Charging dolphin pack with a 5amp charger

Batteries, Chargers, and Battery Management Systems.
Post Reply
Biggsy   10 mW

10 mW
Posts: 30
Joined: Oct 05 2018 2:42pm

Charging dolphin pack with a 5amp charger

Post by Biggsy » Nov 07 2018 3:54am

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-Bik ... 2749.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

hemo   100 W

100 W
Posts: 196
Joined: Mar 30 2016 5:13pm
Location: England, GB ( UK).

Re: Charging dolphin pack with a 5amp charger

Post by hemo » Nov 07 2018 10:56am

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.

Biggsy   10 mW

10 mW
Posts: 30
Joined: Oct 05 2018 2:42pm

Re: Charging dolphin pack with a 5amp charger

Post by Biggsy » Nov 07 2018 11:28am

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,

Jon NCal   1 kW

1 kW
Posts: 369
Joined: Jun 15 2015 3:59pm
Location: Mendocino, California

Re: Charging dolphin pack with a 5amp charger

Post by Jon NCal » Nov 07 2018 12:40pm

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.
Last edited by Jon NCal on Nov 10 2018 12:00pm, edited 1 time in total.

User avatar
eee291   100 kW

100 kW
Posts: 1078
Joined: Nov 05 2015 4:35pm
Location: Austria, Burgenland

Re: Charging dolphin pack with a 5amp charger

Post by eee291 » Nov 07 2018 1:02pm

Jon NCal wrote:
Nov 07 2018 12:40pm
The plug/socket on the battery may only be rated for 3 amps, so might overheat and melt.
I highly doubt it.

A picture or a link would help of course.

User avatar
neptronix   100 GW

100 GW
Posts: 14196
Joined: Jun 15 2010 5:56pm
Location: California refugee living in Utah, USA
Contact:

Re: Charging dolphin pack with a 5amp charger

Post by neptronix » Nov 07 2018 1:08pm

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.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: 20" eZee on a Cannondale Semi Recumbent.
Whipper-snapper: ? on a lightweight BikeE Semi Recumbent

User avatar
eee291   100 kW

100 kW
Posts: 1078
Joined: Nov 05 2015 4:35pm
Location: Austria, Burgenland

Re: Charging dolphin pack with a 5amp charger

Post by eee291 » Nov 07 2018 1:16pm

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.
Last edited by eee291 on Nov 10 2018 4:19am, edited 1 time in total.

999zip999   100 GW

100 GW
Posts: 9326
Joined: Jan 10 2010 1:40pm
Location: Dana Point So. Cal

Re: Charging dolphin pack with a 5amp charger

Post by 999zip999 » Nov 07 2018 1:57pm

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.

Biggsy   10 mW

10 mW
Posts: 30
Joined: Oct 05 2018 2:42pm

Re: Charging dolphin pack with a 5amp charger

Post by Biggsy » Nov 09 2018 7:49am

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.
Attachments
IMG_20181109_122754.jpg
IMG_20181109_122628.jpg
IMG_20181109_122615.jpg
IMG_20181109_121846.jpg
IMG_20181109_121826.jpg

999zip999   100 GW

100 GW
Posts: 9326
Joined: Jan 10 2010 1:40pm
Location: Dana Point So. Cal

Re: Charging dolphin pack with a 5amp charger

Post by 999zip999 » Nov 09 2018 1:51pm

Hard to know the charge rate of that bms.

docw009   100 kW

100 kW
Posts: 1279
Joined: Aug 02 2015 7:43am
Location: Chicago area suburbs.

Re: Charging dolphin pack with a 5amp charger

Post by docw009 » Nov 09 2018 6:33pm

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.
IMG_20181109_122754-3.jpg
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!

Biggsy   10 mW

10 mW
Posts: 30
Joined: Oct 05 2018 2:42pm

Re: Charging dolphin pack with a 5amp charger

Post by Biggsy » Nov 11 2018 1:32am

docw009 wrote:
Nov 09 2018 6:33pm
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.
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.

Post Reply