LiIon batteries for our ATC's

[Gabriel]

So me and Fixer have talked about this briefly. There are some serious pitfalls to it but if problems could be solved what a great upgrade to our older machines.

Imagine, a plug and play kit made to replace the battery that would let you simply shove a 12 or 13 volt cordless drill battery into a socket, hit the starter and go. When the machine is not going to be used the battery could be pulled in seconds and placed on the docking station that will keep it charged.

To me that would be awesome.

There are dangers to LiIon batteries. Explosion being one of them. Yikes! The whole notion may not be (affordably) possible yet but soon it will have to be as tech improves. If money is not an option $500+ will get you a LiIon race car battery. Smaller, lighter, more powerful. Can be mounted in any position.
Lots of positives here.


Anyone care to discuss?

[ps2fixer]

Just to clear up the marketing jazz from the drill companies. Some use the max voltage of the cells in the batteries, while others use the normal/neutral voltage. Generally Max voltage for a LI-Ion is 4-4.2v, normal voltage is 3.6-3.7v. So a 3 series battery would be 3x4.2v= 12.6v which is the normal/neutral voltage of the Lead Acid style battery these atv's were designed for (max is somewhere around 13.5-14.5v). A prime example of the marketing talk is a 5 series battery, 5* 3.6v = 18v, just like a Milwalkie 18v drill battery. 4.1v * 5 = 20.5v, aka Dewalt 20v batteries. There's no difference, but the Dewalt appears to be higher voltage.

That's kind of the same logic with car amps today vs long ago. When I was a kid a 400w amp was pretty huge. now there's 1600w amps, but that's the peak output. The old ones were rated in RMS, basically continuous output. The 1600w one I'm using for an example is 400W RMS.

Anyway, liability is the #1 issue for a manufacture to make these batteries. I wouldn't touch them for my business because of that fact. For DIY, drill batteries would probably be the best source since they have a solid case and atleast a discharge protection circuit and under voltage protection circuit inside of them. I'm not sure if the charge controller is in the batteries or part of the charger. If it's in the batteries, then they should charge while riding, if not, you'd have to start the machine and disconnect it so it doesn't over charge (fire hazard). A large 18v drill battery like 5ah should have enough of a discharge spec to start a 3 wheeler I'd think, but the problem is, 18v Is a bit more than what the starter would be expecting. Probably wouldn't hurt anything as long as excessive cranking is never needed (heat kills the motor in the case of over voltage, so short bursts are fine, long hard cranking is bad). Ideally you'd want a Li-Ion 10.8-12.6v battery, maybe two in parallel.

Also fun fact, drill batteries are special made, same with E-cig batteries. Generally their discharge rating is 20C-40C, while typical laptop batteries are 1C-2C. Been a while since I've read about the discharge ratings, but if I recall correctly, 1c = 1x capacity, so a 2500mah (2.5ah) cell can discharge at an average of around 2.5 amps. 20C would be 20x that, or 50 amps. The "C" rating system is more of a length of time for discharge, so the rating is more of an average instead of like CCA being a peak rating I think. Here's a good write up on the rating system.

mit.edu/evt/summary_battery_specifications.pdf

Down side to the drill batteries is getting the connector to hook up to the battery and having a large enough wire to handle the current for the starter load.

[ps2fixer]

Well, after talking to a guy doing a baja race, Lithium Ion batteries do exist for the ATV market already. Here's a link for one. It kept getting called a dry cell and I was like wtf is the metal it's made from, he looked up the specs and yep, Li-Ion. Looks like it's the pouch style normal voltage of 3.2v instead of the typical 3.6-3.7v. I don't see any mention of an internal charge controller. There must be something, but who knows if it actually balances out the cells and such like a proper charge controller would do. More tech specs would be interesting to see. For the price, and the reliability of the Li-Ion style batteries, really it isn't a bad price point, should last a good 10 years, maybe more as long as it doesn't get drained dead and the charge controller balances the cells out.

https://www.amazon.com/Antigravity-L.../dp/B008LXULV6

[M.Pargiello]

I run a lithium ion in my klr, great battery! They do have downsides but the trade off is worth it for the weight savings. You need different chargers, different ways to charge, possible fire �� etc. It’s all part of the game.

[ps2fixer]

If the battery requires a different way to charge, then how does the machine charge the battery while in use? I'd assume those pre-made batteries like that would have a charge controller built into them, so they should accept normal charging voltage like a lead acid.

[M.Pargiello]

It’s possible some do have a system like that, and I’m not smart enough to know the specifics. I was told there’s a big risk for fire if charged with a standard charger. So I don’t mess with it because it just works *knock on wood ��

[sledcrazyinCT]

Good to see this thread revived. Ironically yesterday I was speaking with a person I recently met that has a 360 scrambler he bought with Lithium Ion battery installed by the previous owner. I asked him why an old bike would need one and all he could offer as an advantage was the weight savings.

Bike currently doesn't run because he doesn't have $200 to buy the correct charger. Unfortunately I doubt he could shed much light on how the Scrambler charging system works since he hasn't run the bike at all yet. When he gets back from Florida next week I will see if he would show me the Honda to notice if anything has been modified to original harness

[El Camexican]

I just happen to be on the Ricky Stator website the other day and saw that both of my street bikes are listed as having an option for a lithium ion regulator. Apparently the factory regulators overcharge the lithium ion batteries. So far I haven’t had a problem, but I’m always concerned about fire. I run Antigravity batteries in both, incredibly powerful.

[ps2fixer]

Max charge for a Lead acid is around 14.5-15v, Li-Ion is about 3.6v per cell "normal voltage, but max charged voltage is 4-4.2v, so 3 cells would be 12-12.6v. Most lead acid systems put out 13.5-15v to charge the battery. If you over charge a Li-Ion, there's not much risk of fire unless you go like way over, however, it will shorten the life a lot. Like charging it to 4.3v per cell won't catch it on fire, but trying to push it 5v per cell isn't going to be good. Li-Ion basically will keep taking a charge beyond what it should as long as it's high enough voltage, lead acids get harder and harder to charge the higher voltage you go, which is why when you "balance charge" or active charge them, the charge voltage goes over 15v , it's not good for the battery to do that all the time (it boils the acid), but once in a while to balance the low cells out is good. Li-Ion is the same way, like laptop batteries have a charge controller built into them, sadly it's designed to be throw away, so it doesn't balance charge even though it would be easy for them to add that, but it does have over voltage and under voltage protection per cell. When they get wildly unbalanced, you have a laptop battery that works fine, but the life is like 10 minutes, if you balanced all the cells again, it would last over an hour easily. I use reclaimed laptop 18650's in my LED head lamps all the time, their life is just fine as long as they were not under 2v when I got them. I also have a capacity tester that fully discharges the Li-Ion cells and reads how much power it draws till it's to the min voltage (2.5v if I remember correctly, and most are 80%+ of rated capacity.


For these batteries that are made for ATVs, there must be a charge controller in them, if not, then they'd have a lot of liability on their hands. Most charge controllers I believe also has over amperage protection, since these cells really pack a heck of a punch. A single cell can be rated at 20-30amp for a high amp draw cell (drill etc), typical is about 5 amp if I recall correctly for like a laptop battery. Generally lower amp draw rating has higher capacity.

If the battery doesn't have a built in charge controller, then it should have a wire lead like this battery has. The two big wires are to draw power directly from the battery (no over draw protection or under voltage protection), and you charge the battery after use via the two smaller plugs with a balance charger designed for Li-Ion. There's also different breeds of Li-Ion but trying to keep this simple and to the point. Also the charger controller I mention is also often called a BMS or battery management system.



Anyway, if you want to test of the battery has a BMS, charge it up and check the voltage once in a while. Some Li-Ion types have a higher max charge voltage so I can't really say for sure what the peak voltage it should get to would be, but it should stop taking a charge on it's own regardless of what the normal battery charger is doing.


Talking about chargers, more or less there's two types of power the battery will see, half wave rectified DC (AC though a single diode), or a full wave rectified DC (AC though 4 diodes to extract power out of both sides of the AC wave). Machines designed for a battery should also have a built in voltage regulator which normally caps the voltage around 14-15v.

Anyway, for that battery photoed before my post, I'd pretty much bet the BMS is between the battery posts in that raised up area and inside the battery is either the pouch style cells (higher power density and different voltages), or the very common 18650 cells like a drill battery uses (high current output, lower capacity).

I've worked around the raw cells a fair bit. Here's an example of some specs and what they mean.

https://www.18650batterystore.com/Sa...amsung-30q.htm

Datasheet: https://www.18650batterystore.com/v/...data_sheet.pdf

Capacity, 3ah, so if you want 9ah battery, you run 3 in parallel.
Max charge current is 1.5amp, max charge voltage is 4.2v, the 4.2v spec is while finishing up the charge at 150ma (0.15a). A lot of people stop the charge 4-4.1v to increase battery life slightly by giving up a little capacity.
Discharge speed is rated at 0.2c which means 20% of capacity, or 3000ma*20% = 600ma, this is their discharge test to determine the battery capacity (600ma draw for 5 hours = 3000mah capacity)
Min voltage to be counted fully dead charge is 2.5v, below this value an Samsung is saying you're damaging the battery (longevity/life of it).
Max continuous discharge is rated at 15amp, if you need more, again parallel the cells, so 3 would be 45amp. Different models of cells have different ratings.
I don't see the spec, but normally there's like a max 30 sec discharge burst, a cell like this one normally rates like 20-30a, this rating is likely a big part of the atv li-ion batteries.
The battery is rated for 250 charge cycles, this can get a bit complex, but simply put, if you discharge the battery to 50%, then charge to 100%, you can do that 500 times, same works with 5% discharge, or 100% discharge.

Here's a little video to demonstrate overcharging/voltage. It's a bit less flames and such than the people really trying to make them catch on fire. Last one you can see they are charging it with 5.5v at 5 amps. I also didn't mention that the batterys normally have max temp specs, and the BMS has at least one temp probe to monitor the temps.

https://www.youtube.com/watch?v=YuKF8XfCVKQ

Hopefully this kind of clears some stuff up, I got a bit technical, on the cells, but sometimes details are nice to know. To catch one of these 18650's on fire is kind of a challenge, there's people that shoot them, and drill screws into them, those are the ones that really go up in flames... like this video

https://www.youtube.com/watch?v=WnZuMfq6kec

Anyway, those videos are worst case, really rare for that kind of thing to happen naturally, like getting something to probe the battery and poke a cell would be near impossible I'd think with normal riding. Even in a wreck you'd have to bend the frame in the area a lot to get something to puncher it. I'd assume the BMS is designed in a way where it's most likely fail mode is to disconnect the cells from the charge current.

[M.Pargiello]

You’re always a plethora of knowledge! Love it

[ps2fixer]

I'm nothing special, just side projects of mine that lines up to stuff on here xD. I wanted to use "junk" 18650 cells to build a house battery and figure out a system to generate power like wind to at least be slightly independent from the power company, too many power outages, and gas is expensive. Right now the project is to expand a WISP to my area so I can get at least reliable internet at a "usable" speed, like ..... 7.5/1.5mb, I'm on 1.7/0.25 but it runs like 60% of that and have issues with dropped packets and at times dialup speed bandwidth (downloads at 6-7KB/s). I can't wait to cut the CenturyLink DSL wire and never look back.

[leevarnado]

Found this on ebay

[ps2fixer]

What a crappy title, is it 12v or 10.8v lol. Remember, the engine/regulator is going to be pushing about 14.5v, sounds like too few cells to me.

[leevarnado]

He also has a 20v

[ps2fixer]

Yea, 20v would be too high of voltage, that's almost as much as two lead acids in series (24v) like a diesel pickup truck tends to use for the starter.

If you can find one of the 14.x Li-Ion drill batteries/adapters, that *should* work. The battery has a built in BMS and the chargers generally are just a power supply. For the price of the drill batteries, unless you already had them, it seems like buying an actual battery designed for an atv would be better, even if just for the sake of easier mounting. Doesn't hurt to think outside the box though =).