Advices for portable 12v deep cycle battery

[msacco]

Hello, I'm not sure it's the right place to ask, but I'm going to buy a 75 Ah 12V deep cycle battery soon, and I'll need to use it as a portable 12V power supply. The build should be quite simple, but I'd like to ask a few questions to make sure I'm doing everything the best and safest way I can.

So I'm planning on getting some sort of battery box, so it will be easy to carry and have all the cables sorted inside of it, I thought of having the following cables: I'd have 2 cigarette sockets, 1 for the main 12V output I'd need, and one more extra in case I'll need it in the future, 2 USB outputs, and a voltmeter so I'll know where I stand.

I'll also want to connect an on/off switch, for more safety etc. The last thing I'd maybe want to have, and I don't know if it's even possible, but some sort of charging port. I have a battery charger, but it has those crocodile clips, which means I'll need to open the box and connect it directly. That's not really hard or even messy, but I think that if I'll manage to make some sort of charging port, it will be easier, safer, and better overall.

Now I can sort of see in my head how I want to connect everything, doesn't seem too complex to me, but what I want to know is if there's something else I need, maybe a fuse? Or just anything else that you can think of that I might need for that, some general tips it's important to know, and just everything else that pops to you mind. Thanks!

 

[fourjeepin]

My local NAPA has plastic battery boxes for a good price. For the charger, I would cut off the alligator clips and plug into the cigarette lighter. Much quicker and easier than opening the box. I did this to the charger on my CJ. If something is quick and easy, I am more likely to do it.

 

[msacco]

My local NAPA has plastic battery boxes for a good price. For the charger, I would cut off the alligator clips and plug into the cigarette lighter. Much quicker and easier than opening the box. I did this to the charger on my CJ. If something is quick and easy, I am more likely to do it.

Unfortunately the alligator clips are needed for the battery charger so it needs to be a different way, I thought of making some sort of socket connector to the alligator clips, and then just plug it to the battery box, is that a good idea? And can you please tell me if there's other things I need to do?

 

[msacco]

Anyone else?

 

[Leaflessshadetree]

You might be better off by searching for power supply or power station (which is what you are describing). Anyway here are some links that might give you some ideas.

https://www.care.com/c/products/504...g-motor-smart-battery-box-power-center-black/

https://dbox12.com/products/dx300-12-volt-battery-box-with-outlets-and-charging-port

https://www.amazon.com/dp/B076PR4TBZ/?tag=atomicindus08-20

https://adventure-ready.com/store/engel-arkpak-portable-power-supply/

http://www.engelaustralia.com.au/products_details.asp?productid=21390

http://www.home12volt.com.au/bb-green-std.html

 

[msacco]

You might be better off by searching for power supply or power station (which is what you are describing). Anyway here are some links that might give you some ideas.

https://www.care.com/c/products/504...g-motor-smart-battery-box-power-center-black/

https://dbox12.com/products/dx300-12-volt-battery-box-with-outlets-and-charging-port

https://www.amazon.com/dp/B076PR4TBZ/?tag=atomicindus08-20

https://adventure-ready.com/store/engel-arkpak-portable-power-supply/

http://www.engelaustralia.com.au/products_details.asp?productid=21390

http://www.home12volt.com.au/bb-green-std.html

I searched for battery box videos, the links are not very useful, as I pretty much know what connectors I want in general, the video was nice tho, thanks

 

[Jeeper89]

Are you looking to build something similar to an ARKPAK ARK DA25? I have thought about building a few items like this for remote camping. I would also add a way to hook them to a solar panel for charging.

 

[msacco]

Are you looking to build something similar to an ARKPAK ARK DA25? I have thought about building a few items like this for remote camping. I would also add a way to hook them to a solar panel for charging.

I just googled it so from what it looks like yes, thats really what I want to build, maybe a bit simpler, but the general idea is the same. I don't know if I'd need to add a solar panel, as I'll use this battery for my telescope, and obviously it will be at night time, but I guess I might add a solar panel.

 

[toplessHO]

UPS battery might work
anderson connectors for the charger hook up if you want higher amps than a cigarette lighter
I just bought one of these for adding aux outlets

 

[Shiftless]

msacco:
How many watts will you need for your telescope drive and for how many hours?
Will you be out and away from power to recharge for more than one night at a time?
The answers to those questions will guide you in selecting the size battery you need. The portable power stations and the computer back up battery units are well designed, and far more portable than a group 24 or group 27 deep cycle battery. But those big heavy (over 50 pounds) batteries will store a very large amount of power. Guys with big motorhomes rely on them for house power when they can’t run generators or plug in to campsite shore power.

 

[msacco]

msacco:
How many watts will you need for your telescope drive and for how many hours?
Will you be out and away from power to recharge for more than one night at a time?
The answers to those questions will guide you in selecting the size battery you need. The portable power stations and the computer back up battery units are well designed, and far more portable than a group 24 or group 27 deep cycle battery. But those big heavy (over 50 pounds) batteries will store a very large amount of power. Guys with big motorhomes rely on them for house power when they can’t run generators or plug in to campsite shore power.

I probably need much less power than the 75 AH battery, I got a friend that works with batteries etc, and I can get the 75 AH battery for the same price as a 33 AH battery, so thats pretty awesome, the telescope should draw max of 12v 2A, and probably the average use is around 1A, there might be situations when I'll go for a few days trip, so the big battery is a nice extra for me, I could manage with much less probably, but if I already get one like this, and I might need to connect extra things in the future, so why not use it?
I made a simple sketch for what I want to do here:

Its very possible that I made mistakes, as Im not that familiar with this, but idk. https://www.aliexpress.com/item/3-1A-Dual-USB-Car-Charger-Cup-Charging-Voltage-Current-Display-Phone-Charger-With-2-Cigarette/32816336949.html? This is what I'll use as the main sockets shown in the sketch.
Any advices? Things I've done wrong? Anything else?

 

[Shiftless]

If you don’t mind the weight or the space required go BIG!
I have a 1000 watt inverter hooked up to my group 24 deep cycle. It can run a few LED lights just about forever. It has run a 1/3 HP sump pump more than once.

Out in the wild, you could run a blender and make frozen Margaritas.

 

[msacco]

If you don’t mind the weight or the space required go BIG!
I have a 1000 watt inverter hooked up to my group 24 deep cycle. It can run a few LED lights just about forever. It has run a 1/3 HP sump pump more than once.

Out in the wild, you could run a blender and make frozen Margaritas.

Haha the frozen margaritas sounds nice, but honestly I just need it for my telescope mount, which requires around 12v 2A, and average is probably around 0.5-1A, and maybe some phone charging and stuff like that in case I need, but overall, I don't need much. How is my sketch for now? Any advices? Something that needs to be fixed?

 

[toplessHO]

did you notice the USB ports in the adapter I posted?

 

[msacco]

did you notice the USB ports in the adapter I posted?

Yes, but I already have this: https://www.aliexpress.com/item/3-1...949.html?spm=a2g0s.9042311.0.0.2b594c4dgdujMZ
So I don't think I'll need something else.

 

[Shiftless]

Haha the frozen margaritas sounds nice, but honestly I just need it for my telescope mount, which requires around 12v 2A, and average is probably around 0.5-1A, and maybe some phone charging and stuff like that in case I need, but overall, I don't need much. How is my sketch for now? Any advices? Something that needs to be fixed?

How many hours will your telescope drive motor sit there drawing a constant half an amp?
Your sketch seems to have been posted using imagur which is for me at least incompatible with GJ. I can’t see it. Just post it directly on GJ using the paper clip icon in the tool bar. Remote image hosting seems to cause problems.

 

[msacco]

How many hours will your telescope drive motor sit there drawing a constant half an amp?
Your sketch seems to have been posted using imagur which is for me at least incompatible with GJ. I can’t see it. Just post it directly on GJ using the paper clip icon in the tool bar. Remote image hosting seems to cause problems.

I actually went to a little different direction, Im going to build something very similar to this:

 

[Shiftless]

That’s a cool build in the video. I watched the first few minutes.

The main question is how many amps do you need for how many hours. A very slick looking build is great, but if the battery runs down in the middle of the night when you want to use your telescope motor drive all is lost.

I suppose that the rig in the Plano box would work if you kept one or two extra batteries somewhere charged up. With the quick connectors inside, it would only take a few seconds to swap in a fresh battery. Kinda like our cordless drills...just run them down and if necessary, snap in a spare battery.

Good luck with your build and keep us updated as you make progress.

 

[msacco]

That’s a cool build in the video. I watched the first few minutes.

The main question is how many amps do you need for how many hours. A very slick looking build is great, but if the battery runs down in the middle of the night when you want to use your telescope motor drive all is lost.

I suppose that the rig in the Plano box would work if you kept one or two extra batteries somewhere charged up. With the quick connectors inside, it would only take a few seconds to swap in a fresh battery. Kinda like our cordless drills...just run them down and if necessary, snap in a spare battery.

Good luck with your build and keep us updated as you make progress.

Well I'd wanted to get like 3 10A li-ion batteries at first, but if I replace a battery, all the align I've done with the telescope needs to be done again, so its not a good solution, and I doubt I'll ever run out of power anytime soon, as Im using only the telescope mount atm, which draws max of 2A, and probably an average of 0.5A, so that will last for many many hours, even if I connect some other electronics, I'd probably use much less than what I have with a 75 AH battery.

 

[BillK]

Take a look at some of the stuff DX Engineering has for Ham Radio use:

https://www.dxengineering.com/searc...4294952899&SortBy=Default&SortOrder=Ascending

 

[theoldwizard1]

There are REAL deep cycle lead acid batteries and there DUAL PURPOSE deep cycle lead acid batteries. The dual purpose (usually sold as "marine" batteries) are a compromise and are nowhere near as robust a real deep cycle batteries.

Real deep cycle batteries can withstand MANY more charge/discharge cycles than other batteries because they have a different plate design. The bad news is, real 12V deep cycle batteries are very expensive and you can typically only buy them online or at a Solar/wind energy store.

The most cost effective way to get genuine deep cycle batteries is to use TWO 6V golf cart batteries. These are relatively cheap at Sams Club or Costco.


You need to learn how to read and interpret battery specification. Normal "starting" and "dual purpose" lead acid batteries are sold ny CCA or MCA, cold cranking amp or marine cranking amp. This is a batteries capability to deliver a lot of amps at a specific temperature. Useless information for your application.

Deep cycle batteries almost NEVER specify a CCA or MCA. If they do, then they are not true deep cycle batteries. Deep cycle batteries can be specified in different ways. Capacity in minutes at a specified discharge rate (usually 25A or 75A) or capacity in amp-hours for a specified number of hours. Most commonly they use a 20 hr period, but good batteries will specify it in several different periods up to 100 hours.

A pair of 6V golf cart batteries will give you about 200-230 AH at a 20 hour rate. Or to say it another way, they can deliver about 11A of power continuously for 20 hours. Starting/dual purpose batteries usually will not specify an AH discharge time at all.

 

[theoldwizard1]

... the average use is around 1A, there might be situations when I'll go for a few days trip ...

Is that continuous or how may hours per day ?

Assume 1A continuous for 8 hours for 5 day. That is 40AH. That is pretty small, especially if you use a cheap solar battery charger during the day. A starting battery should get you through 5-7 with a solar charger.

 

[theoldwizard1]

Dual 6V battery box

Although pretty universal, cigarette plugs and sockets are probably the WORST power connector in the world. Many (TOO many) other better choices.

 

[ncfh]

If you don't really need 75Ah all the time, give these a look...

https://www.portableuniversalpower.com/our-products/batpacs/

Has your switched voltmeter, USB power, Anderson PP 12V connectors, and very compact.

They are MUCH more portable using RBC2 or RBC4 batteries.

Need more endurance? String multiple batteries together, which the BatPacs facilitate.

And here is a guy who makes tidy single and dual battery bags for the RCB2 batteries...

https://www.amp-3.net/shop-amature-radio/single-battery-bag-bag-only

 

[theoldwizard1]

...anderson connectors for the charger hook up if you want higher amps than a cigarette lighter

Anderson Power Pole connectors. EXCELLENT, especially for high power.

Actually, some of the power connector they use on electric RC cars and airplanes are quite good, specifically Deans Plugs. They claim 50A continuous (?) ! Inexpensive, but soldering and shrink tube is required. These are well made and very small but they do not lock like the Power Pole connectors.

If you are going to buy the Power Pole connectors, buy the ratcheting crimp tool also

 

[tab2]

We use a battery box to pump out or smaller boats to move from boat to boat so we don’t have to do it by hand. Make sure to use a fuse/circuit breaker to protect your USB/other power outlets.

I would recommend Blue Sea products which are meant for the marine world and would make this very safe and easy:

https://www.bluesea.com/products/1016/Dual_USB_Charger_Socket

https://www.bluesea.com/products/5025/ST_Blade_Fuse_Block_-_6_Circuits_with_Negative_Bus_and_Cover

https://www.bluesea.com/products/4356/BelowDeck_Panel_-_15A_Circuit_Breaker_12V_Socket_2.1A_Dual_USB_Charger_Mini_Voltmeter

And ditto on the Anderson connectors to connect to a charger.

 

[RegeSullivan]

Have you considered a jumper box? They would give you most of what you are looking for in a much more compact and lighter package. It will likely be sturdier than what you propose to build, maybe even less cost overall. If the jumper box you find doesn't meet all of you connectivity needs adapters should be easy vs a scratch build.

 

[sberry]

Yes, a common jump pack, made just for this.