Left the ballance connector just enough to plug in the CellLog..
Replacing Skidoo 12v SLA with LiFePo4
- Thread starter Ypedal
- Start date
liveforphysics
100 TW
Nicely done. 
For folks wanting a little more capacity, and a lot less work (just connecting the leads up), you can buy this pack:
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14074
It's 4s of 30C 8.4Ah LiFePO4 all ready assembled into something you could simply connect the leads up where a lead-acid 12v battery goes.
For folks wanting a little more capacity, and a lot less work (just connecting the leads up), you can buy this pack:
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14074
It's 4s of 30C 8.4Ah LiFePO4 all ready assembled into something you could simply connect the leads up where a lead-acid 12v battery goes.
Damn.. that woulda saved a bunch of work.. Would still have had to box it up into something solid, the guy using this pack likes to climb insane stuff, i'm told the sled ends up on the handlebars at times to prevent it from barrel rolling down the hills when the climb don't happen as planned lol... i'm confident this pack will hold up..
Ok, next part i need a bit of help with is the Vicor DC DC thing...
quote Dr Bass "... ... ... connect the trig Out to the positive input. Also you need to connect the S+ to the positove out and the S- to the negative out. .. "
I found the spec sheet;
http://cdn.vicorpower.com/documents/datasheets/ds_vi-j00.pdf
Unfortunately i suck at this stuff, can someone ms paint for dummies this for me ?
12v from the pack on + IN and - IN
I get 3.3v from the + OUT and - OUT
But " Trig out to positive output " i see no trig.. but i do have Trim ? :lol:
Ok, next part i need a bit of help with is the Vicor DC DC thing...
quote Dr Bass "... ... ... connect the trig Out to the positive input. Also you need to connect the S+ to the positove out and the S- to the negative out. .. "
I found the spec sheet;
http://cdn.vicorpower.com/documents/datasheets/ds_vi-j00.pdf
Unfortunately i suck at this stuff, can someone ms paint for dummies this for me ?
12v from the pack on + IN and - IN
I get 3.3v from the + OUT and - OUT
But " Trig out to positive output " i see no trig.. but i do have Trim ? :lol:
liveforphysics
100 TW
You have 4 of those vicors for this pack right?
I think he wants to put one in series with the 12v battery to boost it.
Yes, I think Doc meant Trim. If 3.3v is what you want, you can forget the trim. The trim will allow some adjustment to the voltage if needed. The trim is fed by a pot or pair of resistors coming off the output pins.
I think this is the simplest setup. Keep in mind the dc-dc sucks a lot of power whenever it is hooked up to the 12v battery, so put the switch on the battery side.
NOTE: I flipped the Vicor upside down in my picture to put + on top (don't ask me why).
Also, I'm not sure about the gate in/out pins. On most Vicors, you need to feed power to one of those pins to make it turn on. I think on some you ground the pin. Maybe somebody else knows which way it goes on this one. You could poke around with a 1k resistor between the gate in and either ground or 12v and see what it does. If you're lucky, it will just run with nothing on the gate pin.
Yes, I think Doc meant Trim. If 3.3v is what you want, you can forget the trim. The trim will allow some adjustment to the voltage if needed. The trim is fed by a pot or pair of resistors coming off the output pins.
I think this is the simplest setup. Keep in mind the dc-dc sucks a lot of power whenever it is hooked up to the 12v battery, so put the switch on the battery side.
NOTE: I flipped the Vicor upside down in my picture to put + on top (don't ask me why).
Also, I'm not sure about the gate in/out pins. On most Vicors, you need to feed power to one of those pins to make it turn on. I think on some you ground the pin. Maybe somebody else knows which way it goes on this one. You could poke around with a 1k resistor between the gate in and either ground or 12v and see what it does. If you're lucky, it will just run with nothing on the gate pin.
Thank you !!!!....
My rats nest test :
My rats nest test :
direct from 4 lifepo4 cells ( 13v )
with the DC DC unit in seris with the 12v pack = 16v
and for comparison, 48v
Not much of a noticable different from those pictures, ( holding camera in my hands between tests, moving slightly each time... )
But at 13v there is a noticable loss of output difference by eye..
Not much of a noticable different from those pictures, ( holding camera in my hands between tests, moving slightly each time... )
But at 13v there is a noticable loss of output difference by eye..
trappermike
100 W
Ypedal,you can easily(and cheaply) add some warmers to the battery pack if you need to.
Skidoo sells a "Heated handgrip" kit as an accessory,it is basically 2 thin stick-on heating pads that are supposed to go under your handlebar grips,but could be put on the battery pack,and comes with an on/off switch too. Very simple to install.
Skidoo sells a "Heated handgrip" kit as an accessory,it is basically 2 thin stick-on heating pads that are supposed to go under your handlebar grips,but could be put on the battery pack,and comes with an on/off switch too. Very simple to install.
trappermike said:
I actually have a set of those already !! i had a polaris ATV last year and got a set on ebay, they accidentally sent me 2 sets so i have a spare !! lol..
But, i dont think it's going to be a problem, the hardest start will be the initial cold start and after that the machine will produce enough ( possibly too much ) heat to keep the pack toasty.. and it has pull start backup ..just in case ! lol..
My friend came over last night and we wired it up, i installed anderson PP75's on the pack, and i made a pigtail for the machine with matching andersons. so the original battery could easily be put back in without any permanent mods to the machine.
We fired it up, no problem at all, with the celllog connected voltage dropped to 2.9v per cell and quickly back to 3.300 as soon as the motor kicked in, revving up the motor brings them to 3.4~3.5 and when the rpm's settle down to idle it's 3.3v so far so good..
The true test will be an extended run up the trail, and i should have more data at that point.
Also wired up the DC DC unit, tested the light, all good.. he will weld a tab on the hand protectors to bolt the light onto.. and that's that ! 8)
Update, earlier in the week i spoke with J. ( skidoo owner.. ) and at -15 celcius the pack could not turn the motor over, had to pull start and ran for 10 minutes, then it worked.. I also asked if he wussied it and only tapped the button, but he confirms that the Go button was pushed repeatedly and for duration.. so that's that.
The Cycle Lumenator was also bolted on,
Pictures were taken with a blackberry, and with freezing hands so image quality is not ideal, still shows the difference, this is with only 1 Cycle Lumenator... a 2nd one is being installed.
On a bicycle at 30mph or less, this much light is pure awsome, but at the speeds these guys go it might not do it, still interesting test, trappermike mentioned 100w bulbs to replace the stock 50's... gotta look into that.
The Cycle Lumenator was also bolted on,
Pictures were taken with a blackberry, and with freezing hands so image quality is not ideal, still shows the difference, this is with only 1 Cycle Lumenator... a 2nd one is being installed.
On a bicycle at 30mph or less, this much light is pure awsome, but at the speeds these guys go it might not do it, still interesting test, trappermike mentioned 100w bulbs to replace the stock 50's... gotta look into that.
oh, also, got my hands on the pack last night to check it, and found all 4 pairs of cells at 3.6xx volts, so the pack is running at full voltage and likely slightly beyond at times, with the lights pulling power from the pack i'm hoping it prevents overcharge but i need ride data for that, with all the snow we have now i'm sure to get the chance to do it.
trappermike
100 W
The light looks great Gary! 
Please tell me about the "Cycle Lumenator"(Volts,watts,mounting ease,price,a photo!) and where I can get one,I want a really good light for my e-bike.
Also I think a "Battery Blanket" is what your friend with the Skidoo needs,they are cheap at any auto supply store,plug it into the house overnight or for a few hours before running the sled.
The 100/80 bulbs are also available at an auto parts store,also available in 130/100 too I think. Best bring the original bulb to the store so they know what type it is,it's the same used in aftermarket Bosch headlights too.
Good project you did.
Please tell me about the "Cycle Lumenator"(Volts,watts,mounting ease,price,a photo!) and where I can get one,I want a really good light for my e-bike.Also I think a "Battery Blanket" is what your friend with the Skidoo needs,they are cheap at any auto supply store,plug it into the house overnight or for a few hours before running the sled.
The 100/80 bulbs are also available at an auto parts store,also available in 130/100 too I think. Best bring the original bulb to the store so they know what type it is,it's the same used in aftermarket Bosch headlights too.
Good project you did.
trappermike
100 W
Sorry,I meant Ypedal... 
Made this video a while back of the Lumenator :
[youtube]nD32uT5HpdI[/youtube]
[youtube]nD32uT5HpdI[/youtube]
trappermike
100 W
Ok,thanks,I found them.
Wasn't Gary working on a black box LiFePO replacement for lead-acid batteries? ... a mini-bms that does all the charging/protecting of the cells that can be sealed up in the pack.
Has anyone made one of these BLACK BOX lifepo4 replacments batteries or more importantly BM's that does all the charging/protecting/balancing of the cells that can be sealed up in the pack as if it was an SLA or 12v lead acid battery with no other modfications to the charging circuit ?
Has anyone made one of these BLACK BOX lifepo4 replacments batteries or more importantly BM's that does all the charging/protecting/balancing of the cells that can be sealed up in the pack as if it was an SLA or 12v lead acid battery with no other modfications to the charging circuit ?
The pack worked perfectly fine and no problems yet, i plan to get it back for a bench test soon.
One thing however, is that this high-compression engine combined with sub freezing temps ( below -20 celcius ) is too much for a 2P pack, would need to double it up to a 4P for real cold starting but the 2P worked fine along with the DC/DC converter for the LED's..
No protection, on this specific sled it worked out well, the cells were kept right up at 3.6v and i suspect lightly over-charged while high reving the motor.. but so far so good.
One thing however, is that this high-compression engine combined with sub freezing temps ( below -20 celcius ) is too much for a 2P pack, would need to double it up to a 4P for real cold starting but the 2P worked fine along with the DC/DC converter for the LED's..
No protection, on this specific sled it worked out well, the cells were kept right up at 3.6v and i suspect lightly over-charged while high reving the motor.. but so far so good.
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