Battery life

WheezyRider

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  • ensure by what ever means that your charger is not over charging the battery
Yamaha Charger. No

Generic Chinese Chargers No although a timer plug used to cut mains power after a given amount of time
  • there are benefits to charging to less than the max 4.2v per cell
Yamaha Charger No/unknown.

Generic Chinese Charger No although a crude partial charge could be given by using the timer plug to cut power before a full charge is reached.
  • slower charging is beneficial compared to faster charging (all related to the 'C' of the battery cells)
Yamaha Charger believed to be 3.6A.

Generic Chinese Charger believed to be 2A
  • and ditto dis-charge rates (as in beating the ** out of the motor/battery vs more gentler power assist)
Yamaha ridden 12/16 miles to work in lowest assist eco offering 100% support, and off, no support, using 25% to 35% of batteries capacity. Battery charged back to full at work and then ridden 10 miles home on the road using mostly lowest support eco offering 100% support, and occasional middle assist offering 190% support to maintain speed over/up steeper hills, and occasional no support for steeper downhill gradients, using mostly 40% of the batteries capacity but up to 50% depending on conditions. Battery then removed and stored in the house.

Rear hub bikes with silverfish 15Ah batteries ridden on short shopping trips, other general errands, and also 20 mile return road trips to work where the battery was charged at work before the ride home. Generally ridden using maximum assist, and an average speed for the rides to and from work around 19mph. After any ride irrespective of length the battery was put on charge using a timer plug.
  • don't fully discharge your battery. In fact it seems that within limits the less you discharge the battery before re-charging, the more 'full discharge cycles' you'll get
Yamaha almost never discharged below 50% during its life as a commuting vehicle.

Silverfish batteries more deeply discharged
  • don't leave your battery stored for prolonged periods at fully charged levels nor store it at high temperatures (e.g. 30degC)
Yamaha battery stored mostly at close to 60% charged and never left for prolonged periods fully charged and stored inside the house.

Silverfish batteries much more often left fully charged and left on the bikes in an unheated brick garage.

  • if your battery allows it, monitor each cell stack to keep an eye on balancing (in case your BMS screws up)
No monitoring for any of my batteries

I think my Yamaha battery has lasted so well despite the relatively high mileage I have ridden as in its commuting role it was used very regularly, hardly ever discharged below 50%, hardly ever spend much time fully charged before being ridden, and stored inside the house. The cost of a replacement battery is a powerful tool in battery care! By luck my commuting distance was just right for the capacity of my battery and the way I used it.

Don't know if I've just missed it, (thread has got so long now!) or it wasn't mentioned, how long did the Silverfish last?
 

guerney

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The battery was a spare one kept in a wp pannier along with the coke.
I think the BMS likely failed , how I don't know but he mangaed to post it back to bosh who simply binned it.
The recipe of coke is secret, who knows what electrically problematic elements it contains? Such a waste of cells and coke.
 

Nealh

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A waste cells cetainly as for coke, I's sooner drink dish water.
 
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guerney

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A waste cells cetainly as for coke, I's sooner drink dish water.
That could be one of it's secret ingredients. Coke of old tasted far nicer, fructose is too sweet and tastes wrong. Coke makde with cane sugar isn't generally available in the UK, not cheaply anyway.
 

guerney

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I had dropped a power bank containing 18650 cells (I think - maybe four) somewhere in my garden three weeks ago, and finally found it yesterday - it's been rained on for three weeks :eek: It's waterproof if the flap over the ports is closed, and still works, but the USB ports have rusted, because I had left a cable attached and the flap over the ports was open. The ports were pointed downwards, luckily. It charges and discharges ok, but I may have to replace the ports.
There's definitely moisture inside the case of the USB power bank, which I'd lost and left in rain for three weeks - it's condensing behind the bulb cover, after being warmed by charging. The case is likely glued shut, so I'll try to open it perhaps using a heat gun and see if any cells look damaged.

49709
 

guerney

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It wasn't glued, but hard to prise open with spudgers, after finding the right sized star drive, contains DBK INR2 cells (whatever those are). I can't open it any further. The cells look ok, the unit seems to be working fine apart from charge staus LEDs at the front being switched on and off every five minutes, which may be indicating some sort of error, because that's not what it used to do. Water droplets are visible. Maybe it just needs slow and gentle drying out in a warm room for a few days? I may chuck this away, to be on the safe side...

49710
 
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soundwave

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guerney

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That's a good idea, but it turns out there are only three cells. Front status LEDs switch on and off every five minutes exactly, there must be an error. The handiest, most gentle slow heating method is by placing it on a warm amplifier top grille, which is where it will stay for a few hours... and then in a metal wheelbarrow while I'm sleeping. If the lights stop flashing on and off every five minutes, perhaps it could be safe to use? Mind you, corrosion must be everywhere...

Safer sodium-ion batteries can't arrive soon enough IMHO. If a large manufacturer like BYD are making cars with sodium-ion batteries, chances are cells may become available for consumers soon?

 

soundwave

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i dont even bother trying to fix those things as the pcb will have a short or just be cheap crap but if you can get hold of a few dead ones and dig the cells out there still usable but id get a separate charger.

nice sharp nips helps rip off the nickle spot welds.
 
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guerney

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i dont even bother trying to fix those things as the pcb will have a short or just be cheap crap but if you can get hold of a few dead ones and dig the cells out there still usable but id get a separate charger.

nice sharp nips helps rip off the nickle spot welds.
If it doesn't dry out and the LED status lights don't stop showing an error, I'll cut out the cells and might try them in something like this 3X 18650 cell case:

 

soundwave

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the other pack can do 5v 2A and 8.4v 9A via the barrel connector you can charge it via this with a 8.4v adaptor but it does not balance the cells unless you swap them around.

there is also no short circuit protection so if you put in a cell the wrong way round the springs melt :p
 
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soundwave

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guerney

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you can charge and capacity test most cell with one of those but you need a 5a 9v adaptor.
It's only been on my amplifier grille for just under an hour, but the blue LED staus lights are showing much less frequently - this power bank may be drying out! In a few hours, I'll have a good look to see if there is corrosion on the steel strips connecting the cells, which is the sort of worrying feature which could make this power bank suddenly unsafe at some point in the future. If possible, I'll also measure cell voltages, because I expect this cheap power bank does not contain a balancing BMS.
 
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soundwave

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that's the thing they dont balance charge so if one cell gets out of whack it just kills them but cheap enough i used to get them from pound land and just rip the cells out of them for lights.

tho some times the capacity stated on the cell is no where near what is on the label but never had one with more than 2500mah.

tho id never use any of these cells to make a pack for a ebike but there ok for lights ect
 
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guerney

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that's the thing they dont balance charge so if one cell gets out of whack it just kills them but cheap enough
Things aren't made to last these days.

'My fridge is 60 years old' – the appliances that just go on and on

A 38-year-old microwave and 45-year-old Moulinex mixer are just some of the household treasures we have found that refuse to give up the ghost



It couldn't have cost them much to use a balancing BMS and manufacture a longer lasting product.
 

soundwave

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49711

:p
 

georgehenry

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Don't know if I've just missed it, (thread has got so long now!) or it wasn't mentioned, how long did the Silverfish last?
Hi, the first three paragraphs in my post #74 in page 4 of this thread talk about my silverfish batteries.

The most surprising experience I had with a silverfish battery was the one that came with a second hand Oxygen Emate of probably 2011 vintage I bought for £100. I originally bought it for spars for an Oxygen Emate I already owned and assumed the battery was dead. But after deciding to get the bike going as it was in remarkably good nick and using one of my own silverfish batteries I decided to see if there was any life in it and charged it for a number of hours, and it came back to life and still works now. After a few local rides to check how it held up I started using it to commute 10 miles to work on a route with some hills using max assist and a 20 mph cut off, so it had to work hard, and it managed that.

https://www.pedelecs.co.uk/forum/threads/the-tale-of-a-£100-second-hand-electric-bike.33079/
 
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WheezyRider

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Hi, the first three paragraphs in my post #74 in page 4 of this thread talk about my silverfish batteries.

The most surprising experience I had with a silverfish battery was the one that came with a second hand Oxygen Emate of probably 2011 vintage I bought for £100. I originally bought it for spars for an Oxygen Emate I already owned and assumed the battery was dead. But after deciding to get the bike going as it was in remarkably good nick and using one of my own silverfish batteries I decided to see if there was any life in it and charged it for a number of hours, and it came back to life and still works now. After a few local rides to check how it held up I started using it to commute 10 miles to work on a route with some hills using max assist and a 20 mph cut off, so it had to work hard, and it managed that.

https://www.pedelecs.co.uk/forum/threads/the-tale-of-a-£100-second-hand-electric-bike.33079/
Ah, I see, they are still going. I didn't think I'd seen you mention their demise, but just sounded like it from your previous post :)
 

egroover

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It wasn't glued, but hard to prise open with spudgers, after finding the right sized star drive, contains DBK INR2 cells (whatever those are). I can't open it any further. The cells look ok, the unit seems to be working fine apart from charge staus LEDs at the front being switched on and off every five minutes, which may be indicating some sort of error, because that's not what it used to do. Water droplets are visible. Maybe it just needs slow and gentle drying out in a warm room for a few days? I may chuck this away, to be on the safe side...

View attachment 49710
Risk burning your house down charging a damaged powerbank to save spending £8 on a replacement ? I can see the Daily Mail headline already
 
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