Charging dolphin pack with a 5amp charger

Hi All,
I have just got into the obsession of Ebikes after 20 years of serious cycling and racing on the road.
I love being able to do my 40km commute to work in an hour, and more recently doing 150km and 200km rides, which were getting harder and harder to do on a regular road bike.
Problem is, I've entered the game on a 1000w hub drive kit with 48v 15ah battery.
Range is not great, so I decided to pause for a coffee and charge the bike to go further on long rides.
The 2 amp charger which came with the kit only gives me 30 minutes of cycling for 1 hour of charging.

I purchased the charger below on a whim, which would give me 5amp charging, which I plan to use on rare occasions, and for only an hour at a time, so that I could do some long rides.

https://www.ebay.co.uk/itm/Electric-Bike-48V-5A-Lithium-Li-ion-Battery-Charger-Lipo-Lifepo4-Scooter-E-bike/282694073043?ssPageName=STRK%3AMEBIDX%3AIT&var=581921086807&_trksid=p2057872.m2749.l2649

Could any of you give me an informed opinion on whether this would be safe to use, before I take the dive and try it out? One big question to add, is how might I be sure of the chargers polarity? It has the correct plug for dolphin, but if they messed up the polarity I might turn the battery into a bomb?

Any advice greatly appreciated!

Cheers,
Biggsy
Pyrenees, France

You will need to say which cells are being used to charge at 5a also a faster/higher charge rate will or may reduce cycle life, it all depends on actual cells used.

Thanks a lot for the response hemo.

From the website selling the kit :

All batteries are built using high quality Samsung / LG battery cells and also a built in High Quality Battery Management System (BMS). This ensures that all your battery cells are evenly charged and it won't overcharge the battery ..

I would only plan to charge the battery by 30 percent, never to full, and only once or twice a month.

Would either the bms, or the internal fuse protect the battery if this charger isn't compatible?

Thanks a lot,

The plug/socket on the battery may only be rated for 3 amps, so might overheat and melt.

to add: I have had a em3ev Dolphin pack and this is what Paul has said.

Jon NCal said:

The plug/socket on the battery may only be rated for 3 amps, so might overheat and melt.

Click to expand...

I highly doubt it.

A picture or a link would help of course.

Almost every cell formulation on the market can accept a 0.3C rate charge.. ( 15AH / 5A = 0.3C ).
It would be useful to know what cell we're talking about.

Plug might melt? um, we haven't seen the plug either. We don't even know who made the battery.

More information would be helpful.

Well, it's a LUNA Dolphin pack?. So I'd say a standard XLR plug that in some cases can handle 10A (the high-quality ones). The cheapo plugs can easily handle 5A.

So all you need to do now is figure out if the Charge + is on pin 1 or 3.

From my experience, most chargers and battery packs that use XLR have the C+ on pin 1.
I would still check it with a multimeter though.

Or maybe it is written on the Charger, check it first.

You need a multimeter their free or $5 even $7 this will tell you polarity. Which you should always check with new items they're all made in China at Red doesn't mean anything white doesn't mean anything and black doesn't mean anything check it. Most quality bms's can handle 5 amp but in your case it seems like you need an adapter and I have to take the battery off his rack. More info on battery.

Thanks a lot for your feedback guys.
I've opened the battery to take a look and attached some pictures.
The plug looks pretty standard, and the power cables between it and the cells look pretty beefy. It seems that this type of circular plug must be neutral exterior, positive interior, otherwise it would have a dangerous risk of electric shock.
The cells do say made in china, so perhaps I got done, but the dealer seems to have gone out of business.
I think there are 54 cells.

Hard to know the charge rate of that bms.

Your picture says you've got 2.4AH cells in there. If it really was a 15AH battery, you would need six of them in each parallel group to get close to 15AH. Then 13 groups in series to get 48V, for 13S-6P is 78 cells. I think you have 52 cells for a 13A-4P and it's a 10AH battery with four cells in each group. So the question is can you safely charge these at 1.25A per cell?

Me, I'm charging some of my batteries at slightly over 1A per cell. but they are supposedly Panasonic 26F cells rated for 1.3A.



More number chugging. One hour of charging at 2A is 2AH, about 100 Watt-hours. That gives you 30 minutes of riding. If that's at 24 mph, then that's 12 miles in 30 minutes or 8 Watt-hour per mile.You're doing a lot of pedaling!

docw009 said:

Me, I'm charging some of my batteries at slightly over 1A per cell. but they are supposedly Panasonic 26F cells rated for 1.3A.

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Thanks a lot Docw009, Its some really helpful info.
I don't feel much closer to the answer though.
Do you think I should try it out, or it's too risky?
I only plan to use it occasionally for short periods, though I can't work out the odds of it being safe.