A guy as brought his electric folding bike into my workshop, the lithium battery is 24v but I checked his charger with my meter and reading as says on the charger 42v
The guy says he has been using the charger which came with the bike for 2 years
Is it best to get the correct 24v output charger
Safety wise yes, he is soley relying on the BMS to stop the cells over charging, possibly shorting and catching fire. The guy isn't worried too much about his safety or others who may live with him.
Most incidents with battery fires is down to mis use and charging is the biggest risk.
You are correct in your reasoning to qestion his technique.
Thanks and that is a great reply, It will be passed on to my client.
I did point out to him by email telling to be careful the risk of fire when he sent an email attachment photo of his battery all striped down.
thanks again
I'm quite surprised that the 24v bike was a supplied with a 42v charger and is a very risky thing to do.
We hear of a few battery fires and a lot appear to occur during the charge stage and likely over charging or extended periods left on charge.
His BMS only has to suffer a fault on the charge side and the battery possibly could go as high as 6v for a 4.2v cell will be a dangerous occurrence should it happen.
Lithium cells have 4.2v max charge with some BMS having a 4.25v/4.3 v release voltage should a fault occur any higher then a cell is well beyond it's capability.
A guy as brought his electric folding bike into my workshop, the lithium battery is 24v but I checked his charger with my meter and reading as says on the charger 42v
The guy says he has been using the charger which came with the bike for 2 years
Is it best to get the correct 24v output charger
I am going to be discordant ... If you measure the Charger voltage off load , and without any load attached, you can basically read anything .. so 42V is not unlikely... You need to have some type of load on it ... Even a 200 ohm resistor would suit ..or a domestic incandescent light bulb. or Two car bulbs in series.. basically something that draws a current. Now a 24V lithium battery pack is more like 29v fully charged , and a charger will be outputting 36v into that load ,to give a 3 to 4 Amp charging current. .
Finally depending on the age of the bike, it might bea pre Lithium battery pack .. Ni Mh was popular, which will take a lot more abuse.
Hi I have a question for you, new lithium batteries on the shelf waiting to be fitted and perhaps 80% charged what sort life are the batteries are good
for and are they still as good if they are in stock for say over 12 months
thank you
Ron
Hi I have a question for you, new lithium batteries on the shelf waiting to be fitted and perhaps 80% charged what sort life are the batteries are good
for and are they still as good if they are in stock for say over 12 months
thank you
Ron
There is a small decline in capacity over time, but much smaller than the decline due to use. 12 months sitting on a shelf in a medium state of charge is unlikely to make a noticeable difference. Sitting flat would be a different story.
There always a problem that we never know how long the battery suppliers
have had the batteries in stock, we can easily end up with a battery 18 months old before its fitted onto a bike
