mrbikeyboy

hi. I have a master ebike that has 3 batteries lined up in a row in a plastic case. They are 12V 12AH and are Sealed Lead Acid. I need a charger for it. The case has a little thing that looks like a video RCA plug on a VCR. This is where the charger goes. Has anyone ever seen a charger like this? I am including pictures. Does anyone know what voltage and amps a setup like this is putting out?
The current batteries are Haijiu 6-DFM-12A. I also need to replace the batteries. What is the best and least expensive internet battery site. I need 3 batteries and the charger.

Abneycat

I haven't seen a connector like that before, personally. That setup would put out 36v@12ah. Since the wiring setup seems fairly standard and the cables are obviously capable of handling the current (at least one would presume so, as they're whats in the box), it would be pretty simple to just use the box, load in some new batteries, drill another hole in the box or just remove that plug, and use any charger you wanted, I would think. You can buy 12v batteries in a lot of stores locally. Find Deep discharge ones, don't use batteries made for cars.

dwainedibbly

The Wilderness Energy kits use that type of connector for the charger. See https://www.werelectrified.com. I think they sell 36v 2amp chargers for $75 or so, but I'm double check the polarity.

SLA batteries: https://www.batterywholesale.com/. I just bought some 8Ah 12v SLAs from them. They were the cheapest place I found.

mrbikeyboy

hi Abneycat! THanks for all the help. You mentioned deep cycle. I found this battery: https://www.tempestbatteries.com/html/td12-12.html
It is the TEMPEST TD12-12 AGM DEEP CYCLE BATTERY.
I do not know what "AGM" stands for....do you? Do you think this would work ? or what do you recommend? I was hoping to spend around $30. per battery or less if I can as my funds are limited.
Also, I found this charger: https://www.electrictransport.net/sho...asp?itemid=142 Do you think it would work? I see there are a ton of different 36v chargers. I just need one to charge and time does not matter. As long as it can charge overnight, I am happy.

mrbikeyboy

Hi dwaindibbley! Thanks for the info. You mentioned you found the 8ah 12v at a very reasonable price. My bike has the 12ah 12v. What would be the difference in performance in using the 8ah over the 12ah. Remember, I am new to this and I know NOTHING about amps or electricity. THANKS MUCHLY!

rlgreer388

You may want to take a look at TNCScooters.com. They have cheap batteries, cheap chargers, and other small electrical parts. I bought 3 12v 12ah batteries and a charger from them about a month ago. So far so good.

Their prices are so low their stuff can't be very high quality, but they shipped same day both times I ordered from them and everything seems ok so far.

Abneycat

Those batteries are "Absorbent glass mat" batteries, not the same design as SLA which stands for Sealed Lead-Acid. They aren't permanently sealed and have gas diffusers on the top to let out materials during stressful overuse or overcharge. I know that AGM batteries are used in some electric vehicles, and that they have good specs when compared to SLA, but i'm not entirely sure about the use of them on an electric bicycle. You should probably do some research on these if that chemistry interests you, because they look okay to me but i'm not 100% on that.

dwainedibbly seems to know the connector, and a good source = )
You would likely want to stay using 12ah batteries. This is how it works: Volts x amps = watt-hours. This is the easiest way to figure out your overall battery capacity because you can compare this to any voltage you want.

Your battery setup 36v x 12ah = 432wh of energy.
36 x 8 = 288.

So moving to a 36v/8ah pack would drop your net energy capacity down considerably, as you can see.
https://www.batterywholesale.com/batt...tml?prodID=376
Those ones on dwainedibbly's site would be the equivalent of what you have. Remember that they're relatively heavy so shipping them will increase the cost quite a bit if you don't buy at least nationally instead of internationally. These guys are in Texas.

If you go into an LBS that deals with electric systems and carries Wilderness Electric, you could probably figure out pretty easily if those chargers will work out for you or not too.

dwainedibbly

^what he said....

I'm in FL. Shipping from TX was approx $15.50 for 3. I priced the 12Ah batteries from them, too, and shipping was in the $20-25 range.

I had 12v 12Ah batteries before this set but wasn't using much of the capacity on my commute, so I went to the smaller (and lighter!) 8 Ah batteries to save wear & tear on my rear rack, real wheel, etc.

Another nice thing about the 8Ah batteries is that 4 of them will fit in the space of 3 of the 12 Ah ones, so if I wanted to go to a 48v setup I could do it, assuming my motor controller could handle the load, of course.

Abneycat

This is another possibility you could look at, as long as the "Master ebike" controller was capable of handling the additional load. It wouldn't carry quite as much capacity at 48/8, but it would be close and you'd see a considerable speed/torque increase. I've always been a fan of going with 48v and simply matching watt-hours up to a 36v pack as opposed to just increasing the capacity on a 36v. Same range at the same speed, but more speed if you want or need it. That might be a little more technical than you're used to though, and finding information on whats inside this thing could be quite hard.

One thing I forgot to mention which is important! That housing unit looks like a tight fit to those batteries. Whatever you choose to go with, if you're planning on keeping that unit then measure up the space you have to work with and make sure your new batteries are going to fit in there properly, it wouldn't be too fun to order in your power and find out its 6mm too wide, naturally.