Hillhater
100 TW
Random thinking here, so stick with me a little...
We know 18650's are the go for light weight and compact size.
But, they leave something to be desired in the discharge ability (power) , voltage sag, and cost areas (if you want the powerful ones )
I guess most of us understand the "Hybrid" pack principle of parallel connecting a high discharge pack (lipo or ultra cap), with a similar capacity , but poor discharge ability, pack of lifepo4 or similar.
So a hybrid pack of Lipo and 18650 should be no problem ?
The voltages will obviously need to be equal...but here is the killer question......do they actually need to be the same capacity (Ahr) in each chemistry ?
EG could it work with a 5Ahr Lipo , and 20 Ahr of cheap (low power) 18650's ?...both at say 36 volts.
The theory being, that the 40c Lipo would feed the peak current surges during acceleration etc, and as its voltage falls with capacity drain, the parallel 18650 pack would "recharge " the Lipo by balancing the voltages between the packs ?
My logic is that you can buy capacity (Ahr) in 18650 very cheap, but any reasonable discharge rated 18650 is either lower capacity or expensive, often both !
So, first question is, what problems paralleling 2 packs of same voltage but different capacity and discharge rating ?
We know 18650's are the go for light weight and compact size.
But, they leave something to be desired in the discharge ability (power) , voltage sag, and cost areas (if you want the powerful ones )
I guess most of us understand the "Hybrid" pack principle of parallel connecting a high discharge pack (lipo or ultra cap), with a similar capacity , but poor discharge ability, pack of lifepo4 or similar.
So a hybrid pack of Lipo and 18650 should be no problem ?
The voltages will obviously need to be equal...but here is the killer question......do they actually need to be the same capacity (Ahr) in each chemistry ?
EG could it work with a 5Ahr Lipo , and 20 Ahr of cheap (low power) 18650's ?...both at say 36 volts.
The theory being, that the 40c Lipo would feed the peak current surges during acceleration etc, and as its voltage falls with capacity drain, the parallel 18650 pack would "recharge " the Lipo by balancing the voltages between the packs ?
My logic is that you can buy capacity (Ahr) in 18650 very cheap, but any reasonable discharge rated 18650 is either lower capacity or expensive, often both !
So, first question is, what problems paralleling 2 packs of same voltage but different capacity and discharge rating ?