Wich case/bag would you reccomend for my battery?

[Betotap93]

Hello guys, i'm new aroudn here, so nice to meet you everybody.

I got a BBS02 750w, into a Trek Marlin 5 gen 1, in my country (Chile) is very hard to find batteries, and the ones that are available are way too expensive, around $600 for a 17.5 ah. So i buy a PVC Liitokala 25 ah 48v battery, and buy a bag for it, i'm still waiting for the battery to arrive, but i want to secure it, so maybe the bag will be just for a reduced time.

The battery dimensions are: (300*115*75mm)± 2mm, and weights around 4kg. I was looking for a downtube case, like a Dolly P7 -P9 or a Hailong Max, but i don't know if this will work. Or maybe a Silverfish case and attach it to the rack. I'm still not sure, as a im really a newbie in all of this.

I share my bike, before the motor install, and with the bag that will hold the battery. Plus inside dimensions of the frame (in cm).



Thank you all!

 

[saneagle]

Hello guys, i'm new aroudn here, so nice to meet you everybody.

I got a BBS02 750w, into a Trek Marlin 5 gen 1, in my country (Chile) is very hard to find batteries, and the ones that are available are way too expensive, around $600 for a 17.5 ah. So i buy a PVC Liitokala 25 ah 48v battery, and buy a bag for it, i'm still waiting for the battery to arrive, but i want to secure it, so maybe the bag will be just for a reduced time.

The battery dimensions are: (300*115*75mm)± 2mm, and weights around 4kg. I was looking for a downtube case, like a Dolly P7 -P9 or a Hailong Max, but i don't know if this will work. Or maybe a Silverfish case and attach it to the rack. I'm still not sure, as a im really a newbie in all of this.

I share my bike, before the motor install, and with the bag that will hold the battery. Plus inside dimensions of the frame (in cm).

View attachment 62663

Thank you all!

You have to be very careful with bags. Many times, when we see a photo of an ebike fire, the battery is in a bag. I think part of the problem is that there's too much movement inside the bag, which lets the battery bounce around until a wire becomes dislodged or one of the welded cell connecting strips wears through the celll heat-shrink insulation to cause a short. If you must use a bag, put loads of extra insulation around the battery until it's absolutely tight in all directions.

 

[Nealh]

My lipo bricks used to be packed in like sardines to prevent any movement , that was when I used to carry about 12 bricks all wired in P then S.
Now adays it is so much easier with nice qulaity 18650 or 20700's spot welded as one.

 

[Betotap93]

You have to be very careful with bags. Many times, when we see a photo of an ebike fire, the battery is in a bag. I think part of the problem is that there's too much movement inside the bag, which lets the battery bounce around until a wire becomes dislodged or one of the welded cell connecting strips wears through the celll heat-shrink insulation to cause a short. If you must use a bag, put loads of extra insulation around the battery until it's absolutely tight in all directions.

This is exactly what worries me the most, i bought foam to put in place once the battery arrives, but i want to find a more permanent solution, like putting it inside of a hailong case or a similar thing.

 

[AntonyC]

If I understand correctly the battery you've bought is a welded cell pack so it probably won't fit the downtube cases you mention because they're a close fit to their chosen cell-holder layouts. Roll top panniers have the edge over frame bags for waterproofing, and to absorb local impact you can add rigid panels over the foam (like in the cell pack only more effective), then more foam to stabilise all that inside the bag. Liitokala cells aren't great quality so try to avoid taking the battery indoors, that's what I'd focus on, I charge in the garage or under an overhang.

 

[Betotap93]

If I understand correctly the battery you've bought is a welded cell pack so it probably won't fit the downtube cases you mention because they're a close fit to their chosen cell-holder layouts. Roll top panniers have the edge over frame bags for waterproofing, and to absorb local impact you can add rigid panels over the foam (like in the cell pack only more effective), then more foam to stabilise all that inside the bag. Liitokala cells aren't great quality so try to avoid taking the battery indoors, that's what I'd focus on, I charge in the garage or under an overhang.

Thanks a lot, for what i see a lot of people put this battery on to silverfish cases, the thing is a have a trek marlin 5, with no place for the silverfish, so maybe i was thinking putting it on the rack? i haven't seen silverfish batteries downtube.

What do you think? What worries me besides fallign and damaging the battery, is charging it outside like you say. So a case, will be more practical.

 

[saneagle]

Thanks a lot, for what i see a lot of people put this battery on to silverfish cases, the thing is a have a trek marlin 5, with no place for the silverfish, so maybe i was thinking putting it on the rack? i haven't seen silverfish batteries downtube.

What do you think? What worries me besides fallign and damaging the battery, is charging it outside like you say. So a case, will be more practical.

Your rack isn't the best design for a battery. it's going to hold it too high and too far back. If you're going to put a battery on a rack, it needs to be the opposite of that and 29" wheels don't help either. A silver fish battery might just fit in the triangle if you can make some suitable brackets. You'll have to make a cardboad template and check it.

 

[AntonyC]

It's best to work out details before ordering if you can, as you can see each option has its drawbacks. If a silverfish won't fit your triangle but the cell pack does with room to spare you could build a custom case, that may do better all round. For a 750W motor another thing to think about would be returning that battery or selling it to someone with a more suitable bike so that you can get a battery with less range but a case that fits.

 

[guerney]

What's the current limit of your BBS02? If it's this battery, max continuous discharge is only 20A. Can LiitoKala's claim be trusted?

https://vi.aliexpress.com/item/32995889825.html

 

[Betotap93]

It's best to work out details before ordering if you can, as you can see each option has its drawbacks. If a silverfish won't fit your triangle but the cell pack does with room to spare you could build a custom case, that may do better all round. For a 750W motor another thing to think about would be returning that battery or selling it to someone with a more suitable bike so that you can get a battery with less range but a case that fits.

As much as it hurts my pride, i think you are right. I will stick with the bag and foam and look for a permanent solution with less AH, but more secure. Like a downtube battery with a hailong case.

 

[Betotap93]

What's the current limit of your BBS02? If it's this battery, max continuous discharge is only 20A. Can LiitoKala's claim be trusted?

https://vi.aliexpress.com/item/32995889825.html

From what i know it is 25 a

This is my battery, liitokala claims 60a

LiitoKala 48V 25ah 21700 5000mAh 13S5P Lithium Battery Pack 48V 25AH 1500W electric bicycle battery Built in 30A BMS T/XT90/XT60

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

 

[guerney]

From what i know it is 25 a

This is my battery, liitokala claims 60a

LiitoKala 48V 25ah 21700 5000mAh 13S5P Lithium Battery Pack 48V 25AH 1500W electric bicycle battery Built in 30A BMS T/XT90/XT60

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

Had to use Google Translate, after setting location to "Chile", because the listing wouldn't display for the UK. 30A "Nominal", does that mean continuous?

Brand: LiitoKala Model: 48V 25Ah E-Bike Battery Cell: LiitoKala 21700 5000mAh () Category: Lithium-ion Battery Voltage: Peak 54.6V, Operating 48V Capacity: 25Ah Power: 150W-1000W Cut-off Voltage: 36.4V Max. Discharge Current: 60 Amps Max. Continuous Discharge Amperage: 30 Amps Nominal Discharge Amperage: 30 Amps Charging Current: <5 Amps Charging Voltage: 54.6 Volts Battery Cell: 21700 5000mAh 13S5P Battery Size: (300*115*75mm) ± 2mm Battery Weight: About 4.55 kg ± 0.1 kg Charging Temperature: 0–45°C Discharge Temperature: -20–60°C Storage Temperature: -20–65°C Battery Temperature Protection: 60°C plus 5°C Output and Parameters: High-current positive/negative connection column (red positive, black negative); Storage Time: At least 90% of remaining power within 6 months (recommended charging within 3 months) Battery Warranty: 12 months (parts and technical support are provided free of charge; customers must bear the appropriate logistics costs)

Time will tell if it turns out to be a false economy. Personally, I'd be ready to jump off and flee a burning BBS02 conversion at any time, charge and store this battery outside far from my home. Attempting safety by lowering the controller limit to 10A or something rather defeats the point of having a BBS02. The only cheap Chinese celled batteries I've seen on this forum (I've only been a visitor for 4 years) which haven't failed, have had low continuous amps drawn from them. Perhaps an actual battery expert will rock up and comment.

Please do keep us updated.

 

[Betotap93]

I dont know if this image help





There is one user on this forum who has the same battery, for 4 years. And i been looking for liitokalas users with bad experiencies, and there are a few, but not a lot like for example UPP.

Either way, this will be momentary and i be transitioning to a more reliable brand as soon as i can.