Rebuilding a Frog style Battery

[motomech]

Why do you assume they are LifePo4 ?
I cannot imagine any Lifepo4 cells holding 4.17 volts so consistently without overheating , bloating, etc.
..and the BMS should prevent overcharging anyway.
So, im guessing they are lipo.
But you need to do those load tests to see what is going on

LiPo is NOT battery chemistry.

A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated variously as LiPo, LIP, Li-poly and others), is a rechargeable battery of lithium-ion technology in a pouch format. Unlike cylindrical and prismatic cells, LiPos come in a soft package or pouch, which makes them lighter but also less rigid.

https://en.wikipedia.org/wiki/Lithium_polymer_battery

LiPo is NOT battery chemistry.

We KNOW that.
But it's so universally used that you are not going to change the vernacular.

 

[jimmyN]

https://endless-sphere.com/forums/viewtopic.php?f=2&t=53796&p=800677&hilit=frog+case+lipo#p800677

Excellent, thanks for the info. I'll look into these.

 

[LewTwo]

LiPo is NOT battery chemistry.

We KNOW that.
But it's so universally used that you are not going to change the vernacular.

I can try .... particular when one uses in comparison to another battery chemistry such as 'Lifepo4'. While I am at it 'aluminum' is an 'alloy'. Alloy is not aluminum.

 

[motomech]

Then you need to learn to handle LiPoly, as there would not be a BMS(Battery Management System).
But two bricks(What is called 12S/1P, two 6 cell bricks in series w/ no additional parallel)is fairly easy to charge, but you will need a special charger.
What is interesting about what Dave(D8veh) did, is how snugly they fit in that case. That's 8,000 mAh of strong (46V) power which on most Ebikes would be about 15 miles.
Not possible to get that much battery in that little case w/ any other type of battery.
I will take a look at what batteries are that size(physical diamensions), their availability and what they cost and get back w/ you.

 

[motomech]

As I suspected, those Flightmax batteries are no longer available.
Your best bet would be the MultiStar 6S/8000mAh batteries. They are slightly smaller;
https://hobbyking.com/en_us/multistar-high-capacity-6s-8000mah-multi-rotor-lipo-pack.html
I can't tell which warehouse to ck. because you haven't filled out your profile.

 

[Hillhater]

not being picky but, i think D8veh only had 8 Ahr of 12 s Zippys in that pack.
you may be better trying the Multistar packs.
Still dont know if it is the cells or the BMS that is faulty in the original packs though.
Load tests ???

 

[motomech]

not being picky but, i think D8veh only had 8 Ahr of 12 s Zippys in that pack.
you may be better trying the Multistar packs.
Still dont know if it is the cells or the BMS that is faulty in the original packs though.
Load tests ???

Oh yeah, you are right, I get too excited over LiPoly

 

[jimmyN]

Thanks so much for the input, I have lot better understanding. I hope to do the load test tomorrow and report back.

 

[jimmyN]

What do you think about this?
https://www.aliexpress.com/item/Electric-Bike-48V-12Ah-Lithium-ion-Frog-Battery-by-samsung-cells-with-charger-for-48V/32460545716.html?spm=2114.40010508.4.19.e34Dr1

 

[greg176]

I think you would be much better off with a shark pack from Lunacycle. How many amps does your bike need ?

 

[jimmyN]

15 or 20 should do it

 

[jimmyN]

does it make sense to build a pack? other than the flexibility to create odd shapes. seems like after buying the components and finding a spot welder there won't be much of a savings, am I missing something? is there a lot of people building custom packs?

 

[motomech]

Actually, I looked again and the MultiStar options for that case is even better than I thought.

The Zippy Flightmax spec.s are;
165x69x52mm

And MultiStar 6S/10,000mAh($106) spec.s
168x69x54mm
Close enough they will fit.
WOW, 10 Ah's for $212 plus freight!
I think I'm going to build a Frog case pack even though I don't really have a use for it,....yet.

 

[jimmyN]

Actually, I looked again and the MultiStar options for that case is even better than I thought.

The Zippy Flightmax spec.s are;
165x69x52mm

And MultiStar 6S/10,000mAh($106) spec.s
168x69x54mm
Close enough they will fit.
WOW, 10 Ah's for $212 plus freight!
I think I'm going to build a Frog case pack even though I don't really have a use for it,....yet.

So there is no problem connecting these packs in series to get the voltage I want? I take it they do not have a BMS?