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My battery box project

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#1 jlecomte

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Posted 11 April 2021 - 07:08 PM

Hi everyone! I wanted to share a few photos of my battery box project, in case it helps anyone on this forum, just like other's posts have helped me design and build this.

 

Here is a photo of the completed battery setup (powering my laptop for a test). The entire battery box weighs 20 lbs.

 

IMG_4330.jpg

 

I wired two 36 A-h Miady LiFePo4 batteries in parallel:

 

IMG_4331.jpg

 

On the front, there is a master switch and a digital volt/amp meter:

 

IMG_4334.jpg

 

On the back, there is a QC 3.0 Dual USB port, a cigarette lighter socket (both activated by a switch so I can turn them off, I don't need those at night and the QC 3.0 Dual USB port has a fairly bright blue glow around it...), and two 5.5 x 2.1 mm female output jacks, one at 12V connecting to the Pegasus Astro Powerbox Advance or to the charger, and one at 19V (behind a boost converter) to power my laptop:

 

IMG_4335.jpg

 

All the wiring is between the two batteries. It's a bit of a mess, but it's workable:

 

IMG_4326.jpg

 

On this last photograph, you can see how the batteries are connected in parallel (note: since taking this photograph, I bent one of the connectors, leaving a 1/2" gap between the red and black wires connecting the batteries, just because I am a little paranoid with safety...) You also can see an inline fuse (15A), a fuse box (hard to see, bolted to the piece of wood at the bottom), the boost converter, and a bus bar to keep things somewhat organized...

 

Links to supplies:

Of course, you'll also need wires (I used what I had in my garage, which was a combination of 12, 14 and 16 gauge wires, each strategically placed, but be sure to check the AWG chart to get the proper gauge wires for your specific setup), crimp connectors, heat shrink tubing, etc.

 

This powers the following equipment:

  • iOptron CEM70
  • ZWO ASI533MC Pro
  • ZWO EAF
  • ZWO EFW
  • 2 dew heater bands, 1 for the guide scope and 1 for the main scope (a 130mm refractor)
  • Pegasus Astro Powerbox Advance with environment sensor, to automatically adjust the power to the dew heater bands
  • A cheap ASUS laptop..

The next step is to get a 100W foldable solar panel and a solar charge controller so that I can go off grid for many days and keep imaging away.

 

All in all, this was a fun project. It's all pretty simple, but you have to use common sense and do a bit of reading before ordering things. Also, draw a wiring diagram, it is very helpful! (I purposefully did not post my wiring diagram because you should think about your own needs and draw your own diagram instead of just copying mine, this will force you to ask yourself the right questions...)

 

I hope this helps. Take care, and clear skies! (although California could use a bit of rain between new moons...)

 

- Julien (San Jose, CA)


Edited by jlecomte, 12 April 2021 - 10:20 AM.

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#2 Xeroid

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Posted 11 April 2021 - 07:19 PM

Great job but...but....where's the handle for the box?

lol.gif



#3 jfaldo

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Posted 11 April 2021 - 07:26 PM

Nice build. On my list to build another one. Just don't have the time right now. Really like that little volt / ammeter need to get one of those.



#4 astrohamp

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Posted 11 April 2021 - 09:54 PM

Nice build jle', as you have packed quite a bit into your box. 

For my boat anchor box I decided to run twin solar panels in series and plug them into an MPPT charge controller.  Any line losses are less of an issue at the high voltage side then they would be at nominal 12v charging currents.  The MPPT charging is also more efficient at using what ever power is available.  Voltage and associated power above 13.5-14.4v is not wasted and lost. With MPPT charging it is converted to higher associated power into the battery when needed.

 



#5 t-ara-fan

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Posted 11 April 2021 - 10:44 PM

Nice box. Using Li made it quite light. I think my SLA with the same capacity is 50. pounds.

 

 , and two 5.5 x 2.1 mm female output jacks, one at 12V connecting to the Pegasus Astro Powerbox Advance or to the charger, and one at 19V (behind a boost converter) to power my laptop:

That might be dangerous if a sleepy guy is plugging in stuff in the middle of the night. I always make my connections idiot-proof (me-proof). Example:  I have 12V and 8.4v for my DSLR coming out of the same box.   The 8.4V is on a 1.55mm barrel connector and the 12V on a 2.1mm connector. So there is no way I can put 12V into my 8.4V camera.


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#6 jlecomte

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Posted 11 April 2021 - 10:52 PM

Where's the handle for the box?

There is a handle on either end of the box, but no top handle. I like it better that way as it forces me to lift it with both hands. I broke out my back too many times lifting heavy things with only one hand... Including a sock off the floor lol.gif

 

I always make my connections idiot-proof [...]

Yeah, I thought about that after I was done building the battery box. You are 100% right. Maybe I'll change it later on, it shouldn't be too difficult or time consuming.


Edited by jlecomte, 11 April 2021 - 10:53 PM.


#7 jeffcrilly2

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Posted 11 April 2021 - 11:28 PM

The battery box looks great!  After many years of using the Optima YellowTops, I'm gradually moving to lighter weight (smaller) SLAs and LiFePO4-based batteries... I'm slowly moving towards building a battery power center to run the camera at 12v with a step-up converter to run the mount at 24v.   I've found for most "single night" outings, I don't need the full capacity of the heavy YellowTop (except maybe when the dew heater is being used), and a small 12v 18Ah AGM can be used to run the mount all night long.

I probably missed something .... how do you charge these batteries?

 

Also.. re the parallel batteries... I'm not an expert here .. but ... I thought this configuration could potentially result in one battery "charging the other" (if the capacities are different).    IIRC there's usually a BMS to balance the batteries, and possibly a diode to prevent one battery from charging the other.    If the batteries are well matched (e.g. from the same manufacturing batch?) then presumably the discharge rate will be the same.

 

Btw.. regarding the "power output" connections... fwiw, I've pretty much switched everything to Anderson powerpoles.  

E.g. https://powerwerx.co...werpole-housing

... that's an "outlet", but these connectors can also be put on the end of a cable.

The powerpole is a "firm" connector, but not too firm that the cable would break if accidentally yanked (like a switchcraft locking connector).

 

Let us know how the solar panels and charger works out!

 

thx

 

-Jeff



#8 jlecomte

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Posted 12 April 2021 - 11:43 AM

 

How do you charge these batteries?

 

Right now, I just connect it to A/C power using this charger: https://www.amazon.c...duct/B08MPX414R, which comes with a 5.5 x 2.1 mm DC male jack that I connect to the female power jack labelled "12V" on the battery box. That being said, I will also soon invest in a cheap, foldable 100W solar panel and solar charge controller, so that I can charge it during the day when I am far from any A/C outlet (like in the middle of Death Valley...)

 

 

re the parallel batteries... I'm not an expert here .. but ... I thought this configuration could potentially result in one battery "charging the other"

 

Before connecting the two batteries, it is critical to make sure that they are within 0.2V from one another. This is done by fully charging them and letting them settle for an hour. Once connected, for a short amount of time, one battery might charge the other, until they equalize. Also, when charging, they equalize during the last phase of the charging sequence. I did some research online, and it is supposed to work reliably.

 

 

I've pretty much switched everything to Anderson powerpoles

 

Yup, they are a lot more flexible. I thought about it too late for this project, but I agree with you that it is a better option.

 

 

Let us know how the solar panels and charger works out!

 

Will do! Thanks, Jeff.



#9 Geokolb1

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Posted 12 April 2021 - 09:36 PM

Hi everyone! I wanted to share a few photos of my battery box project, in case it helps anyone on this forum, just like other's posts have helped me design and build this.

 

Here is a photo of the completed battery setup (powering my laptop for a test). The entire battery box weighs 20 lbs.

 

attachicon.gifIMG_4330.jpg

 

I wired two 36 A-h Miady LiFePo4 batteries in parallel:

 

attachicon.gifIMG_4331.jpg

 

On the front, there is a master switch and a digital volt/amp meter:

 

attachicon.gifIMG_4334.jpg

 

On the back, there is a QC 3.0 Dual USB port, a cigarette lighter socket (both activated by a switch so I can turn them off, I don't need those at night and the QC 3.0 Dual USB port has a fairly bright blue glow around it...), and two 5.5 x 2.1 mm female output jacks, one at 12V connecting to the Pegasus Astro Powerbox Advance or to the charger, and one at 19V (behind a boost converter) to power my laptop:

 

attachicon.gifIMG_4335.jpg

 

All the wiring is between the two batteries. It's a bit of a mess, but it's workable:

 

attachicon.gifIMG_4326.jpg

 

On this last photograph, you can see how the batteries are connected in parallel (note: since taking this photograph, I bent one of the connectors, leaving a 1/2" gap between the red and black wires connecting the batteries, just because I am a little paranoid with safety...) You also can see an inline fuse (15A), a fuse box (hard to see, bolted to the piece of wood at the bottom), the boost converter, and a bus bar to keep things somewhat organized...

 

Links to supplies:

Of course, you'll also need wires (I used what I had in my garage, which was a combination of 12, 14 and 16 gauge wires, each strategically placed, but be sure to check the AWG chart to get the proper gauge wires for your specific setup), crimp connectors, heat shrink tubing, etc.

 

This powers the following equipment:

  • iOptron CEM70
  • ZWO ASI533MC Pro
  • ZWO EAF
  • ZWO EFW
  • 2 dew heater bands, 1 for the guide scope and 1 for the main scope (a 130mm refractor)
  • Pegasus Astro Powerbox Advance with environment sensor, to automatically adjust the power to the dew heater bands
  • A cheap ASUS laptop..

The next step is to get a 100W foldable solar panel and a solar charge controller so that I can go off grid for many days and keep imaging away.

 

All in all, this was a fun project. It's all pretty simple, but you have to use common sense and do a bit of reading before ordering things. Also, draw a wiring diagram, it is very helpful! (I purposefully did not post my wiring diagram because you should think about your own needs and draw your own diagram instead of just copying mine, this will force you to ask yourself the right questions...)

 

I hope this helps. Take care, and clear skies! (although California could use a bit of rain between new moons...)

 

- Julien (San Jose, CA)

Nice job.  One suggestion:  you should “tap’ the bank with the positive lead from one battery and the negative lead from the other battery ensuring applying the load to both batteries.



#10 jlecomte

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Posted 14 April 2021 - 09:30 AM

 

One suggestion:  you should “tap’ the bank with the positive lead from one battery and the negative lead from the other battery ensuring applying the load to both batteries.

@Geokolb1 I am sorry, but I don't understand your suggestion. What do you mean by "tap the bank"? Thanks!



#11 jeffcrilly2

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Posted 16 April 2021 - 01:31 AM

@Geokolb1 I am sorry, but I don't understand your suggestion. What do you mean by "tap the bank"? Thanks!

I think he means to wire the negative on the output port to the negative of the other battery.

This way if there is a problem with "parallel" wires then the one battery won't just keep discharging.

Also.. possibly there is a slight voltage drop with the parallel wires.

This alternative wiring ensures both batteries are being used.

(Of course the fuse needs to be moved also.)

 

Attached is an annotated pick with the suggest changes (if I understand the suggestion correctly).

 

I'm not exactly sure how the output is wired... I think in the pic I'm referring to the charger input (maybe?)

Anyhow, I think you can see the point of "tapping" the negative from the other battery.

 

Edit:  OK.. that looks like the power switch.   It appears the negative off the other battery is tucked underneath the rest of the wiring.. but I think you will probably get the idea.

Attached Thumbnails

  • battery.jpg

Edited by jeffcrilly2, 16 April 2021 - 01:34 AM.

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#12 philinbris

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Posted 16 April 2021 - 04:09 AM

I think he means to wire the negative on the output port to the negative of the other battery.

That is technically correct and exactly what I did with my dual LiPoFe4 setup.

And yes, super important that before you parallel 2 or more batteries they are close in voltage (my supplier said 0.5V but I am happier with the closer 0.2V).

Cheers
 



#13 t-ara-fan

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Posted 16 April 2021 - 04:34 PM

  • Volt/amp meter:

Did you check how accurate that meter is? I have one like that which reads 0.2V low.  Not impressive, 1.5% error.  I bought mine from the same place you did.

 

 



#14 jlecomte

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Posted 17 April 2021 - 12:03 AM

Thanks for the tip on the wiring, guys, I will make that change. Pretty straightforward!

 

 

Did you check how accurate that meter is? I have one like that which reads 0.2V low.  Not impressive, 1.5% error.  I bought mine from the same place you did.

 

My unit seems very accurate. It gives me the same readings as my multimeter.



#15 AstroStock

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Posted 28 April 2021 - 02:25 PM

Hi everyone! I wanted to share a few photos of my battery box project, in case it helps anyone on this forum, just like other's posts have helped me design and build this.

 

Here is a photo of the completed battery setup (powering my laptop for a test). The entire battery box weighs 20 lbs.

 

attachicon.gifIMG_4330.jpg

 

I wired two 36 A-h Miady LiFePo4 batteries in parallel:

 

attachicon.gifIMG_4331.jpg

 

On the front, there is a master switch and a digital volt/amp meter:

 

attachicon.gifIMG_4334.jpg

 

On the back, there is a QC 3.0 Dual USB port, a cigarette lighter socket (both activated by a switch so I can turn them off, I don't need those at night and the QC 3.0 Dual USB port has a fairly bright blue glow around it...), and two 5.5 x 2.1 mm female output jacks, one at 12V connecting to the Pegasus Astro Powerbox Advance or to the charger, and one at 19V (behind a boost converter) to power my laptop:

 

attachicon.gifIMG_4335.jpg

 

All the wiring is between the two batteries. It's a bit of a mess, but it's workable:

 

attachicon.gifIMG_4326.jpg

 

On this last photograph, you can see how the batteries are connected in parallel (note: since taking this photograph, I bent one of the connectors, leaving a 1/2" gap between the red and black wires connecting the batteries, just because I am a little paranoid with safety...) You also can see an inline fuse (15A), a fuse box (hard to see, bolted to the piece of wood at the bottom), the boost converter, and a bus bar to keep things somewhat organized...

 

Links to supplies:

Of course, you'll also need wires (I used what I had in my garage, which was a combination of 12, 14 and 16 gauge wires, each strategically placed, but be sure to check the AWG chart to get the proper gauge wires for your specific setup), crimp connectors, heat shrink tubing, etc.

 

This powers the following equipment:

  • iOptron CEM70
  • ZWO ASI533MC Pro
  • ZWO EAF
  • ZWO EFW
  • 2 dew heater bands, 1 for the guide scope and 1 for the main scope (a 130mm refractor)
  • Pegasus Astro Powerbox Advance with environment sensor, to automatically adjust the power to the dew heater bands
  • A cheap ASUS laptop..

The next step is to get a 100W foldable solar panel and a solar charge controller so that I can go off grid for many days and keep imaging away.

 

All in all, this was a fun project. It's all pretty simple, but you have to use common sense and do a bit of reading before ordering things. Also, draw a wiring diagram, it is very helpful! (I purposefully did not post my wiring diagram because you should think about your own needs and draw your own diagram instead of just copying mine, this will force you to ask yourself the right questions...)

 

I hope this helps. Take care, and clear skies! (although California could use a bit of rain between new moons...)

 

- Julien (San Jose, CA)

Thank you for sharing this! Can you share any ideas of run and charge times to expect for this setup?


Edited by AstroStock, 28 April 2021 - 02:27 PM.


#16 jlecomte

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Posted 28 April 2021 - 11:22 PM

 

Thank you for sharing this! Can you share any ideas of run and charge times to expect for this setup?

This battery is big enough to power my entire rig (see original post for the list of components) for 2 full nights. Charging from A/C power takes between 4 and 10 hours depending on how drained the battery is. It is a good idea to not drain batteries too much so that they have a long life.


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#17 Eddie_42

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Posted 01 May 2021 - 12:23 PM

Thats a great project, well done.

 

Ive been rolling around the idea of finally building a battery box, selecting AGM/LiFePO, and all the other fun that comes with it.  Aiming to build a system that can run a couple nights (weekend) camping off-grid.  You gave me some good ideas, and a bit of motivation.



#18 jlecomte

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Posted 01 May 2021 - 06:05 PM

 

You gave me some good ideas, and a bit of motivation.

Glad I did. This is what this forum is all about. Helping each other out. I got so much from CN, I figured it was time to give something back.

 

I tested my solar setup to charge this battery in remote areas (I will use it next week, hopefully) and it is looking good! I will post an update here.


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#19 Eddie_42

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Posted 02 May 2021 - 08:40 AM

Which solar panel did you end up with?  20A controller?  PMW or MPPT?   Curiosity kills the cat..and the bank account.  I was about set on a 55aH AGM battery, but looking at yours I think to myself.....gosh, for twice the price I could make a nice rig.

 

Im not very electrically adept, did you have to do anything special in the circuit for the input/charge? Or is it really as simple as you made it seem?



#20 jlecomte

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Posted 02 May 2021 - 11:23 AM

Since you all have been on the edge of your seat, here is what I did to charge my battery box using solar panels...

 

Equipment:

 

Photos:

 

IMG_4361.jpg

 

IMG_4362.jpg

 

The solar panel is really great. I wholeheartedly recommend it! It folds up nicely and takes almost no room when stored.

 

As far as the solar charge controller, I *really* don't think an expensive MPPT is needed. Those are more appropriate for large solar installations from what I understand. For our use, a cheap PWM charge controller works fine.

 

If I were to re-do this project from scratch, I would improve the integration so that I don't have to open the box every time I want to charge it. I would also use different types of ports to avoid mistakes as was stated above in this thread. Oh well, those are relatively minor. This setup works amazingly well, and it has more than enough capacity to power all of my equipment for 2 nights before needing to recharge (and even then, it would have quite a bit of charge left, which is a good thing)

 

Hope this helps!


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