If you were to build a 48v Tesla module battery...

gestalt

10 kW
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Oct 19, 2009
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How would you go about charging and monitoring it?

I noticed that user okashira has Tesla modules on his website that he has retermintated for 12s instead of six. For most people on this forum I imagine that that the form factor would be a no go for them, but for me being in the giant tricycle business it’s not a problem. And the prospect of having a 48v 125ah battery on board pretty much means being able to ride all day and only have to charge at night while sleeping.

I have a pelican style black ABS case picked out but I’m at a loss for what to use for a BMS and charger that would be able to take advantage of the quick charging capabilities. It would have to have the ability to output 3000w continuous and preferably...well, almost necessity to have a Bluetooth capability in the BMS so that battery and cell voltage can be monitored in the field with a simple android phone on the handlebars instead of more wires. I suppose the output could circumvent the bms and only use it for charging.

I’m toying around with having a cycle satiator as the charger. While the watts it’s able to push out can’t really keep up with what the module can be charged at, but it would be sweet to have the charger built in to the battery case.

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image
 
gestalt said:
For most people on this forum I imagine that that the form factor would be a no go for them, but for me being in the giant tricycle business it’s not a problem. And the prospect of having a 48v 125ah battery on board pretty much means being able to ride all day and only have to charge at night while sleeping.
I have a "52v" (14s) 40Ah on my SB Cruiser trike, and can carry 100Ah on there in the seatbox if necessary (hasn't been yet), but I can see where having that much all the time would be helpful in a pedicab / etc application. It's just a lot of weight so it'll increase power usage (possibly significantly) if you have stop/start traffic or hills. My EIGs are around a pound per Ah, and I get around a mile per Ah too, at 20MPH max (~16MPH average), with the trike and me bieng more than 10x the (single 40Ah) battery weight alone.


BMS and charger that would be able to take advantage of the quick charging capabilities. It would have to have the ability to output 3000w continuous
The charger, or the BMS?

I don't know what BMS stuff is available these days, but you could use even a low-current BMS to run a higher-current contactor. Just change the shunt on teh BMS out for one taht reads the current to match the higher current you want it to trip at.

I’m toying around with having a cycle satiator as the charger. While the watts it’s able to push out can’t really keep up with what the module can be charged at, but it would be sweet to have the charger built in to the battery case.
I have a Satiator but it's only 8A max at my voltage, so for my big-pack charging I usually use Meanwell HLG series LED PSUs, cuz they're sealed like the Satiator and are CC/CV units with current limiting; the A versions are also adjustable voltage and current to fine tune them.

They weigh (and have volume) similar to the Satiator per-watt, but they come in sizes up to twice as big (600watt) and you can parallel (and series) them for faster charging. I get about 12A from a single HLG-600-54A, and about 24A from two in parallel.
 
amberwolf said:
It's just a lot of weight so it'll increase power usage (possibly significantly) if you have stop/start traffic or hills.

The nice thing about these modules is that they are obscenely light for the capacity, they come it at 55lbs and the case I’m planning on using weighs 10lbs. So at a total 65lbs on a trike that weighs 150lbs before I add myself, motor and sometimes over 1,000lbs of passengers it is a drop in the bucket.

I’m going to look into those meanwells, even one would be great. The end goal is to have one unmodified module running a 5000w inverter that trickle charges all day long to quick charge the 48v pack to 80% in one hour while I’m taking the evening break. I guess I would quite a lot of them to get the needed 5000w to do that....hmm.

Well one or two in the meantime would do the trick.
 
Proably not: he does pedicab stuff up in Boston. ;)

(I usually only have about 250-270lbs of passengers, not counting myself, but I've carried almost 600lbs of stuff in one load, part on the trike and the rest on the trailer)
 
Hillhater said:
:shock: :shock: :shock:
I hope that is a typo ?

What’s really going to bake your noodle is that I did it for many years no motor. I’ve def done the 1,000 uphill no motor, more on the flats just my quads...er...octos.
 
Build to the application, and it works fine.

I'm actually using regular recycled bicycle wheels on my trailer that I haul the dogs and dogfood with, and they've survived it so far, but it's only about half the load the pedicabs he's talking about see, and are not doing it all day long day after day. I just make sure they're well-tensioned (by eye/ear/feel, no tensiometer; could do it better with one I'm sure), and true and round.

There's much better rims and hubs and axles to use for these kinds of loads, but regular bicycle spokes (good ones) still work.

One could build heavy motorcycle wheels for these things, but it's probably not needed in most cases, and is just extra weight (several times that of a bicycle-class wheel). The main reason to go to one would be if you need the MC-type tires for flat protection or wear time, I'd venture.


FWIW, Chalo builds pedicabs and wheels for them, too, which is one good reason to follow his advice on wheelbuilding. ;) If they work for that application, they'll survive most anything else you throw at them.


Brakes...it depends on the speeds you go. Faster = more energy to dissipate, so if you aren't going that fast with these kinds of loads, it's not that much worse than going fast with a lesser load.

I have cheap rim brakes on the front (two sets) and hubmotors with regen/EABS on the back and it stops the trike with hundreds of pounds in it, albeit not as quickly as I'd like.

If I had really good brakes on all the wheels, I'm sure it'd work fine, and that's probably what these pedicabs have on them.
 
amberwolf said:
FWIW, Chalo builds pedicabs and wheels for them, too, which is one good reason to follow his advice on wheelbuilding. ;) If they work for that application, they'll survive most anything else you throw at them.

Who do you think is building my new wheel set?

Perks of moving to Austin.
 
Go with the 300 amp Bluetooth bms from China and the chargery 25 amp offboard charger.
ElectricGod is testing similar bms now.

lto-bms1 - Copy.gif
 
gestalt said:
Perks of moving to Austin.
You should probably update your profile. ;) (still has you as a noreaster)
 
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