LITHIUM ION BATTERY

Hi just bought a LiPo battery from Aliexpress,  on the site it states 9 amp hour but when i took it into work last night and tested it it it was only 1.5 amo hour ,so I'm returning it to them , but most of these Li Po batteries all seem to have low Amp Hours even the very expensive ones ,I would have thought this would have a really bad effect in the capacity to restart after a few attempts? 
any thoughts or has anyone else used thes with good results , far lighter than lead acid or AGM batteries. 
Thanks again Phil 

The Amp/Hour is (within reason) less critical than the CCA (cold cranking amps) when it comes to starting however if you choose to go the "lithium" route "DON'T BUY CHEAP" and install a 30amp fuse between the RR and the battery also ensure the RR (regulator/rectifier) you have is lithium compatible (check out "skidmark's" thread about how his garage burnt down as a result of a lithium battery fire relating to a power tool left on charge) lithium fires are almost impossible to extinguish unless you can access the battery to cool it !!!

Hi yes I've seen a few videos of these on fire it's frightening to watch  , but they weigh practically nothing compared to lead acid , and also I'm trying to hide the battery, and have it on its side so only a gel would be a alternative,  but they still weigh a lot , the battery i bought from Aliexpress wasn't exactly cheap,  a little bit more than a good lead acid battery bought here in the UK around £50, I know that's cheaper compared  to others though , but to state 9amp and actually being 1.5amp  is shocking isn't it .
I'll  take note of fitting a higher rated fuse in between,  don' t really know how I'm going to see if the R/R wil be ok though,  its just the original one fitted.
Thanks again for your help 
Phil

philmountains wrote:

Hi yes I've seen a few videos of these on fire it's frightening to watch  , but they weigh practically nothing compared to lead acid , and also I'm trying to hide the battery, and have it on its side so only a gel would be a alternative,  but they still weigh a lot , the battery i bought from Aliexpress wasn't exactly cheap,  a little bit more than a good lead acid battery bought here in the UK around £50, I know that's cheaper compared  to others though , but to state 9amp and actually being 1.5amp  is shocking isn't it . Yes it is
I'll  take note of fitting a higher rated fuse in between as I understand it the RR output isn't fused on your bike, the later 750 was ,  don' t really know how I'm going to see if the R/R wil be ok though,  its just the original one fitted. If it's the stock 1980 RR it is unlikely to be suitable (somebody like Ricks would be able to advise) lithium needs a "stable" output voltage
Thanks again for your help 
Phil

slmjim here.

Curious how you tested capacity?

I have a minor hobby of high performance LED  & LEP flashlights.  LiIon cells in common 18650 and 21700 size formats, among others. are ubiquitous in that arena.  LiIon capacity testing is a much-discussed subject.

The standard way of establishing cell capacity (Ah) is by using a relatively-sophisticated analyzing charger.  That's a device that calculates cell capacity in Ah or, less commonly, mWh, by cycling the cell through repeated charge / discharge cycles.  A cell is charged to a pre-set maximum voltage, then discharged down to a preset minimum voltage into a known load at a known rate in Amps (A) or a fraction thereove in milliamps (mA).  The charge / discharge cycle repeats for a preset number of times, with the analyzing charger monitoring & storing the amount of energy needed to repeatedly charge the cell and, the amount of energy that was dissipated into the known load during discharge.  It then displays the calculated capacity of the cell in Ah or mAh.

1.5 Ah is mediocre performance for a single 18650 cell.  I'd expect at least 6 times that for a nominal-12V battery.

Then there's the fact that a LiIon battery should have a charging system designed specifically for a LiIon battery, that monitors both voltage and current for correct & safe charge termination.

A known issue with LiIon batteries is their reduced power availability when cold.  A common suggestion in some modern bike forums is to turn on the headlight for 30 ~ 60 seconds prior to cranking, to allow the battery to warm internally, reducing internal resistance & increasing available CCA's.

A LiIon cell / battery isn't to be trifled with.  They can be permanently damaged & made unsafe by overcharging and, discharging below a certain threshold.  No way I'd run a LiIon battery on an old bike that was designed for a lead acid battery.  Suggest keeping the bike away from structures if a LiIon battery is installed.  A LiIon fire is not only difficult to extinguish, the byproducts of LiIon combustion are very toxic.

The failures of AliEx is a common point of discussion in the LED and LEP communities, regarding, but not limited to, LiIon cells.  Outright counterfeits from sketchy vendors are common, as are factory rejects & used cells that may not be safe.  The Chinese aren't our friends in this respect; there's no accountability when buying from AliEx and it's ilk.

Good Ridin'
slmjim

I have no love for these types of batteries. From what I've seen they don't last and are dangerous. 

slmjim+Z1BEBE wrote:

slmjim here.

Curious how you tested capacity?

 

For motorcycle batteries, I use a 60w headlight bulb. In thery,a 10ah battery should last 2 hours. I don't want to complety drain the battery, so at 50% of rated ah, I end the test and consider the battery good,

Hi thanks for your detailed explanation,  I'm rethinking this whole lipo battery idea now, but still want to reduce the size of the battery someway , if I'm using all LED , shouldn't it be possible to reduce the Amp hour capacity, thus a smaller battery? Or do i need 12amp hour to start the bike, sorry if this all sounds stupid, I'm no electrician LOL.
oh I tested the battery straight out of the box at work they have a dedicated charger/ tester there. 
​there.
Thanks again Phil 
oh also I'm thinking about getting a new regulator/rectifier as Wookie mentioned, its a old bike now, and I've had experience of electric failure and being stranded by the road on much more modern bikes. 
Tonights cock up has been taking the front brake master apart and ripping the diaphragm, oh don't you just love it when a plan goes your way 😅

philmountains wrote:

Hi thanks for your detailed explanation,  I'm rethinking this whole lipo battery idea now, but still want to reduce the size of the battery someway , if I'm using all LED , shouldn't it be possible to reduce the Amp hour capacity, thus a smaller battery? What lighting you run is largely immaterial to battery capacity (unless you plan to leave them on when parked) given that once running the whole elec system should be running from the generator with the surplus topping up that battery Or do i need 12amp hour to start the bike, sorry if this all sounds stupid, I'm no electrician LOL. What does the manual say, CCA is more important for starting but reducing the battery capacity will mean it needs to start pretty quickly and don't stall.
oh I tested the battery straight out of the box at work they have a dedicated charger/ tester there. 
​there.
Thanks again Phil 
oh also I'm thinking about getting a new regulator/rectifier as Wookie mentioned, its a old bike now, and I've had experience of electric failure and being stranded by the road on much more modern bikes. 
Tonights cock up has been taking the front brake master apart and ripping the diaphragm, oh don't you just love it when a plan goes your way 😅

I own two motorcycles, and both had lithium Ion batteries with/out any problems for years.     Every time consistently they are are about 13 VDC before running (have voltmeter in one bike),...and boy, they are so light like empty plastic boxes (no lead).

I have equipped the bikes with Shindengen SH775 and SH847 respectively though,......for constant recharging voltage.     These batteriy technology is what has made electric cars again contenders as commuters.....and electric bicycles also. 

 

There has been much discussion of these matters over at the ZRXOA. It could be worth your time to read a bunch of those threads. 
As I recall, there was a bit of a consensus there that the LIFePo (lithium iron) batteries are a better choice for this application.