Batteries Charging Routine
- Thread starter Az.
- Start date
Eureka! I have found my early warning system! Upon detection of melt or cheesy wafts, chuck battery out of window.
" The melting point of cream cheese lies between 130°F (54°C) and 140°F (60°C)"
Will Cream Cheese Melt?
Will cream cheese cooperate when introduced to heat, or will it become a curdled mess?
www.darkcheese.com
For a safety clip perhaps? (see vid)
I'd be less worried about a handful of cells in a small tool battery bursting into flames, than a big block of 30+.
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While charging, again... and again no details about battery, charger, bike etc.
" The horrendous blaze looked 'like a rocket hit the house and blew up'. Tragically, the fire completely destroyed a family's house and resulted in a member of the family losing their life. "
"The brigade was called at 6.56am and the fire was under control by 9.22am"
North London dad dies after battery pack charging e-bike caused fire like a 'rocket hit house and blew up'
www.mylondon.news
" The horrendous blaze looked 'like a rocket hit the house and blew up'. Tragically, the fire completely destroyed a family's house and resulted in a member of the family losing their life. "
"The brigade was called at 6.56am and the fire was under control by 9.22am"
North London dad dies after battery pack charging e-bike caused fire like a 'rocket hit house and blew up'
Dad dies after battery pack charging e-bike explodes like 'rocket hit house'
Five people managed to escape the house before fire crews arrived
www.mylondon.news
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One of the reasons for the lack of detail on such incidents is reported in the "esf_batterybreakdown_report_2023_v7_-final" report, which is well worth a read;
https://www.electricalsafetyfirst.org.uk/media/sgyikuwb/esf_batterybreakdown_report_2023_v7_-final.pdf
"The Incident Recording System (IRS) is a national data
collection system, which collects detailed information
on all incidents attended by fire and rescue services
(FRSs). The IRS enables data on all incidents attended
by the UK FRSs to be collected electronically and
verified at source. This significantly improves the
timeliness and accuracy of data compared to the
paper-based ‘FDR1’ form collection process used
in the past.
However, the quality of the fire data
recorded at national level does not allow fires to
be attributed specifically to lithium-ion batteries,
e-scooters or e-bikes: the IRS currently has no
‘e-scooter’ or ‘e-bike’ category. Firefighters must
record that a fire involving one of these vehicles in an
open text box field. Information entered in an open
text box field does not appear in the publicly available
fire statistics published by the Home Office.
Such deficiencies in the IRS are hampering
developments in fire prevention strategies required
to mitigate fires from lithium-ion batteries. These
deficiencies need to be addressed as a priority."
Text box inputs aren't ideal for stats, but not impossible to work with. Let's hope when the government gets around to commissioning additional categorisations and options for data entry, they don't lump all do-it-yourselfer conversions into one checkbox... but since there is nobody representing the interests of the conversion crowd...
Trouble is, the time between done and over done is a little short...
I acquired a little biofeedback/relaxation device many years ago, and it makes geiger counter-like clicking noises, which indicates resistance of electrical current through the skin (lower resitance = more relaxed, less rapid clicking), detected via two electrodes placed on adjacent two fingers of one hand - it could detect lowering electrical resistance in cream cheese as it melts (the clicking noises would be spaced further apart in terms of time), which could alert me to throw the battery out of the window using the long handled pizza paddle.
E-Bike Battery Guide
This thread is dedicated for helping new E-bike owners to understand and maintain their batteries in the best possible way. There is a lot of confusion for any new E-bike owner as to how one should treat their batteries: Shop owners may say one thing, online resources may another thing, someone...
forums.electricbikereview.com
All good in theory, but very bad in practice unless you have a BMS that doesn't top balancing. What you guys and the guy that posted that thread are not getting is that the idea of 80% charging is for individual cells. You have a battery that is managed by a BMS. The BMS can't work with consistent 80% charging. If you want to prolong the life of your battery by charging to 80%, you must fit a special BMS, the price of which, along with the charger, will wipe out all the savings you made from getting longer life out of your battery.E-Bike Battery Guide
This thread is dedicated for helping new E-bike owners to understand and maintain their batteries in the best possible way. There is a lot of confusion for any new E-bike owner as to how one should treat their batteries: Shop owners may say one thing, online resources may another thing, someone...
As I keep saying, there's a reason that Bosch, Shimano, Yamaha, Pansonic, Bafang, every European and Chinese ebike manufacturer and every other ebike and battery manufacturer all charge their 36v batteries 100% to 42.0v Some guy on the internet who sells special chargers called Battery University or Grin tells you that they're all wrong.
How far can you trust that guy, who also wrote in that thread that it's OK to charge your battery at 0.5C? That's exactly the danger pointed out in this thread about battery fires. They didn't think about what type of BMS you have in your 20Ah battery with a single charge MOSFET rated at 5A max, nor the wires connecting the charge port to the BMS. They just look at what the cells can do and spout their theories to unsuspecting victims, who end up burning their houses down, then blame the Chinese.
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I try to charge to 80% - 90% on most occasions and charge to 100% to balance cells from time to time while avoiding draining battery flat.
I simply don't trust them. Do you?
That's not good because the balancing current is so small. It's designed to work on the "little and often" principle. To ensure that the cells get balanced, you need to leave it on maximum charge for longer, but that damages the cells more than if you had simply charged to 100% every time and switched off when the light went green.
Yes I do. Many forum members have had exception life from their Bosch batteries. Also, there is no reason why they'd want their batteries to wear out quicker than they needed to. I don't support the theory that they're trying to make money from selling replacement batteries because the Amazon ebike sellers never get the chance to sell a replacement. Any profit made on Chinese bike batteries would be made by the dealer, not the factory. Also, I know how most BMSs work. When I make my own batteries, as I am right now, I put in a standard BMS and charge to 100% just like all the other manufacturers recommend.
There are many more considerations than cell life. There's overall cost to consider, changes in technology, changes in cell quality, overall capacity, damage from over discharging. If people want to get long life from their batteries, charge them to 34v, then stick them in a cupboard for 10 years, then come on the forum and boast how great you are at looking after your battery. I have some batteries that are that old and still working well. Aren't I clever. I hereby promote myself to Battery Life Guru for that. Yippee!
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If there was a charging regime that could considerably extend the life of a battery it would be no surprise if manufactures such as Bosch, Shimano, Yamaha, Pansonic, Bafang etc. would not want to encourage it, they make money selling batteries after all.
In addition whilst the manufacturers could give users the choice of how to charge their batteries, they do not, no surprises there either.
If you switch off when the light goes green there is no guarantee that balancing is complete. Significant current is still flowing even when the light is green...it is a lottery, you don't know what is going on inside just because a light goes green.
@saneagle, you make some valid points, but only because the industry is such a mess and the consumer is at the bottom of any consideration. This means for the average person on the street there is not much they can do to prolong battery life other than not to let their pack discharge too deep too regularly and not to leave their pack in a hot environment.
The science behind what causes cell degradation is quite well known and understood. But there is little interest in the battery pack industry to implement measures that will extend the life of their packs. It's shooting themselves in the foot, and what sells is biggest advertised capacity in the lightest package, not our pack will last for 5 to 10 years rather than 3 to 5 years.
A BMS will work fine if a pack is not charged to 100%. The only thing it will not do is balance. However, I would not be surprised if a lot of packs never get a balance ever, since the output of their chargers does not go high enough to initiate balancing. A charger needs to output at least 4.18 V/cell for the average BMS to start balancing. QC on chargers seems very poor these days and I've seen anything from 41.5 V to over 43 V for a 36 V charger.
@saneagle, you make some valid points, but only because the industry is such a mess and the consumer is at the bottom of any consideration. This means for the average person on the street there is not much they can do to prolong battery life other than not to let their pack discharge too deep too regularly and not to leave their pack in a hot environment.
The science behind what causes cell degradation is quite well known and understood. But there is little interest in the battery pack industry to implement measures that will extend the life of their packs. It's shooting themselves in the foot, and what sells is biggest advertised capacity in the lightest package, not our pack will last for 5 to 10 years rather than 3 to 5 years.
A BMS will work fine if a pack is not charged to 100%. The only thing it will not do is balance. However, I would not be surprised if a lot of packs never get a balance ever, since the output of their chargers does not go high enough to initiate balancing. A charger needs to output at least 4.18 V/cell for the average BMS to start balancing. QC on chargers seems very poor these days and I've seen anything from 41.5 V to over 43 V for a 36 V charger.
I measured my charger's ouput last night, and I got a reading which skipped continuously between 42.5 and 43V - I was using probes, which may have been the cause of the variation. Once my battery stops charging and (hopefully) balancing, I'll measure again, this time attaching a crocodile clip on the exterior of the barrel connector.
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If people really wanted long-life batteries, they could get LiFePO4 ones, like I have in my house. They're guaranteed for ten years using them every day. the price is roughly the same as normal lithiun-ion ones for the same number of watt-hours, but hardly anybody wants them. Kudos bikes used to have them, but I can't remember anybody recommending or choosing a Kudos bike because it had long battery life.
You need special eqipment when measuring things like that accurately, so don't do anything on the basis of a normal multi-meter. Chargers don't have to give out smooth voltage, so you could be measuring the peak of the ripple. You'd have to check it with an oscilloscope to see what's really going on. Look here on page 14 - nearly 1/2volt ripple: