When you pull currents above what your lipos can really do, they get hot and the electrolyte in the battery starts to break down faster. This results in 2 components, lithium and oxygen, being released inside, and with heat, more oxygen is released than can be absorbed, which results in swelling.
This is why you want to go far less then the rating when it comes to charging and discharging. Just because you calculate the max amp rating to 100a lets say, doesn’t mean it can do 100a without puffing up. I would take a quarter of the rating at best, with zippys, and an eighth for multistar packs.
Over discharging and over charging also cause this reaction to occur faster.
Li-ion is safer and easier is this regard, but they also can output far less amps at any given moment for the same price and space and the voltage sags more, resulting in less power compared to a lipo.
Thanks for explaining this, I’m not too fussed about power, for the board. So a less powerful, safer battery is good in the situation I’m just looking for the best lithium Ion battery I can get for my budget and will function well with board.
You want a battery pack built with Samsung 30Q cells. These are the cells most people in the DIY scene are using, since they really are best combo of capacity (high), discharge rate (high), and sag (lowest of li-ion).
But li-ion is 3-4 times as expensive as lipo. Most of these packs are in the $200 - $300 assembled for a smaller pack, larger ones can run $600+.
Best case, you need at least a 6s4p of 30Q cells. That’s 24 cells at ~$5 a piece. So about $100 there. And then a bms, around another $40 - $60. Charger is another $20 -$30. Then plugs and assembly, will probably run you another $40 (very lucky) - $80. All in all, at least $200 for the whole thing. And that’s a pretty small battery.
I use zippy lipos myself, and this guy can pack a decent punch.
But the real issue is you need a VESC instead of that controller your using. You can’t adjust settings to limit current for example or prevent over discharging. So li-ion or lipo, your going to burn though more batteries.
That esc can only do 6s. I would recomend the OP jump on the focbox deal that’s going on right now though so he can proper manage the battery pack while in operation. Not to mention the quality of ride difference is night and day.
Just to clarify, if you did use a battery pack with a bms inline (not bypassed for discharge), it would protect your battery from over discharge. But those are hard shutdowns that can throw your off your board (this is a mistake enertion made on the original raptor 1). A VESC based esc will gradually throttle back the power and allow you to get all of the power from your battery, instead of, oh you hit this voltage, no more power all of a sudden.
My recommendation for lipos is stick with zippy. They have a good reputation. You can just search for 6s zippys that are over 5000 mah.
You want at a min 100 wh to be safe. wh = ah * nominal voltage. With 6s, that’s 22.2 volts. So anything less than 5ah at 6s will run you risky of not getting the range you need.
Also, weight and especially hills play a big roll. Efficient drive trains get around 10 wh per mile with light riders and on flats at 15 mph top speed and 5 mph min speed. Even a minor hill will eat 4 times as much energy as on flat. So now if your whole trip is on a minor hill, with 100 wh, you’d maybe get 3 miles at best. Now steeper hills, can be as much as 16 times as much. So you have to look at your route, and take a guess as to how much is up hill vs flat.
The one I listed you is my best recommendation that I believe would get you the range you need, assuming your a lighter guy with mostly flats and not steep hills.
Just be careful, the false economy is real. It’s easy to buy cheap, break it, and have to replace it. We’ve all done this. If this is a serious transportation use as it seems to be for you, reliability, as well as durability, should be high factors on your list (late to work cause your board broke down? Easy to get in trouble here). A proper investment of ~$400 for a good li-ion pack and good vesc (do not buy the sub $100 vesc’s if you want durability), will go a long way.
I use a DIY electric bike for work, and I burnt through 3 $100 vesc’s in under a month. Then, spent the $300 for an official vesc 6 and now 4 months later and no problems. I should of just bought the official one from the beginning, would be $300 richer. I also push it hard, which is probably why they kept breaking. But not all are created equal. Even the same looking one, could have 2 different qualities of assembly, and fake components are a serious problem in escs.
Why do you want a hardcase lipo? They are just as likely to puff and are usually more expensive also.
God dam, I would love to meet you in person. You know so much. I think I will but go for a basic battery this time, if everything goes well I will look at a fill rebuild with a new vesc, li-Ions and dual motors.
Experience and passion my friend. I learned a lot through trail and error. Back when I started 4 years ago, there were no experts to turn to for advice. So idk how many thousands of dollars later, I learned a lot.
I myself use the standard (I cant find it on hk anymore tho) 2x zippy 3s 5000mAh 20c lipos in series and they serve me well. You even have higher C-rating so thats a bit better. I’ve never done a range test but I can go (with the 5000mAh) around 8km which is enough for only in the city but after some riding I personaly would have liked some more range. You have a slightly lower range (because of the 4500mAh) so you can try it but maybe you want some extra range