Camping 24p4s 16.8v pack

Darmok

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Feb 18, 2017
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This is a side project from my 140p14s power wall project. This one is for camping power. Thought I'd put it up here.

Main use is power for ; camp lighting, power supply for 12-24v Engle fridge, 12v MinKota electric outboard motor for canoe and handheld device charging of phones cameras and torches.
Pack runs a Minkota 35 12v outboard for just on an hour on max throttle 5 which draws approx 30A
Each cell in the pack is 2300mah min capacity

Prototype unit is in a Pelican case and uses the 4 slot holders soldered back to back in 4s arrangement.

There is no cell Protection other Han what is arch cell has.

Charging at this stage is done by a hobby charger. I need a solar charger that can handle 50v in and programmable 16.8 out, Any suggestions?? I've tried the MPT 7210-A but it doesn't like that variance in input and battery voltage.

Connection is 50A Anderson plug and a 4s type balance lead.

Pictures show some fuses I had in for testing which have since been removed and unit now only has one fuse on while pack.

Pack is obviously a bit risky without cell fusing. Using these 4 slot ABS Battery box type of cell holders is risky with the end terminals able to cut through the end insulation and short the cell. Cells only go in and out negative terminal first.
Cells must all have very good condition wraps.


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SimonW

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Aug 26, 2017
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Darmok said:
....
Using these 4 slot ABS Battery box type of cell holders is risky with the end terminals able to cut through the end insulation and short the cell.
....

Looking good. Like the pelican case idea for when you're out on the water.
Don't like the sound of those holders, any reason you didn't use 4x5's?

What is the temp like in that sealed case when drawing 35A?
 

Darmok

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Feb 18, 2017
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Warm but not hot. Real world it won't be on 30-35A that long.

I'm getting over soldering and to finish the main power wall I've got a bit left to do. The ABS type are a lot less soldering compared to the modular type 4x5's and incredibly easy to change out cells if needed. Plus you can get more cells in which means more capacity.

I love the case it's awesome. I plan on making about 6 of these things fir myself and friends.
 

SimonW

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Aug 26, 2017
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Darmok said:
... and incredibly easy to change out cells if needed.

Makes sense for maintenance.
They sure fill thecase efficiently, it's like Pelican designedthat case with the ABSholders in mind! :D
 

DarkRaven

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Sep 2, 2017
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They make these things in many different sizes I guess, we should check if the bigger ones have the right dimensions as well! :)

I like what you have done there, I want to do something like that as well in the future. Also got some of these holders to try and see if they would be useful, you have beaten me to it :)
 

Darmok

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Feb 18, 2017
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My shed is chaos, I got lots of projects on the the go. The challenge is to get some done.

The "camp battery" as I call it needs a nice cheap BMS that also protects from over/under discharge. I'm still trying to test the one that's been linked in these forums before. I'd also settle for an adjustable low voltage cutoff.
 

DarkRaven

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Darmok said:
My shed is chaos, I got lots of projects on the the go. The challenge is to get some done.

That sounds very familiar!

Can't you do the voltage control manually? I guess when you are camping you don't have the battery running while it is unattended?
 

jdeadman

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Mar 28, 2017
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the 7210a is a boost charge controller it needs the panels lower than the battery. you might have to go as far as a MPPSolar or Something bigger to charge at those input voltages. make sure to have some sort of BMS For nothing else than information on where your pack is. For my lawnmower pack and other small projects I use https://www.amazon.com/EDEALLINE-Meter-7-Digital-Capacity-Controller/dp/B00AKR8V9K

This balances (really slowly) but also will tell you things like total pack voltage, difference in voltage between cells, max and min cells, as well as in balance mode reads out each cell voltage.


https://www.aliexpress.com/item/60A...815256522.html?spm=2114.search0302.4.6.qctJqr

this is user settable voltages
 

Darmok

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Feb 18, 2017
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The plan is to have a few of these "camp batteries" and be able to daisy chain them up for added capacity. Have some at the campsite running the camp LED lighting and fridge, getting charged off a couple of recycled large solar panels. These are tricky to use in this application because of their high VOC. which is between 40 (60 cell) and 55v (70 cell). But can be bought here in Western Australia for $25 for a 6 year old 180w mono which outputs 6amps.
Rotate packs between the canoe and camp for day trips which will have a couple of panels on it as sun shade and to charge the "camp battery" to extend runtime.
So the battery in camp needs some protection as it could be left unattended for up to 10 hrs.
 

jdeadman

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Do you have a link or manual for those batteries. I'd like to have a look at how they are setup
 

jdeadman

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Mar 28, 2017
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Wow This goes Back a while. I have no idea what I was asking so I went through the thread and I think I was about the holders on the bottom of the case???? Sorry that was like 8 months ago lol
 

Ciaranm81

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Apr 28, 2018
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hi,an epever mppt charge controller can be programmed to any voltage in the 12-24v range. i have been using the 40A version with a 260w 60 cell panel for 2 years with no issues. You can also get a bluetooth module so u can monitor on your phone i have one for my camping setup and swear by it. you can program the cutoff voltage aswell to suit 18650's. the 40A version is usually about $180 on ebay
 
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