Battery pack

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Bruce D
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Battery pack

Unread post by Bruce D »

My old Duracell 28 AH battery pack let me down at Stellafane- I had used it around the house a few times over the last 6 months and it seemed fine, but once it started running the laptop and the mount and camera it was dead in 30 minutes. I can't complain, I've had it for about 20 years.

I've decided to build my own battery pack, going lithium. I have two 10 AH batteries that I switch out to run the electronics on my kayak, I plan to get two more to give me a total of 40 AH- more than 50% greater capacity than my old Duracell (which would get me through 3 nights of observing- but that was pre-ZWO camera) so I should be set for extended weekends (also, they charge much quicker than lead/acid batteries).

I want several 12 V outlets- I'm thinking the cigarette lighter plugs aren't the best, sometimes they wiggle interupting power, necessitating re-aligning the mount. I am considering using jacks and plugs, maybe even the screw-on style that Celestron uses for their power cords. Jacks would also take up a lot less space on the panel. Comments?

Several USB outlets- I haven't looked into how these work- do they have an internal voltage regulator that drops 12 V to 5 V? Or do I need to build in a regulator? I'll have to check into that.

A couple of 120 V AC outlets. I'd rather not use the old style power-robbing type with the fan and the huge heat sink- maybe there's a solid state version these days? I MIGHT be able to dissect the AC portion out of the old Duracell powerpack which would make everything easier, 200 watt output should be plenty for the laptop.

Maybe a voltmeter to monitor the batteries?

A couple switches and indicator lights

Am I missing anything?
Bruce D
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Pete
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Re: Battery pack

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That's a very complicated setup Bruce. Wonder why there's nothing like this commercially available.....
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Paul D
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Re: Battery pack

Unread post by Paul D »

Simple build, made this one myself and probably will make a larger one soon. This was based on photos I saw online. Figured I would start small and get the wiring down before I attempted a larger version. The box is a plastic ammo box with a water proof rubber seal in the cover, but the future build will be a plastic tool box. I have two USB plugs under the Voltmeter cap.


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Paul...

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Pete
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Re: Battery pack

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That's a really sweet setup Paul.
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Bruce D
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Re: Battery pack

Unread post by Bruce D »

They do still have commercial units, but for 20 AH you are looking at close to $300 and that's probablya sealed lead/acid battery. I've already got half the LiPo batteries I need and that's where the large majority of the expense is. Plenty of hobby electronics experience when I was young, I just hope to avoid the old "oh gee I wish I had thought of that before I built it" routine
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Pete
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Re: Battery pack

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Radio Shack. Sigh... The good old days.
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Bruce D
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Re: Battery pack

Unread post by Bruce D »

Agreed Pete, it was awesome having such a supply outlet so readily available. You-Do-It in Needham is far more well stocked, but Needham is a hike. I grew up a few miles from there and have fond memories of riding there on my bike with friends to look over all the cool stuff and buy components for our projects. Lots of stuff is available online but you have to know what you want.

It looks like the USB ports will be simple- I've been reading that a lot of people are adding them to their cars and they sell them at the autozone etc., just supply them with 12 V DC and they are ready to go. Maybe a couple of charging ports in the sidecar would be cool. Eh, maybe that's 6 V I'm guessing.
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mrgizmo65
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Re: Battery pack

Unread post by mrgizmo65 »

Hi Bruce, you do it boy that's a place I remember well. When have you been there last??The only reason I ask is I think you may get sticker shock on the cost of items there now .I am interested in how you start your build.. Paul's pictures of his build was super neat and some of the components he used look like they were made for the box he used. Nice,neat,and simple. Good luck on your project!! Jerry :mrgreen:
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Bruce D
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Re: Battery pack

Unread post by Bruce D »

Hi Jerry, I've been to You-Do-it in the last couple years, I installed navigation lights and navionic systems in my kayak so I drove up to Needham looking for components, mainly waterproof switches and relays. Yeah, their prices have gone up, and now they cater more towards the professionals and much less to the hobbyist but they still have a huge selection of components and project supplies on hand. I could probably get everything online but I like to stop in there every few years out of a sense of nostalgia I guess. First things first when the other 2 batteries come I can decide the best way to arrange them and that will determine what size/shape box I need. I don't have a lot of interest in building the physical case, I hope to use something off the shelf, probably some manner of tool box.
Bruce D
Bruce D
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Re: Battery pack

Unread post by Bruce D »

This is the case I keep my fly tying tools and materials in, something like this but smaller would be perfect, plenty of storage for a multimeter, wire strippers spare jacks and other parts and it has a big sturdy handle. If I can find one about half this size would work.
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