thinking about going lipo

[Mikeyrides]

Right now I am using a balance charger. I have a BMS that I’ll get around to wiring up eventually.

[mutantbass]

Ok. If you get stuck with wiring, ask in here. I will help you out.

Is the lack of voltage sag noticeable?

[Mikeyrides]

Thanks man. Yes! I haven’t noticed any yet and I’ve got everything setup for torque not speed. I’d rather have that launch and I definitely take advantage of the full torque a lot.

[Mikeyrides]

So to breath life back into this thread, a question I forgot to ask before I bought my last packs, is it better to have a higher C rating and low Ah or lower C rating and higher Ah? What I have now is 2* 13Ah 25c but I’m thinking about getting a couple more.

[Blise518B]

That depends on your needs. Do you want more range or more power?
In my experience C ratings often vary a lot between different manufacturers but the actual performance is somewhat similar. Some ratings are continuous some are burst and its often not very transparent. If you are happy with your current ones get more of the same so its easier to use them together.

[b264]

Your C rating times your Ah is what matters, so the less capacity you have, the higher C ratings you need. If you have 20Ah lipos then the C ratings can be a lot lower than 2500mAh lipos which need a super high C rating. Assuming everything else is normal.

[Mikeyrides]

Perfect👍 that just brought everything into perspective.

[Geo_Engineering_FTW]

thinking of trying Lipo as just seen @mutantbass post this on good deals. Ngl, ive never made a battery and have never understood the Wh metric, have only ever understood the configuration metric (i.e. 12s4p).

A few of questions:

1. For about £100 I get 4 of these
   
   
   
   What is this equivalent to in config terms (i.e. is it close to 12s1p)?
2. I can fit 4 of these in an enclosure, is this easy to connect them? - what tools do i need?
3. Is adding this smart BMS to them going to be difficult? (looks like a nighmare)

cheers

[Evwan]

Adding a BMS will be a bit of a nightmare, but of you have 4 of these it’s hard to call it a 12s1p. Easiest thing to “compare” it to is a 12s2p 40T pack, but they’re two very different things. Besides the BMS you just need to put them all in series.

[Geo_Engineering_FTW]

I can look on youtube for lipo guides I think, maybe even the old forum might have guide. 12s2p 40t pack is pretty solid for 100 quid.

@Evwan

but they’re two very different things

I have got this impression. Many jumpers use them, as I guess it can deliver more amps in bursts, or something. Anyway migh be a fun option to try for a small street build

[mutantbass]

Well, aren’t you fucking lucky

LIPO Charge only Smart BMS wiring Guide

Alright folks, have some time on my hands so decided to make this guide. We are going to be wiring 4x 3s lipo batteries to a smart Bluetooth LTT bms (available on https://www.lithiumbatterypcb.com/ ) in charge only to make a 12s lipo. The goal here is to be able to monitor individual cell voltages from a smartphone and charge the batteries from a charge port on the enclosure and not have to take them out every time. This is the best solution I have come up with for flying with my board and tak…

Those are equilavent to a 12s2p of Samsung 40T or molicel 42a cells. You are getting a total of 355 watt hours.

3.7v nominal x 3s x 8ah = 88.8wh per battery x 4 batteries = 355.2 watt hours.

[Geo_Engineering_FTW]

haha, fuck me. nice one

might even try a massive one for a pelicase emtb at that price.

cheers

[Geo_Engineering_FTW]

@mutantbass , just wondering, i’ve heard that Lipos get easily wrecked, because of general user negligence (like not dissipating the battery enough/too much). Does adding the BMS somehow make them more long lasting/help avoid these things, or will these issue’s with them (compared to Lithium Ion) still stand regardless of whether you use a BMS? (I know BMS just regulate/balance cells, but maybe this has a positive effect on them too?)

[mutantbass]

Keep them between 3.55v/3.6v and 4.15v per cell. They will last hundreds of cycles. People discharging their lipos down to 3v and then come complain about lifespan. Take your lithium ions to 2v per cell and see what happens.

The BMS is there so you don’t have to take them out every time to charge on a Lipo charger.

LiPos on a street board: The no-enclosure enclosure

Yeah. RC LVC doesn’t really translate to esk8. The equivalent esk8 usage would be going uphill 30 degrees full blast and emptying the battery in 20 minutes. In those circumstances, 3.5v might well mean you still have 50% battery left due to voltage sag. But for the most common esk8 usage which is very start/stop in terms of amp usage, 3.5v most likely means that you have used all your capacity and are damaging your cells.

thinking about going lipo

I exclusively use LIPOs. This is my current setup on a trampa/kaly hybrid with a bms. I also used them before on a split enclosure flexy deck. This current setup is 3s x 4 8ah each and I can take them on a plane (88wh each battery). I know it looks complicated but trust me, it is 1/10th the work of building a li-ion pack. the whole thing took me an hour while I was watching tennis at the same time. lol Here is what I have learned. Keep the battery between 3.6v and 4.15v per cell and you won’t…

[Geo_Engineering_FTW]

Excellent work here man. Will have a read and join the Lipogang

[Mikeyrides]

Watching your discharge is really important, one for lifespan and two for charging. I accidentally discharged mine to about 3.1 volts and the charger wouldn’t read it. It kept saying, “incorrect cell count”. I had to bring up the voltage to about 3.5, through a different charging mode, for the charger to recognize the battery. I only charge to 4.15v as well and get around 20-25 miles on a emtb depending my riding style. And they have massive punch​:ok_hand: the first day after getting them my board shot out from under me

Edit: I have two 13ah 6s in series.

[mutantbass]

@Mikeyrides

I accidentally discharged mine to about 3.1 volts

Do you have a lipo charger that can measure internal resistance?

[Mikeyrides]

Yeah, everything is reading normal still, internal resistance is good, cells are perfectly balancing before and after a ride and capacity is good.

[Red_souls]

Any of you guys run fuses between your lipos and VESC? Just wondering because I’m making my first board right now and confused on if I need a fuse between those, I know for sure I need one for the BMS and charge port, other then that. Got no idea where else

[poastoast]

i ran no fuse