LiFeYPo4 questions

[Sunking]

Actually, what I'd like to do is fly Sunking out to the U.K. to collaborate with Burgerman on this (actual pics w/lifepo4):

http://www.wheelchairdriver.com/BM-MK3-lithium-fast-powerchair.htm

Slightly off topic, but hopefully inspiring to the various uses we can put this technology to.

Me doeno 15 mph in a wheelchair just sounds so wrong

[PNjunction]

Actually, what I'd like to do is fly Sunking out to the U.K. to collaborate with Burgerman on this (actual pics w/lifepo4):

http://www.wheelchairdriver.com/BM-MK3-lithium-fast-powerchair.htm

Slightly off topic, but hopefully inspiring to the various uses we can put this technology to.

[reed cundiff]

PNJunction

Thanks for getting thread back on topic
Reed

[PNjunction]

I wonder how many LSV'ers don't even golf?

These guys using lifepo4 don't. See the "step by step lithium conversion thread". They have long graduated past the Odyssey-powered chairs.

http://www.wheelchairdriver.com/board/viewforum.php?f=2&sid=d1f024b21b57e00e0897b00ffa81e6d2

Their application actually discourages using large prismatics, and favors the much higher-rate high-capacity cylindricals. Roboteq controllers, high-tech motors, wheels, powder-coated custom frames, Hyperion chargers - you name it - non-commercial site with nothing for sale.

Burgerman provides this all on his own to basically show the sorry-ass state of affairs when it comes to wheelchair tech - stuck at the turn of the last century for the most part.

I'd call these guys "msv" or medium speed vehicles now, although Burgerman's racing chair does have functional wheelie bars.

[J.P.M.]

How did you know what my Club's requirements are to join? That can only mean you are a Card Carrying Red Neck.

I was sort of brought up that way when very young and have a good memory for when things were simple(r) and people straighter. Learned to take responsibilities and job seriously - and myself not too much so. Been in Redneck recovery for a long time, but the roots run deep and relapses as below sneak out every so often. Enough of this - I've got to go sharpen my head.

[Sunking]

Shootin' critters and par using the same vehicle - now THAT'S a cost effective use of resources if I ever saw one. Does your club allow you to strap a deer to the hood ? Weapons in the golf bag ? Are tree stand golf shots allowed with a club, or are you limited to a slingshot ? Are you required to yell "FORE" before touching off a round ? Limit hunting parties to less than 4 ? Golfer safety courses required ? Can you still use such a vehicle on a posted course ? How do you muffle the club jostle noise in rough terrain ? Or does that noise sound like clashing antlers in rutting season ? Is a back window required for the gun rack ? Can you bring down a deer with a Titleist ? Is there a taxidermist in the pro shop ? Lots of details to consider. I'm just wonderin', ya know ?

How did you know what my Club's requirements are to join? That can only mean you are a Card Carrying Red Neck.

[Sunking]

Well here is the meet on the bone. Your standard Big Three golf cart manufactures carts curb weight is 980 pounds on the light side and up to 1030 pounds so let's just say 1000 pounds. Of that 1000 pounds is 500 pounds of battery, lead acid batteries or 48 @ 170 AH. A LFP 16S 150 AH pack weighs 113 pounds. You loose 400 pounds or 40% of the vehicle weight, and gain performance and usable capacity. The object is to get to at least 35 mph, and dumping 400 pounds goes a long way to assist in that goal. So for me it is a win-win-lose. The lose or what is lost is about $2100 battery, compared to a FLA cost of roughly $750 to $800.

Ask any Knuckle Head, Grease Monkey, or Motor Head fast ain't cheap.

[J.P.M.]

Rednecks like myself also use them for Hunting Buggies.

Shootin' critters and par using the same vehicle - now THAT'S a cost effective use of resources if I ever saw one. Does your club allow you to strap a deer to the hood ? Weapons in the golf bag ? Are tree stand golf shots allowed with a club, or are you limited to a slingshot ? Are you required to yell "FORE" before touching off a round ? Limit hunting parties to less than 4 ? Golfer safety courses required ? Can you still use such a vehicle on a posted course ? How do you muffle the club jostle noise in rough terrain ? Or does that noise sound like clashing antlers in rutting season ? Is a back window required for the gun rack ? Can you bring down a deer with a Titleist ? Is there a taxidermist in the pro shop ? Lots of details to consider. I'm just wonderin', ya know ?

[inetdog]

Rednecks like myself also use them for Hunting Buggies.

Heard a great one today:
"The best form of gun control is using two hands."

[Sunking]

I wonder how many LSV'ers don't even golf?

Rednecks like myself also use them for Hunting Buggies.

[inetdog]

Well if you are asking me, for a Low Speed Vehicle. You know golf cart V3

Right, but I have not intention of doing that.
I wonder how many LSV'ers don't even golf?

[Sunking]

"What would you do with them?"

Well if you are asking me, for a Low Speed Vehicle. You know golf cart V3

[inetdog]

Having said all that I do like very much the new design with four-point intercell and terminal post, integrated safety covers molded to accept BMS wiring and hardware, and all the hardware and packages available. They make great buildin gblocks and you can by them pre-fabricated from stock selections or Turn- Key to your specs. I am looking at either a 48 (16S) or 60 volt (20S) 100 AH block for the LSV. Most likely 48 volt due to budget. Speed cost big bucks.

"I wish I had enough money to buy a bank of batteries like that."
"What would you do with them?"
"Oh, I wouldn't actually buy them, I just wish I had that much money."

[Sunking]

the now famous square terminal connectors each with 4 bolts instead of just one. This lessens the chance for a loose terminal going high-resistance. For EV'ers with many many multiples of cells, that can be a pita to check, but should be done nevertheless.

With other quality cells like CALB, they typically only have one bolt per terminal, which of course needs to be properly torqued. To maintain that torque under high-vibration environments like an EV, nord-lock washers are usually favored and may not come with the battery.

To avoid sounding like a salesman trying to pit one approach against another, both approaches are good for ensuring a tight connection.

Gotta strongly disagree here as a engineer. Two or more points is far superior to any single point like a ring type connector using only one bolt. Mechanically and electrically no contest.

On the mechanical side you can take apart any electrical connection without tools, only using your bare hands by using the leverage of the compression barrel. Even gravity over time can loosen a connection when installed on a vertical plane. Secondly single point has less contact area.

Two point tor more cannot be leveraged off, and provides greater surface area with higher pressures thus making lower resistance connections. This becomes real important on high current connections.

This is a detail that is often the difference between consumer grade electrical products and commercial/industrial grade electrical.

Having said all that I do like very much the new design with four-point intercell and terminal post, integrated safety covers molded to accept BMS wiring and hardware, and all the hardware and packages available. They make great buildin gblocks and you can by them pre-fabricated from stock selections or Turn- Key to your specs. I am looking at either a 48 (16S) or 60 volt (20S) 100 AH block for the LSV. Most likely 48 volt due to budget. Speed cost big bucks.

[PNjunction]

KEEP those connections properly torqued!

I forgot to say I'm glad Sunking brought mentioned the appearance of the newer generation of GBS cells.

Years ago the chemical formulation was improved, but it also did something more - the now famous square terminal connectors each with 4 bolts instead of just one. This lessens the chance for a loose terminal going high-resistance. For EV'ers with many many multiples of cells, that can be a pita to check, but should be done nevertheless.

With other quality cells like CALB, they typically only have one bolt per terminal, which of course needs to be properly torqued. To maintain that torque under high-vibration environments like an EV, nord-lock washers are usually favored and may not come with the battery.

To avoid sounding like a salesman trying to pit one approach against another, both approaches are good for ensuring a tight connection.

No matter what the chemistry, be it lead or lifepo4, bad connections and sloppy construction or wiring has to be avoided at all costs. In some cases, the poor performance or dramatic failure events reported by the media are attributable to this, and not the battery itself per se.