Several things need to be considered when designing a Custom Motorcycle building a battery box.
- Size – to allow battery to fit
- Shape – for battery fit and also where on the bike it will fit
- Mounting method / position e.g. brackets, flanges, bolt fixing, welded to frame, removable.
- Will it sit snug in its space and be fixed strongly enough – as a battery can weigh a good bit.
- Will it interfere / hit / affect operation of / with other components e.g. gearbox, carbs / throttle bodies, side panels, seat, rear panel, electrics etc.
- Can you access the battery terminals easily should you need to?
- Consider mounting and positioning so that terminals do not touch or foul and arc onto another metal part of the motorcycle.
- Drain, in case battery leaks.
- Battery is held in position / fixed by clamps, rubber straps etc.
- Do fuses need to be located or relays on the battery box or near to it – is there room for them and fixings to hold them in place?
All these things may be a simple point to note but if you are building a battery box in what ever material you do not want to find that after you have spent good time and money it will not fit and be secured in the designated area.
When we deal with customer requests for battery boxes or trays for cars or motorcycles we very often ask – “have you made a cardboard mock up of what you want to check that it will fit ok”?
Inevitably if not there can be issues of the manufactured box or tray not fitting correctly, hitting or fouling on other components, difficulty locating it, rubbing or damaging frameworks (especially after you have paid a lot of money for a paint job) during fitting etc etc. For a small amount of time messing about with scissors, cardboard & sellotape you can save yourself both time, money and grief.
Battery Tray Customer Drawing
Anyway we recently received this drawing from the customer and had a couple of emails and phone calls to clarify things and make sure he got what he wanted and we could manufacture as a 1 off item at the most economical cost.
One or two bits were redesigned and we ended up with an easier slightly cheaper item to manufacture which was good for all involved.
Once all happy we proceeded to manufacture parts to make up the battery box from stainless steel, this was going to be mirror polished and so during marking out (using scribe, rule, square), cutting out (using guillotine & cutting disc) we needed to be very careful not to mark the surface.
We used Stainless Steel 304 grade, PC1 – Plastic Coated 1 side, 1.5mm thick, the idea is the plastic coating provides resistance to marking etc during manufacture, we have also in the past covered the whole surface in masking tape to prevent marking. Once all the parts had been marked out, cut out and folded where required it was time to tack weld and assemble all the parts –
Parts ready for Assembly, edges pre polished
Before tacking the parts together we made sure that the edges were pre polished – this makes it far easier when final polishing the parts after assembly and welding. 
Tack Welded Panels
As you can see in the above 2 images, “tack up” and “set up” is critical in getting any job right 1st time, It is worth spending a few minutes more at these stages as if not it will take a lot longer to sort out the consequences at a later stage.
For example if the job is tacked up out of square and then welded up you would have to cut out all the welds to be able to get the job squared up properly, time consuming, messy and it will never be the same. If you tack up a joint out of level for example you can get a larger gap one end compared to the other and this may affect the size of the weld where you have welded along and then found you have to lay a larger fillet to “fill” the gap, this can also increase risk of distortion and penetration through the joint, both of which may cause problems later.
So the idea when cutting and forming this job was to make sure that we got our panels sized correctly so that we could achieve a neat corner corner joint at the tack up stage between panels. see B below !
If the joint was not quite set to a corner joint we simply closed down the tack using a small Pin Hammer, this is sufficient for closing the gap down as minimal effort and “weight” is need to do this.
When all parts are tacked together and the joints are all neat closed down corner joints this will be ideal for a neat bead of weld along them, after checking the job for square again.
Fuse Welded Joint
As we achieved a good set up of the joints we were able to “fuse weld” them together, this is a method where as no filler wire is added to the molten pool of weld, the edges of the material are simply melted together as we run along the joint. If you are an experienced welder you can set up your machine to achieve this easily as long as you get your rate of travel along the joint correct. If not then you will get a build up of localised heat and excess penetration and in some cases a nice hole in the joint just where you dont want it.
I completed the welding of this job by using the TIG welding process which for this kind of job is ideal as it is a very “neat” and “precise” method of welding when compared to MIG welding .
Polished Battery Box
Using the TIG welding “fusion” welding method I was able to mirror polish the complete job without sanding or blending in the welds as these were “smooth and flush” to the material and looked neat and tidy as they were “laid”.
Unfortunately for me my motor on my polisher died a death whilst trying to finish polishing this job and I had to polish by sander and hand – this took me 3 times as long and still ended up not quite 100% up to my standards. As several sides of the battery box will not be seen when in situ it should be fine though once fitted.
4.5 inch grinder with polishing attachments
For all your Custom Car & Motorcycle Parts Manufacture and Welding / Repairs
SEE –
www.flashcustoms.co.uk
Don`t forget to email or call us for all your custom made 1 off bespoke items.
Thanks for reading our blog – we hope this has been of use to you.
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