I am stuck on what battery to get as my second battery. I have studied all of the Li-ion packs out there, and have a good feel for the differences Li-ion 18650 cell brand, quality, and the options for voltage and amperage. WHEN I decided to look into normal deep cycle lead acid batteries, I realized I could create a 48v 100 Amp battery for about $400 (with 4x 12v 100A batteries in series). This would power my bike for 100 or more miles, EASILY. It would not take up too much space, and could easily be placed in a basket. Why do folks not use this option instead of paying $600 for a 20a 48v good quality Li-ion Samsung 18650 cell battery pack which has 1/5 of the power (amperage) of my proposed set-up? I could use my car battery charger to charge it so charging is not an issue. What, if anything, am I missing?
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Check out the size and weight of each 12V 100 Ah deep cycle battery.
For reference, a Group 24 battery is usually 75 Ah, the size of a car battery, 45 pounds, and you shouldn’t discharge it below 50%, meaning it’s a usable 38 Ah.
And a Group 24 at Wal Mart is $75. So $300 buys you a 180 pound, 48V lead acid battery with 38Ah of usable capacity. And unless you buy a 48V lead acid charger, you have to charge each battery individually.
For reference, a Group 24 battery is usually 75 Ah, the size of a car battery, 45 pounds, and you shouldn’t discharge it below 50%, meaning it’s a usable 38 Ah.
And a Group 24 at Wal Mart is $75. So $300 buys you a 180 pound, 48V lead acid battery with 38Ah of usable capacity. And unless you buy a 48V lead acid charger, you have to charge each battery individually.
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Explorer-1
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You might also read about the Lead Acid Chemistry and how far you can safely discharge them, you may find out something important about that 100Ah rating. Early bikes did use Lead Acid cells of different varieties, and if you have any experience with these cells you would be more than ready to move to Li-Ion chemistry.
Companies like Samsung, and LG make many different models of the 18650 cells, all are not created equal.
If you want to try something different you can look at Li-Pol cells or some of the large format automotive grade Li cells. However you can save yourself a lot of headhache and hassle and just get a battery that is build with Sanyo/Panasonic GA cells and as long as the rest of the battery is solid and the design is solid you are good. If you need a very special pack where these would not be suitable, then choose wisely.
Companies like Samsung, and LG make many different models of the 18650 cells, all are not created equal.
If you want to try something different you can look at Li-Pol cells or some of the large format automotive grade Li cells. However you can save yourself a lot of headhache and hassle and just get a battery that is build with Sanyo/Panasonic GA cells and as long as the rest of the battery is solid and the design is solid you are good. If you need a very special pack where these would not be suitable, then choose wisely.
Thanks for the input. The one thing I overlooked is the size and weight. In my mind I envisioned a typical 3" x 6" x 4" UPS size battery, weighing perhaps 10 pounds each. Boy was that a major misjudgement on my part! I was thinking deep cycle gel cells, but I am punting this idea!
Absolutely! I just need to decide if I want to go 52v, and if i am willing to pay extra for good quality 18650 cells over the cheap Chinese ones! I am even contemplating building my own. Right now it looks like the 52v Shark battery pack is in the running, but at $600++ (shipping, charger, mount.etc) for 52v 17.5A seems stiff. The Chinese make a battery, mount and charger, 52c, 20A 13S for $220 plus $20 shipping. I could buy 3 for the price of 1 shark! Then I see this one (52v 50A, with everything, for $649. I just don't know what to think...
https://www.electrifybike.com/store/p132/52v_50-AMP_Continuous_Jumbo-Shark_E-bike_Battery.html#/
I found this chart, which will be helpful!
https://www.electrifybike.com/store/p132/52v_50-AMP_Continuous_Jumbo-Shark_E-bike_Battery.html#/
I found this chart, which will be helpful!
AHicks
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Whatever you do, I would strongly advise against building your own pack - unless you can buy cells that are guaranteed to match (good luck!). Unless they match nearly exactly, the pack will not balance correctly and you'll have an expensive headache. It's not worth it unless you have money to burn.....
Thank you! I am just now learning the ins and outs of battery pack construction. I got Micah Toll's book on pack construction, but frankly, the parts costs is higher than I thought, and the repetitive tasks of construction do not appeal to me...
Yes I did mean batteries with cheap Chinese cells, and should have said "Battery packs with no name cheap Chinese cells". My understanding is that the only decent 18650 cells are offerings from Sony, Samsung, or Panasonic. Another newer brand which I will review further is Molicel.
tomjasz
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GA and a number of cells are made in China. Brand name battery makers have a presence in China. There are some excellent Chinese-made batteries, just not commonly found or sold to end-users.
tomjasz
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I agree for the most part. Jumping into building decent packs gets expensive when setting up with the correct tools. Thats said I've never gotten a batch of new brand name cells that weren't compatible. All have been in the same voltage range. by a tenth or two.
Because I have a pacemaker I have to retire my spot welder and will use Vruzend kits from here.
There are some serious pitfalls and shorting out a 56.4V pack can lead to a disaster. Least of which is Kentucky fried fingers.
NEVER WEAR RINGS!!!
Explorer-1
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I bought this battery a couple weeks ago when he announced them. It uses pretty crappy version LG cells but since it's a large pack they are OK for a non-high performance bike. Just bought it to play with, might use it on a bike, might not.
Kyogiro
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Are you going to replace the battery or use the new one as an additional one ?
Connectivity is not the same, so I guess either you're gonna use an adapter (I only saw one at Bolton ebikes, but it's sold out) or replace the old Rad plug with the new one (XT90 or Anderson I believe).
Connectivity is not the same, so I guess either you're gonna use an adapter (I only saw one at Bolton ebikes, but it's sold out) or replace the old Rad plug with the new one (XT90 or Anderson I believe).
tomjasz
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WOW!!! Still using 29E cells.
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