New Battery

[Deleted member 4366]

I bought this 20aH 36v battery from BMSBattery for my Giant with BPM motor, which needs a strong battery because the controller's set to 30 amps for effortless hill-climbing. It worked out at just under £250 including shipping and the £13 duty etc. The weight is 4.8 kg, which is less than the Ping battery I had on it before.

36V 20Ah Li-Ion Shrink Tube EBike Battery Pack - BMSBATTERY

I tested it today on a nice ride in the sunshine, and it's impressive. With no conditioning charges, i.e. just charged up first time, I used 16.2 aH, and in the last hill just before my house, it was still giving 30 amps without complaint, and showing a sag of only 2v approx. When I got home, it was still showing 37.4v, so should be good for a few more aH.

It's not that large and not too wide, so would fit nicely in the frame triangle, which is what i plan for it. My rating: 20ah for £250 - bargain!

 

[cwah]

Sorry D8veh, I see it differently:

For £50 and 1 kg more, you can get a 36V20AH A123 pack shipped:
A123 36V20AH(12s1p) lifepo4 battery pack electric vehicle with charger - Detailed info for A123 36V20AH(12s1p) lifepo4 battery pack electric vehicle with charger,36V20AH lifepo4 battery pack,A123 36V20AH(12s1p) lifepo4 battery pack electric vehicle w

or here:
36V20AH A123 20AH 12S1P(720Wh),A123 20AH Pack,lifepo4 36V20AH(A123 system) battery pack for Scooter free shipping-in Battery Packs from Electrical Equipment & Supplies on Aliexpress.com


I purchased my one (66V20AH) from Victpower and it's still going strong.


I would rather invest in these battery as they are rated for much more than 800 cycles, have a much better shelf life and is able to pull over 200A.


The only complain I'd have is that they come from the black market (unsold cells/manufacturing defect from A123) and only have around 18.5AH usable. However so far most people are happy with these cells.

 

[morphix]

I bought this 20aH 36v battery from BMSBattery for my Giant with BPM motor, which needs a strong battery because the controller's set to 30 amps for effortless hill-climbing. It worked out at just under £250 including shipping and the £13 duty etc. The weight is 4.8 kg, which is less than the Ping battery I had on it before.

36V 20Ah Li-Ion Shrink Tube EBike Battery Pack - BMSBATTERY

I tested it today on a nice ride in the sunshine, and it's impressive. With no conditioning charges, i.e. just charged up first time, I used 16.2 aH, and in the last hill just before my house, it was still giving 30 amps without complaint, and showing a sag of only 2v approx. When I got home, it was still showing 37.4v, so should be good for a few more aH.

It's not that large and not too wide, so would fit nicely in the frame triangle, which is what i plan for it. My rating: 20ah for £250 - bargain!

Great price d8veh, I have the same style battery from BMS but half the current rating (10Ah) and mine cost £130 with shipping and a bit of VAT. It weighs 2.3kg. It's still working great after 18 months.

I've just been looking at these Turnigy 11.1v / 2200mAh Lipo batteries (185g) from HobbyKing. $7.95 each.. now they have a UK distribution centre that's much better cheap delivery and no duty... I don't know much about Lipo batteries but I'm wondering if they might be a good choice for small wheel builds...

Might it be possible to do 2x4 packs to get 36v?.. that would be a very low weight and cost ratio.

I wonder how well these batteries perform compared to Li-Ion?

 

[cwah]

Morphix, this lipo pack is cheap but too low on capacity. You probably don't want to use it for ebike as it has only 11.1V*2.2AH=24.42WH.

So to have an equivalent energy of a 36V10AH pack, you would need 360/24= 15 pack to harness in order to make it work. Imagine pluggin together 15 battery how messy it would be!

You need to find at least pack that are twice or tripple the size of this pack for your ebike to make it work.

 

[Deleted member 4366]

Great price d8veh, I have the same style battery from BMS but half the current rating (10Ah) and mine cost £130 with shipping and a bit of VAT. It weighs 2.3kg. It's still working great after 18 months.

I've just been looking at these Turnigy 11.1v / 2200mAh Lipo batteries (185g) from HobbyKing. $7.95 each.. now they have a UK distribution centre that's much better cheap delivery and no duty... I don't know much about Lipo batteries but I'm wondering if they might be a good choice for small wheel builds...

Might it be possible to do 2x4 packs to get 36v?.. that would be a very low weight and cost ratio.

I wonder how well these batteries perform compared to Li-Ion?

Cwah's right. You'd be better off with a pair of the 22v 8000maH ones.

 

[morphix]

Morphix, this lipo pack is cheap but too low on capacity. You probably don't want to use it for ebike as it has only 11.1V*2.2AH=24.42WH.

So to have an equivalent energy of a 36V10AH pack, you would need 360/24= 15 pack to harness in order to make it work. Imagine pluggin together 15 battery how messy it would be!

You need to find at least pack that are twice or tripple the size of this pack for your ebike to make it work.

Ah. That's a non-starter then heh. I'll have another look and see if there's anything like that..I would only do it if there's a major weight advantage cuz these LiPo's make me a bit nervous and I'm not sure I can be doing with all this monitoring of the voltage under load and load balancing charging palaver.

I suppose I could just go for bottle battery or something small than 10Ah...I do have a LiFePo4 5Ah which is one of a set of two I bought..the first one performed very good on my 26" folder but died suddenly after 9 months...the second one I still have but it was never as powerful as the first one...and it's sat unused for a year and uncharged, so it may be useless now.. it was fully charged though when I put it to bed.. I will try it out later if I get chance.

 

[Deleted member 4366]

The oproblem with small batteries is their discharge rates. 10aH of KifePO4 or cheapo Li-ion is about as small as you can go for 15 amps. Afterthat, theoptions become more expensive and heavier (peraH).

 

[morphix]

I don't think I will worry too much then about the battery/carry weight on my next builds as there is always going to be a trade off as you say, between performance and carry weight.... if I were commuting by train I might look at sub-10Ah. For me 10Ah feels a good minimum Li-Ion battery, I can do my 5 mile round-trip to the sorting office entirely on throttle with it at full power.

I will take the same approach as Jerry on my next build with everything in the bag that just lifts on and off the rack.. the problem I had with my 26" was that everything was in the handlebar and I never got round to making a quick-release setup so it added significantly to the carry weight up and down two flights of stairs!

This time around, I can just carry the commuter bag with everything in, drop it downstairs and bring the bike separately.

 

[Deleted member 4366]

Just to complete the story. it's now showing 19.54aH on my Cycle Analyst and it's syill going strong, so I can say with a degree of certainty that it would go past 20aH; however, I don't like deep discharging my batteries, so I'm going to charge it up now.

It's still showing 36.5v and going down to about 34.5v under heavy load.