Harden Electric Blog What we have been working on update 17MAY20

What we have been working on update 17MAY20

They say there’s no rest for the wicked, and less than 24 hours out of a major knee surgery I just couldn’t sit on the couch any longer, but, in my post-surgery couldn’t sleep state, I realised there’s something we can do to help people electrify their futures, and that the answer doesn’t always lay entirely in automotive electrification. People still love to use their cars for all manner of things, like boating, camping, fishing, adventuring, touring, or even just to run a fridge to keep all the beers cold.

However there aren’t a great deal of rugged, reliable, lithium setups on the market. Either you have one really big stonking expensive battery, or a bunch of smaller ones with no BMS that you have to link together in a “dumb” fashion, and this kind of setup will always be dragged down by the lowest cell in the pack. So if you have 5 batteries, all supposed to be at 12.8v, however one of them dies on you and drops to 11.5v, your entire pack will get dragged down to that. Basically, the bad battery will drag the others to his level and beat them with experience. Not a good way to go.

So, although it isn’t perfect, we would like to show you our newest creation down this path, something that is useful for everyone, a camping battery that you can make at home with a sheet metal bender, a riv-nut gun, and some crimping tools. If you don’t have a sheet metal bender, a flat bench edge and a hammer should suffice.

If you will note, there are seams around the edge, it’s a bit harder to stack some dimes along those edges in CAD, however all those seams should be welded up once assembled to help prevent water ingress. Though if you’re not worried about that, then you can leave the gaps if water ingress is not a concern in your application.

So for this project, we have used the Winston WB-LYP200AHA battery.

This is a 200AH Battery delivering 3.2V per cell, so can be banked in series to get 12.8V once connected.

The dimensions of the batteries are 55 x 360 x 255mm making them reasonably compact and energy dense for this application.

Weighing in at 8kg each, a simple 12v system will net you around 32kg of batteries, so not overly heavy.

The sheet metal is 3mm thick stainles steel, intent is to spot weld the flanges and then seam weld the exterior edges for prevention of liquid ingress.

We are using stainless steel M6x1 Stainless Steel Rivnuts for security between the top and bottom boxes.

BMS Specced is an Orion BMS Jr. If you want to use the CAD Model, we would suggest you go and look at the model at this page created by the awesome jigg007 over on GrabCad.

Applications for this unit could be:
-High Draw winching operations to help take the load off your starting battery
-Run the fridge to keep the beers cold
-Run solar lights in your camper

The adaptability and longevity of Lithium batteries is also a huge bonus in this area, due to their energy density and ability to provide long lasting reliable service to the user means that they are a great investment. Also, like most vehicle parts used in applications such as this, they can be transplanted from vehicle to vehicle as you upgrade throughout the years, so that initial investment is not a permanent addition to your vehicle, you can always take it with you as you move between vehicles.

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