BMSBattery battery and lead Qs

[alban]

Planning on prob getting a 36V 16AH LiFePO4 from BMSBattery lifepo4-battery. I'm a heavy throttle user and, well, I'm just plain heavy too so I need Watts for range - just can't find a supplier here tho' Eclipsebikes do a 12AH one. Reasons are that they seem a reasonable if slow and 'poor at coms' supplier; LiFePO4 seems to give the best life if treated well; plug & play unlike LiPo; safer than LiPo to a novice; the 12 16AH Headway cells are higher C rate than Ping if I need to get more Amps later; cheaper than A123; meaty and few connections.
Cons are it's more expensive than Li-ion (approx £320 with charger & shipping so I'm taking a deep breath); 6.8Kgs; it's in China and I can't get an intelligible answer as to whether these are A or B grade Headway cells! I suspect B grade from E-S posts. Not sure what that really means...
Where's the glaring error in my reasoning?!

Would that weight be able to be put in a bar bag on a 20" MTB style folder without making the steering atrocious? The folder I intend getting has rear & front susp and I also don't want more weight at the rear to prevent wheelies.

Wondering if a kettle lead to attach batt to controller is OK as I had read of someone doing that. All the similar leads I can find are max 16A rated. As I may get a 25A draw with a new controller is it nevertheless OK to use such a lead or will I have to use higher rated cables?

It's all theoretical for now but I want to be as sure as poss about the route I'm taking.
Thanks for help received up to now and future help.
Having an eBike has revolutionised what I can do.

 

[Scottyf]

I think it's angood choice between plug and play, getting the right c rating and having lots of range.
576 total watts should give plenty of range. Controller depending but I'd at least expect 30 mile range at reasonable speeds.

Not sure if the cells are b grade. I wouldn't have thought so. Either way that size battery and chemistry should last years at everyday use.

6.8kg is quite heavy so it may hinder handling. But untill you get it and set it up or trail the weight with some potatoes in a bag to get an approximate feel would be a good check.

It's the weight of lifepo4 that puts me off a little and I doubt I'd need a life cycle of 1000 plus as I'd probably get bored and want to change something.

As long as you get indecent charger and connections like the single pole connectors you can also buy from Bms battery you should be ok!

 

[oigoi]

I think the bikes stability would not be good with that much weight if it was high up - you cold start weaving when you hit a bump for example.
The idea of doing a trial with some potatoes is a good one I would try riding the bike like that before spending a lot of money on a battery that would be unsuitable.
Would be be better to get the weight lower down somehow

 

[Deleted member 4366]

I've got a 20ah Ping battery that weighs 7kg on my rear rack with a BPM motor on the rear as well. I don't really notice the weight when riding compared with any other ebike, but the stability is a little compromised. It's a little twitchy when standing on the pedals and doesn't have the precise steering of my other bike with front motor. If you have a front motor, stability shouldn't be a problem. The 20aH Ping is good for 40amps peak, which is as much as you'll ever need. Pedaling at 20 mph uses about 10 amps, which goes up to about 25 amps up steep hills. With a Ping battery, you get full support and a good reputation. I'm pleased with mine, as now I can go a very long way (about 60 miles) with minimal effort. It's well worth considering one.

 

[alban]

Interesting that there have been a few Qs recently about these batts. Ping is good but appreciably more expensive for 20AH and I may need that AH for 2C (40A). Apparently with a mod by Doctorbass (E-S forums) on Ping's recs you can get 3C (cooling the mosfets by soldering copper plate to them - but that's a wee bit advanced for me! Doctorbass). Headways seem good for 3-5C. I'm torn as there's no support from BMSBattery I suspect but then the Headway pack may be easier to tinker with as it's screwed together. 15Ah X A123 from the reliable Cell-man seems too much money when it's for leisure only. If I want range, safety, power and longevity LiFePO4 seems the way to go with all its weight.
I need a batt that I can try on my Cyclamatic but also convert to a 20" wheel folder if not enough of a climber off road. 7 Kgs in a bar bag on the Cyclamatic seemed OK but that was on the road. The folder (haven't got it yet but will have rear susp and so a rack is difficult as well as increasing the wheelie tendency)?
I was concerned that with a front motor I might lose traction on loose surfaces up hills which is where I need the power.
I think I'll get power cables designed for 25A rather than trust a kettle lead....

 

[Deleted member 4366]

Alarm bells starting to go off when I hear things like Cyclamatic and 20" folder and 40 amps at the same time.

 

[Scottyf]

What are you building that requires 40amp ?

I didn't like the bpm with a large battery on a rack on the rear. It made high speed cornering skittish on 35c road tires. It up set the balance on a road bike by quite a bit.

 

[alban]

No need to worry really my self-preservation instinct is still strong!
Set up mainly for slow unextreme off-road excursions. Yes I want to try the batt on the Cyclamatic at 25A and if that's OK all well and good. I'd like the ability to increase beyond that in the unlikely event I need it and it's stable but I'm aiming at 25A max. The folder is another thought again at 25A max. Sturdy steel frame, rear motor, torque bars etc. I want a batt that covers all eventualities.

 

[Deleted member 4366]

OK that makes sense. Now you have to decide. A 20ah battery is a big heavy thing, but can supply 20 amps continuously and more if required for short periods. A 15ah is lighter but gives less current. Pings are lighter than most lifopo4s but expensive. LiCoMn are cheaper and lighter but don't last so long. Lipos are cheaper and lighter still and can provide as much current as you want but are more tricky to charge and not as safe. Life would be a lot easier if we didn't have choices!

 

[alban]

Yep - I've reached the paralysis of analysis stage (with emphasis on the 'anal')! Sending hundreds of pounds to unknown bods in China makes my palms sweaty when there's little comeback. It's not so much the money as the hassle of getting something wrong so that it doesn't all hang together... However I do have my Engineering graduate son at home for a few weeks to help his technically challenged dad out. I'm now so bored with the process I'll probably make a decision!
Thanks for all the patient explanation.

 

[banbury frank]

Hi the 15 ah 36 volt from BMS is fine only 3.5 kilos

20 amp continuous bms 40 a peak

Best you will get . pay with paypal allow up to 6 weeks for delivery

36V 15Ah Li-Ion Shrink Tube EBike Battery Pack - BMSBATTERY

will fit nice in bar bag


Frank

 

[alban]

Hi Frank
Thanks. So have you used a few of these particular batts then from BMSBattery? You've found the company OK if a bit slow? I was dubious that the Li-ion 15AH could sustain 25A for long without being damaged. The weight and price are very temptng. Aha more indecision...!

 

[banbury frank]

Hi I can recommend it as have tried one on a 33Amp controller NO cutting out

we used to Buy direct from the same supplier in china that BMS use

we only use 48 volt But there 36 volt is OK we use 33Amp controllers and the BMS don't cut Out at continues flat out 30 MPH


we have decided on our new model for next year to only use 48 volt 10AH battery's our new bikes will have battery and controllers in triangle case in frame with space on the rear rack for a second battery for long range 20 miles NO pedaling

Frank