Samsung Ebike Battery - faster or/and more portable charger?

[=BicycleRider=]

Hi,

I have an ebike with a Samsung MTI 36v 10.4amp hour battery that looks like this.

But the charger is a bit chunkier and has a larger ac input plug.
Not from this seller though.

I was wondering if anyone has one.
It currently includes a 42v 2.0 amp charger.
Can I get a faster charger that is more portable, without voiding the warranty or over burdening the battery?
Ie. Maybe 3 hour instead of 5~?
It would need to work with Australian voltage 230v.

 

[Hillhater]

Sure, you could find a 3, 4, 5, etc Amp ,36volt charger (which will charge to 42 volts) like this..
http://www.ebay.com.au/itm/like/281779037406

 

[=BicycleRider=]

Thanks, so it's definitely a lifepo4 battery?
Do you think charging at 4.5amps instead of 2amps (every now and then) would shorten how long the battery lasts by a lot?

 

[dustNbone]

Even 6 amps is just over .5C on that pack, should be fine. As long as the voltage matches, you should be good to go. I don't think that's a LiFePo4 pack but it's possible. Either way, as long as you're using the correct charging voltage, you'll be fine.

 

[Hillhater]

Thanks, so it's definitely a lifepo4 battery?
Do you think charging at 4.5amps instead of 2amps (every now and then) would shorten how long the battery lasts by a lot?

No, its a Lion battery
And no, charging at 4 or even 6 amps , every now and then, wont shorten the life noticeably.

 

[=BicycleRider=]

Thanks.

How many cycles would you expect a lion battery of that size and capacity to last?

 

[Hillhater]

Life would depend on the type of use..
What discharge rate...it varies a lot on a bike.
How much discharge each cycle ? 30%, 50%, 80%, etc ??
Ambient temperature ?
...but with "normal use". you ought to expect 500-1000 charge cycles ! (SWAG)

 

[cell_man]

The cells should be fine at 5a charge rate, but you need to check the charge plug. The dc2.1 connector, that is common on many of these sort of cases are only 3a rated. Also, the small bms in these battery cases often are only intended for around 3a charge rate.
To cut a long story short, you'd almost certainly be ok at 3a charge rate, but much more and there is a chance you may run into a problem.

 

[=BicycleRider=]

Thanks, it is the type e plug.

Can't see any rating written on the socket though.
Should I check the fuse?

How close could you expect to get to the mathematical 3.46 hour charging time for 3amps into 36v 10.4 amp hour battery after losses etc?

 

[cell_man]

Type E is a DC2.1 connector as far as i can tell. They are normally 3A rated. I'd limit the charge to around that, if much more, you may run into problems with the connector, or possibly the BMS. You might get away with it, but not worth taking the risk IMPO.

I'm guessing that if you really fully discharged the 10.4Ah pack and charged it with a 3A charger, I'd expect it to take about 4-4.5hrs, but most of the time you will not be starting with a fully discharged battery (better you don't). The final CV stage of the charge process where the current tapers down is quite slow.

 

[=BicycleRider=]

Thanks, yeah I won't risk it since it's a new bike/battery.

Do you think there is any chance that 3a could damage any part of the battery/bms?

 

[=BicycleRider=]

Will I require one with that automatically shuts off when the battery is full? I assume so.

 

[danielrlee]

Will I require one with that automatically shuts off when the battery is full? I assume so.

No. Balancing occurs at the end of a charge and can sometimes take quite a while. If the charger were to shut off, the BMS wouldn't get a chance to do so.

 

[=BicycleRider=]

Ok thanks, but does that mean I could use any power supply with the right voltage? that can produce the number of amps required?

 

[danielrlee]

Ok thanks, but does that mean I could use any power supply with the right voltage? that can produce the number of amps required?

No, as well as being the correct voltage, the power supply needs to be a constant current (CC) one. These provide current limiting at a level that will not harm your battery.

 

[=BicycleRider=]

Ok thanks, also most are rated at 220v so will probably break after a while on the 230+ v here maybe breaking the battery too.

 

[dustNbone]

Most stuff that says 220V is fine for 208 to 240 at the very least, and a regulated supply will maintain a constant(ish) output voltage through a range on input voltage. Won't hurt supply or batteries.

 

[=BicycleRider=]

Would a 45v charger be ok if it says meant for 36v batteries.

 

[danielrlee]

Would a 45v charger be ok if it says meant for 36v batteries.

Definitely not. A 36v Li-ion battery requires a charger that outputs 42v. The charger you mention is probably meant for charging lead a acid battery that has a higher termination voltage than Li-ion.
If you post a link to a specific charger, we can confirm if it is suitable.

 

[=BicycleRider=]

Would something like this be suitable?
http://www.ebay.com.au/itm/42V-2A-Charger-For-36V-Li-ion-Lithium-Battery-Two-Wheel-Self-Balanced-Vehicle-/322293550476?hash=item4b0a314d8c:g:GtUAAOSwYIxYAKAu

It's for a secondary charger to top up for the return trip.

What could the drawbacks be to a cheaper one vs one for around $35+? For topup charging.