Getting datasheets for batteries

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Gonery

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Hi everyone,
I'm part of a Formula Student team and we're building a hybrid formula car. For the battery pack, I wanted to investigate using RC batteries, since they get much better power density both charging and discharging than anything else commercially. I was absolutely amazed when I found the Turnigy Nano-Tech Plus batteries with 70C discharge and 30C! charge. For a race car with regenerative breaking, that would be great. However, here's the problem:

The competition requires a datasheet with at least the min and max battery voltage, max discharge and charge current, and the allowable temperature range for charging and discharging.

I tried contacting pretty much every Li-Po manufacturer I found (including literally every Li-Po distributor in my country, the Czech Republic), including: Amewi, df models, E-flite, gensacearespammers/tattu, Himoto, HPI Racing, Kavan, KOnect, LRP/Nosram, Onyx, Ruddog, Spektrum (same contact as ruddog), Spektrum, Team Corally, Team Orion, Traxxas and of course, Turnigy (they don't list a contact on their website, tried HobbyKing). However, the only one that has been able to actually provide a datasheet so far is HPI Racing, hats off to them.

So that's where I'm at and why I'm turning to you. Please, if you have any information about how to contact any company that makes good Li-Pos, especially Turnigy, have any experience how to get datasheets for Li-Pos or even have the actual datasheets, I'd be extremely grateful for the help.
 
Depending on which manufacturer you use, you can probably get a MSDS sent to you if you contact them.
 
Depending on which manufacturer you use, you can probably get a MSDS sent to you if you contact them.

MSDS is usually just going to be chemical composition and hazard stuff based on what we get with the LiFePo and Lion batteries we sell.

Here is an MSDS from a battery we sell. https://s1.solacity.com/docs/BattleBorn/MATERIAL_SAFETY_DATA_SHEET.pdf

Charge, discharge, and storage numbers are spotty like rc batteries. https://battlebornbatteries.com/product/12v-lifepo4-deep-cycle-battery/

I would guess that most of these companies wouldn't have anything concrete on that because they would have to admit that most of the numbers they use are not based on a truly standardized testing, like C rating being all over the place.
 
I was absolutely amazed when I found the Turnigy Nano-Tech Plus batteries with 70C discharge and 30C! charge.
The advertised C ratings are complete lies. About the highest TRUE C rating you can find on a Lipo is about 40C discharge or so on the best of LiPos. If you want your batteries to last I wouldnt charge them over 2 or 3 C and most manufacturers advertise a limit of about 5C charge rate.

So that's where I'm at and why I'm turning to you. Please, if you have any information about how to contact any company that makes good Li-Pos, especially Turnigy, have any experience how to get datasheets for Li-Pos or even have the actual datasheets, I'd be extremely grateful for the help.
Try RCBattery.com. Thats a US based company and they make some of the better lipos I've ever tested.
 
Try RCBattery.com. Thats a US based company and they make some of the better lipos I've ever tested.
Thanks for the tip, those Liperions look really good, hopefully they'll respond :D If it goes well, I wonder how shipping the batteries over to the Czech Republic will go though
The advertised C ratings are complete lies. About the highest TRUE C rating you can find on a Lipo is about 40C discharge or so on the best of LiPos. If you want your batteries to last I wouldnt charge them over 2 or 3 C and most manufacturers advertise a limit of about 5C charge rate.
The funniest part for me is that they aren't even believable lies. Take the "gensacearespammers bashing 8000 mAh", which claims 100C (800A) continuous through an EC5 plug... which is rated for 40A :oops: That's on the line even with the 5C maximum charging current they claim...
As for my application, we're building the car for peak performance, even at the cost of its lifetime. For example, the planetary gearboxes for our hybrid powertrain motors are designed for a lifetime of 50 hours. So I don't mind torturing the cells even at the cost of reduced cycle life if it means increased performance. Realistically, the maximum current drawn from the hybrid pack is going to be 15-20C, with maybe a peak power mode for the sprint event. The load is also not going to be anywhere constant, mostly just for helping with acceleration from low speeds, but for the car to be able to keep this up with a total cell weight limited to 3kg, the only option other than dropping the power to levels where the hybrid powertrain can barely offset its own weight is to do heavy energy recuperation when braking.
That is the whole reason why I'm turning to Li-Po RC batteries, pretty much the only other available option is using Li-Ion cells, but their chemistries aren't really meant for these insane currents. Probably the highest charging current available is 3C specified by Molicel on some of their batteries, with charge rates somewhere at or below 15C, which they realistically can't even reach without overheating due to their comparatively higher internal resistance.
 
Thanks for the tip, those Liperions look really good, hopefully they'll respond :D If it goes well, I wonder how shipping the batteries over to the Czech Republic will go though

The funniest part for me is that they aren't even believable lies. Take the "gensacearespammers bashing 8000 mAh", which claims 100C (800A) continuous through an EC5 plug... which is rated for 40A :oops: That's on the line even with the 5C maximum charging current they claim...
As for my application, we're building the car for peak performance, even at the cost of its lifetime. For example, the planetary gearboxes for our hybrid powertrain motors are designed for a lifetime of 50 hours. So I don't mind torturing the cells even at the cost of reduced cycle life if it means increased performance. Realistically, the maximum current drawn from the hybrid pack is going to be 15-20C, with maybe a peak power mode for the sprint event. The load is also not going to be anywhere constant, mostly just for helping with acceleration from low speeds, but for the car to be able to keep this up with a total cell weight limited to 3kg, the only option other than dropping the power to levels where the hybrid powertrain can barely offset its own weight is to do heavy energy recuperation when braking.
That is the whole reason why I'm turning to Li-Po RC batteries, pretty much the only other available option is using Li-Ion cells, but their chemistries aren't really meant for these insane currents. Probably the highest charging current available is 3C specified by Molicel on some of their batteries, with charge rates somewhere at or below 15C, which they realistically can't even reach without overheating due to their comparatively higher internal resistance.
Sounds like a cool project. Update us from time to time with some pics or progress reports :)
 
Thanks for the tip, those Liperions look really good, hopefully they'll respond :D If it goes well, I wonder how shipping the batteries over to the Czech Republic will go though

The funniest part for me is that they aren't even believable lies. Take the "gensacearespammers bashing 8000 mAh", which claims 100C (800A) continuous through an EC5 plug... which is rated for 40A :oops: That's on the line even with the 5C maximum charging current they claim...
As for my application, we're building the car for peak performance, even at the cost of its lifetime. For example, the planetary gearboxes for our hybrid powertrain motors are designed for a lifetime of 50 hours. So I don't mind torturing the cells even at the cost of reduced cycle life if it means increased performance. Realistically, the maximum current drawn from the hybrid pack is going to be 15-20C, with maybe a peak power mode for the sprint event. The load is also not going to be anywhere constant, mostly just for helping with acceleration from low speeds, but for the car to be able to keep this up with a total cell weight limited to 3kg, the only option other than dropping the power to levels where the hybrid powertrain can barely offset its own weight is to do heavy energy recuperation when braking.
That is the whole reason why I'm turning to Li-Po RC batteries, pretty much the only other available option is using Li-Ion cells, but their chemistries aren't really meant for these insane currents. Probably the highest charging current available is 3C specified by Molicel on some of their batteries, with charge rates somewhere at or below 15C, which they realistically can't even reach without overheating due to their comparatively higher internal resistance.

EC5 is rated for 120 amps but you are correct about the numbers being BS. If they were legit numbers a lot more people running Deans connectors on their 3s+ setups would be melting them down.

Could you run a capacitor system with Lion batts for bursts?

I know that Ford has the Mach E setup so that it can only do max current for a couple of seconds to avoid overheating things. Heat dissipation is an issue. Check out the cooling system for the hybrid side of the Chevy Volt. It was a pain to work on.
 
Could you run a capacitor system with Lion batts for bursts?
That wouldnt help with the regenerative breaking aspect though.

Thanks for the tip, those Liperions look really good, hopefully they'll respond :D If it goes well, I wonder how shipping the batteries over to the Czech Republic will go though

The funniest part for me is that they aren't even believable lies. Take the "gensacearespammers bashing 8000 mAh", which claims 100C (800A) continuous through an EC5 plug... which is rated for 40A :oops: That's on the line even with the 5C maximum charging current they claim...
As for my application, we're building the car for peak performance, even at the cost of its lifetime. For example, the planetary gearboxes for our hybrid powertrain motors are designed for a lifetime of 50 hours. So I don't mind torturing the cells even at the cost of reduced cycle life if it means increased performance. Realistically, the maximum current drawn from the hybrid pack is going to be 15-20C, with maybe a peak power mode for the sprint event. The load is also not going to be anywhere constant, mostly just for helping with acceleration from low speeds, but for the car to be able to keep this up with a total cell weight limited to 3kg, the only option other than dropping the power to levels where the hybrid powertrain can barely offset its own weight is to do heavy energy recuperation when braking.
That is the whole reason why I'm turning to Li-Po RC batteries, pretty much the only other available option is using Li-Ion cells, but their chemistries aren't really meant for these insane currents. Probably the highest charging current available is 3C specified by Molicel on some of their batteries, with charge rates somewhere at or below 15C, which they realistically can't even reach without overheating due to their comparatively higher internal resistance.
Have you looked in to using LiFePO4 batteries? IDK how they stack up to LiPo in terms of discharge and recharge rates but I do know that this is a really common thing for the bass heads to use in their redonkulous 25000W+ car stereo systems. May be worth a look.
 
That wouldnt help with the regenerative breaking aspect though.


Have you looked in to using LiFePO4 batteries? IDK how they stack up to LiPo in terms of discharge and recharge rates but I do know that this is a really common thing for the bass heads to use in their redonkulous 25000W+ car stereo systems. May be worth a look.

Forgot about the regenerative braking aspect.

This is from the website of the manufacturer for the LiFePo4 batteries we sell.

The continuous discharge rate of our batteries is 100 amps, 200 amps for 30 seconds and higher loads for ½ second. Cold cranking applications typically exceed 200 amps which will cause our batteries to shut off.

When I built car stereos years ago we relied heavily on capacitors, AGM was the high end at that point but from some brief research it looks like they still do quite a bit for the burst power.
 
Thanks for the ideas guys, I really appreciate you trying to help me out and figure something out

The capacitor idea is interesting. We also considered it for peak loads (2-10s). I'm not sure whether I've mentioned this already, but the battery pack is limited to 3 kg of "active material", which means cells, capacitors or any other electricity storage. The main problem here is that 3 kg of cells is just way too little for how high the capacity of the pack has to be (500 Wh minimum, ideally 800 Wh or more).

The LiFePo battery idea unfortunately has the same problem. While Li-Po batteries have gravimetric densities (very roughly) of 150-220 Wh/kg and Li-Ions are anywhere from 190 - 240 Wh/kg (for comercial "high power" cells), LiFePo4 cells tend to be around 90 - 140 Wh/kg and in terms of charge/discharge performance, they are pretty similar to Li-Ion batteries or worse. I am generalising of course, a lot of exceptions exist, like shorai batteries. I have the "LFX14L2-BS12" ready for measuring at the university (although I probably won't be able to get a suitable datasheet either). Internally, it is a 4S2P pack made out of pouch cells marked "2000 mAh" (I don't think the people at Shorai know how amp-hours work 😅), they even have a cell designation, google doesn't find anything though. I don't remember the exact values, but the gravimetric density (if their specifications are true) would be around 280 Wh/kg. Interestingly enough, the pack doesn't have any internal protections or balancing circuits and you're meant to just stick it in your bike instead of a normal lead-acid battery... Explains why both batteries we had from them on our past cars puffed up.

A middle ground somewhere in there would probably be LTO (Lithium Titanate Oxide) batteries. They have low gravimetric energy density (very roughly 60-80 Wh/kg), but can generally take >10C charge and discharge reliably. Of course, their lower total capacity means that to even get the same power as a Li-Po/Li-ion pack of the same weight, they would need to handle 2-3 times as many "C"s. Unfortunately, they aren't very wide spread and the handful that are available aren't good enough.

Try RCBattery.com. Thats a US based company and they make some of the better lipos I've ever tested.
I tried asking them for a datasheet and whether they ship to the Czech Republic, which they unfortunately they don't, so they didn't react to the datasheet part, since it didn't matter. Even though it would be pointless, I'm still curious whether they would be able to provide one
 
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