Andrew -Cells looks good for a 6P setup. Have you found a discharge curve for this cell at 5A? Glad to see you go for 6P instead of 4P Happy to go over your shopping list for bibs and bobs you will need. Cheers
Shaping up the plywood 'spacer' at the moment, should have it moulded, glued & sanded for the weekend. Still checking the post everyday for my torqueboards stuff. Where did you snap up your fuses from? They look similar to the ones that come with the gen2 boards. Shopping List:
Laminating the plywood for the battery enclosure spacer. Will only be about 1 inch of ply all round, edges bevelled to match the enclosure. Will post the finished product. {}
Yep, but looking at a few different builds the overall thickness could be +/- depending on where I run the battery cables? Might still need a spacer/rubber between the timber & board. Cells -> Purchased! Your 80km time travelling machine was the kicker to start getting things done!
Andrew - I used car fuseholder and 40A fuses - and have blown a few through shorts etc Cheers 10pcs Standard Blade Fuse Holder Splash Proof 40A DC 32V Cable In Line Car Auto | eBay
Thinking about whether to build the pack 'square' (cells perfectly on top of each other) or staggered (2nd layer sits in the 'grooves')... Staggered would be more solid, less air gaps, maybe run hotter?.. Not sure where I'd position the nickel strips to make the 'fold' if I positioned the cells staggered? (apologies for the shadow in the photo) {}
Motors arrived! Have come with a AG MT-30 plug unfortunately, so will need to give that the chop and replace with individual bullet connectors to plug into each VESC wire.
Andrew - I went for removing the very heavy wire and bullet connectors from vesc and using a lighter wire (14awg silicon flex) and a female MT-30 plug on vesc . The large bullet connectors are far too large for the max motor current ( approx. 35A) and will occupy too much room inside enclosure. Also - changing over to MT-30 means any evolve or racestar motor can easily drop in as a replacement -if required.
Andrew A key decision for battery configuration is either Option 1 or Option 2 as per sketch. I went for option 2 . Option 1 requires multitude of connections between the two halves ( the fold) using multi layer nickel strips . For current carrying capacity in your 6P pack - you will need at least four 10mm 0.15mm nickel strips here and I think there would be mechanical issues trying to fold the strips ( different bend radiuses on the four strips causing mechanical stress etc.) . Option 2 has the inter-cell connections as a flat connection (with no nickel strip folds) and dual flexible copper braids can be used for good current sharing inter-cell connection and this will provide good flex ability between the cell packs( see my blog pictures) - however Option 2 has voltage differences along the inside of the two pack halves. I put liquid tape and double layer of rubber insulation between the two pack halves to mitigate any issues. My suggestion for cell insulation simplicity , maximise flex handling and minimise any future inter-cell connection issues is to go with the double layer cells directly on top of each other with Option 2 {}
This is what I'm weighing up at the moment... making something similar to the whitepony battery on endless sphere, but using 3x2 cell blocks and still attempting the 'fold' down the middle.. or going with option 2. I didn't think the 'fold' would require multiple thickness layers of nickel? I think i'll be saving the trouble for sure of 'staggering' the layers, only saves a few millimetres thickness there. Got my notification of cells having been despatched so waiting for them in mail, then should all be here.
Andrew - Not sure what nickel strips you are getting but 10mm x .15 has about 5A rating at best. The folds will take full battery discharge current ( up to about 70A for full load for your two 140kV motors ) and you don't want the nickel strip over-heating or volt drop under high load demand.( this will cause voltage sag and loss of torque) For your 6P 3x2 pack - for the series connections- you want at least two parallel current paths for good current sharing amongst the 6 cells in parallel. Something to consider. If you go with a centre fold system - I would think the minimum would be four strips in parallel which you may be able to do along the length of a three cell long pack. These could possibly be single strips but better for each to be double strips . Best bet is to get your nickel strip and experiment a bit before you start on cell pack construction. {} {} .
i' i'll find a handy sketch-up tool and draw what i'm thinking of. was going to do a series connection for each battery within the 3x2, so would be 3. Could be reinforced with the copper braid? I see what you mean about doubling that and then trying to get a radius, something would break. Any updates on your beast or still smooth sailing?
Still in their packets, I'm powerless (!).. Motormount screws ordered also the wrong size.. turns out the DIY route takes much longer than anticipated.
Had another think about the 2 layouts Roger, option 1 provided the 'channel' for the positive/neg wires, but in option 2's layout, you wouldn't need the channel anyway as both 0 & 42v wires are at the same end? What sort of material/foam/insulation would you recommend down the centre of the option 2 setup?
{} {} Option 2 with a bit of a re-configure.. I think this is how 'Long Haired Boy' builds his? Only queries on this: - he seems to rely the balance wires + hot glue to add some insulation down the centre, I'd be more comfortable with a foam or something similar to prevent the short? - Is the copper braid required over the nickel? He looks to go without it.. - Does the battery indicator / fuel gauge just wire into this setup? {}
{} [QUOTE=" What sort of material/foam/insulation would you recommend down the centre of the option 2 setup?[/QUOTE] I used a four phased plan 1) Use fibre tape to wrap cell packs end to end leaving only flexible braids exposed 2) On flexible braids - apply liberal amount of liquid insulting tape ( red on photos) 3) On flexible braid areas - a separate piece of rubber foam strip ( from Clark Rubber - see my materials list) over each inter-cell area 4) Another piece of rubber foam strip running the whole length of the pack - more a piece of mind requirement Any short along the pack inside connections will destroy the complete pack and probably catch fire as the main fuse will not see this current {} {} {}
