

[agentrfr]

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 times use out of it before they just don't open the door any more. I don't want to just replace. That seems like throwing money away.

I want to do something to solve my issue. A small board with some electronics in between the BAT+ and BAT- outputs from the controller board and the batteries is also an option. I just thought it's not worth it if you go to that lengths to not simultaneously just convert to LiFePO4.

Lithium BMS will just open circuit if current goes too high - it can not regulate current

You dont need a BMS for lead acid - overvoltage leads to offgassing and heat, not damage to the cells (with lithium if it is overcharged then the interstitial ions migrate all the way to the backside of the electrode and short, hence explosive youtube videos)

The micro dead acid batteries are not lasting long because the relative current draw is so high that the surface of the cathode is depleted, and during the charging cycle it promotes the formation of dendrites along the uneven surface.

100% all your problems go away if you just use bigger lead acid batteries. Get two 7Ah 12V ones and extend the leads outside of the box (use at least 3mm^2 wires and proper terminal connectors) and youll be set

 

[agentrfr]

*** overvoltage of lead acid will eventually consume all of the water, so dont do that intentionally. Rather, if your charger is set at 13.8 or even 14.4 per 12V battery (i.e, 2.4V per lead-acid cell), then it is set and forget, and you do not need to worry about battery voltage imbalances

 

[L0uisc]

*** overvoltage of lead acid will eventually consume all of the water, so dont do that intentionally. Rather, if your charger is set at 13.8 or even 14.4 per 12V battery (i.e, 2.4V per lead-acid cell), then it is set and forget, and you do not need to worry about battery voltage imbalances

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