Round nd round... Could someone just post me a link!!

[Low]

Hiya, im reading and reading and just want s9meome cleverer than me to confirm.

1000watt rear hub
48volt
91 25r cells 7p 13s

Really want to seal the battery and controller away in my frame build and not worry about it from month to month, hense the 25rs over the 30qs figure they just wont heat up at all? would anyone be able to post a link to a buyitnow BMS, happy to spend proper money on it as dont want to be doubting it every ride.

Not sure on the specs of the controller either can you tell so as to recomend a BMS just from its casing? does the controller specs matter when choising a BMS?

Massive appreciation to everyone

Ps if anyone wants my pedal assist and brake cut offs.. PM, send me a stamped addressed and il post them to you. (Im not using them in this build)

Low

 

[D8ve]

Fit one set of brake cut outs at least. Sometimes throttles fail wide open.
Sitting on a bike that's running away in traffic could be very bad for your health.

 

[Low]

You are, of course, right Dave, but im set on going without.

Got a lovely set of Sram hydraulics no way is that motor pushing past those disks at full grab also got a little on/off click button on the throttle prob not to be trusted but then, what is!.. I just like the rawness of it, decent bike, tough battery, motor and throttle..Simple is best.

"Theres nothing worth riding that can't hurt you" (Peter Stringfellow)

Really after BMS advice only in this one

No more health nd safety please guys.

 

[Low]

Also Dave... I live in Norfolk, when you say "traffic" do you mean that annoying tractor that goes by every other Wednesday morning?

 

[Fordulike]

Samsung 30Q's will not heat up believe me. I'm running a 13s4p 12Ah 30Q pack with a 25A controller, and it performs very well indeed. It is capable of providing a continuous 60 amps, so is operating well within limits.

91 25r cells 7p 13s??? That pack will be massive and heavy. Not something I would be comfortable with fitting in a bike frame.

Not my call, but I think you will be disappointed with that kit.

Don't say I didn't warn you

 

[Low]

Mmm do you think, i did debate for ages on the battery... To be more honest the 30qs were just that bit more expesive, that was a factor.

My last build was 143cells rear and 65 frame over 200 total... Fairly happy thus will be fine frame mounted, got a strong bracket and the weight will be as low as pos.

17mAh from this build.. Would have got 21 from using.... For my needs tho this will be spot on.. On a tanget, dont you get much voltage lag with your Qs?


After a BMS suitable for my build.. Can anyone set me up with a link?

 

[Low]

Also Ford, just for comedy value... Your battery is 12Ah... My grandma says you need to man up and range up..
Dont blame me, shes a feisty one!

So, health and safety and build critiques aside.... Anyone recomend a decent BMS?

 

[Fordulike]

Mmm do you think, i did debate for ages on the battery... To be more honest the 30qs were just that bit more expesive, that was a factor.

My last build was 143cells rear and 65 frame over 200 total... Fairly happy thus will be fine frame mounted, got a strong bracket and the weight will be as low as pos.

17mAh from this build.. Would have got 21 from using.... For my needs tho this will be spot on.. On a tanget, dont you get much voltage lag with your Qs?


After a BMS suitable for my build.. Can anyone set me up with a link?

Ok, seems like you're happy with battery positioning and weight.

The 30Q's are simply amazing for performance. I don't have any raw figures for the voltage sag, but the battery meter on the display doesn't drop any bars until the pack is at least 3 quarters empty. I can judge, just by the way the bikes rides, that the 3OQ's far outperform my previous 29E pack.

Dunno if this link is any help:

Battery Protection BMS PCB Board W/ Balance for 13 Packs 48V Li-ion Cell 48x65mm

As for my pack only being 12Ah, it fits my needs. My ventures are all manly forest rides, nothing like your picnic excursions... Ahem

 

[Low]

Thanks mate, thats a nice price too, i wasnt sure that 25amp would be enough or if it would be restrictive in any way but if you are happy with that one then i am.

My grandma says that you shouod enyoy your forest rides, but she wouldnt of sold her Honda Goldwing for anything less than 15ah.

 

[Fordulike]

Thanks mate, thats a nice price too, i wasnt sure that 25amp would be enough or if it would be restrictive in any way but if you are happy with that one then i am.

My grandma says that you shouod enyoy your forest rides, but she wouldnt of sold her Honda Goldwing for anything less than 15ah.

Just to confirm, I haven't personally used that particular BMS!

If the controller shown in your listing is rated at 30 amps or less, then I see no reason why it shouldn't be ok. Controllers do overshoot their rated current, which is why I suggest 30 amps.

The BMS in the link has a short circuit protection of 40 amps, so I'm guessing it can handle peaks of up to around the 35 amp mark. Wouldn't want to push it to peak currents of 40 amps, as it may keep tripping.

Your kit listing specs are a bit vague, so not really sure what you'll end up with

 

[Deleted member 4366]

I'm not too sure what the question is, but if you already have the kit, the first thing is to look at the controller to see what the maximum current is. Divide that by 7 for a 7P cell configuration to get how much current each cell has to provide. Look at the spec for the cells for the maximum continuous current. If you're below that, you shouldn't have a problem with heat.

For the BMS, you need a safety margin of at least 30% above the maximum controller current, so up to a 22 amp controller use a 30 amp BMS. For a controller between 22A and 30A, use a 40A BMS, etc. You also need to think about the future - whether you'll use the battery for something else that takes more current.

That BMS above would be good for about 15A continuous as it only has 4 mosfets. It's not enough. This one should be OK,. With 10 mosfets, it should be able to provide 2 1/2 times more power than the other one:

https://www.aliexpress.com/item/Free-Shipping-48V-40A-BMS-13S-48V-54-6V-li-ion-battery-BMS-PCM-40A-continuous/32283657890.html?spm=2114.01010208.3.1.BBBA91&ws_ab_test=searchweb0_0,searchweb201602_4_10065_10130_10068_433_10136_10137_10138_10060_10062_10056_10055_10054_302_10059_10099_10103_10102_10096_10052_10053_10050_10107_10051_10106_10084_10083_10080_10082_10081_10110_10111_10112_10113_10114_10078_10079_10073_10070_10122_10123_10126_10124,searchweb201603_9,afswitch_1,ppcSwitch_4,single_sort_0_default&btsid=9cff0e1c-65f2-4fae-99de-84863fc7e03c&algo_expid=7b80c5bd-cd0c-4b15-8fc9-da249198dbae-0&algo_pvid=7b80c5bd-cd0c-4b15-8fc9-da249198dbae