Question Custom pre PTB Piranha P1 build

[Jacob BV]

I've just bought a 2nd pre PTB P1 (2015 serial 091), thats had it's battery replaced 2 years ago by a e-bike company - they didn't change anything apart from the battery. Many thanks if anyone can help with any of below

1) What were the pre PTB stats I'm struggling to find them? This new battery was made to be about 1.5 times the capacity.

2) A long term project of mine might be to pick up a 2nd hand battery section, and making my own batteries for both sections. I should be fine doing this with either a pre PTB or post right?

3) It feels like you could fit more battery in if you cut some of the battery bracket ends off, has anyone done this?

 

[sea_ledford]

I can't help with most of your question, but you might need to be careful about adding more batteries. Even if they fit, and it all works great, you might just make the whole thing negatively buoyant. Adding positive buoyancy will require adding material to the outside of the scooter to increase displacement. Depending on the amount of power gained and the amount of drag added, you might end up with a lower performing scooter than leaving it stock.

 

[Jacob BV]

I can't help with most of your question, but you might need to be careful about adding more batteries. Even if they fit, and it all works great, you might just make the whole thing negatively buoyant. Adding positive buoyancy will require adding material to the outside of the scooter to increase displacement. Depending on the amount of power gained and the amount of drag added, you might end up with a lower performing scooter than leaving it stock.

Totally agree, I'd take into account the weight wiggle room I have too - leaving some spare for trimming out.

 

[nickbutcher]

I've just bought a 2nd pre PTB P1 (2015 serial 091), thats had it's battery replaced 2 years ago by a e-bike company - they didn't change anything apart from the battery. Many thanks if anyone can help with any of below

1) What were the pre PTB stats I'm struggling to find them? This new battery was made to be about 1.5 times the capacity.

2) A long term project of mine might be to pick up a 2nd hand battery section, and making my own batteries for both sections. I should be fine doing this with either a pre PTB or post right?

3) It feels like you could fit more battery in if you cut some of the battery bracket ends off, has anyone done this?

Late to this but my P1 battery pack from 2015 stated 417Wh. I assume that this was the nominal capacity based on the pack being built from LG MG1 cells which were supposed to be 2850mAh when new.

I've seen other pre-PTB packs with a stated capacity just under 400Wh so I assume they used different cells.

I've just rebuilt the pack using LG MJ1 cells (3500mAh) and a JBD smart BMS so I can monitor the charging and battery health on my iPhone via Bluetooth. My nominal capacity is now just over 500Wh - an increase of over 20%.

The battery pack is constructed from 40 18650 cells configured as 10S4P. It only just fits inside the shell so adding an extra series wouldn't be ideal and, as others have said already it would add weight. You might get away with it in salt water with the salt water plates removed.

If you want more pack capacity, go for bigger capacity cells but 3600mAh is just about the max for 18650s.

 

[Jacob BV]

Late to this but my P1 battery pack from 2015 stated 417Wh. I assume that this was the nominal capacity based on the pack being built from LG MG1 cells which were supposed to be 2850mAh when new.

I've seen other pre-PTB packs with a stated capacity just under 400Wh so I assume they used different cells.

I've just rebuilt the pack using LG MJ1 cells (3500mAh) and a JBD smart BMS so I can monitor the charging and battery health on my iPhone via Bluetooth. My nominal capacity is now just over 500Wh - an increase of over 20%.

The battery pack is constructed from 40 18650 cells configured as 4S10P. It only just fits inside the shell so adding an extra series wouldn't be ideal and, as others have said already it would add weight. You might get away with it in salt water with the salt water plates removed.

If you want more pack capacity, go for bigger capacity cells but 3600mAh is just about the max for 18650s.

amazing thanks for this. If you have any pictures of the build that would be amazing

 

[lostsheep]

Late to this but my P1 battery pack from 2015 stated 417Wh. I assume that this was the nominal capacity based on the pack being built from LG MG1 cells which were supposed to be 2850mAh when new.

I've seen other pre-PTB packs with a stated capacity just under 400Wh so I assume they used different cells.

I've just rebuilt the pack using LG MJ1 cells (3500mAh) and a JBD smart BMS so I can monitor the charging and battery health on my iPhone via Bluetooth. My nominal capacity is now just over 500Wh - an increase of over 20%.

The battery pack is constructed from 40 18650 cells configured as 4S10P. It only just fits inside the shell so adding an extra series wouldn't be ideal and, as others have said already it would add weight. You might get away with it in salt water with the salt water plates removed.

If you want more pack capacity, go for bigger capacity cells but 3600mAh is just about the max for 18650s.

4S? Is this a typo?

 

[nickbutcher]

4S? Is this a typo?

Ha ha, yes - 10S4P

Fixed now - cheers

 

[nickbutcher]

amazing thanks for this. If you have any pictures of the build that would be amazing

I took a few...

 

[Jacob BV]

I took a few...

Did you change the power connector there, mine is different to that.

 

[nickbutcher]

Did you change the power connector there, mine is different to that.

No. That's an XT90 that will be inside the tube to connect the pack to the longer cable that then connects to the motor - still using the large Andersons to connect the battery tube to the motor.

It means that I can just disconnect the cable if I do this again in the future or I could make another pack that I could swap over quickly if necessary, without any soldering.

I'm toying with the idea of making a larger pack using 21700 cells which could give me more capacity than a standard P2 without the extra length.