Want to buy Lithium Batteries...Where? - DIY Solar Power Forum

I am looking for a reliable vendor in the usa that sells lithium batteries, I was looking for the Trojan Trillium 12.8 but am open to options.If you have any advice on a seller of these batteries ¨new¨ please post it here....please
Thank you

BigBatteries.com is in the United States just outside of Los Angles. They are only 200 miles from me and I will pick mine up in person so I don't have to pay for shipping. This is one of the batteries I'm looking at. Note, check Wells website for a 10% discount with BigBatteries.

Bigbattery does not have anymore of the 48v wall mount systems, the website says out of stock

get on their mailing list. they are not out of stock very long. but their popular batteries sell out fast. You only have a few days to buy a battery from them once you get the notification that they are back in stock.

However, since you mentioned it, I don't recall see wall-mounted batteries either, like Tesla. As for me, I can't have a battery on the wall, so I wasn't looking for one.

The other reason I'm looking at big batteries is that I live close to them and can pick the battery up directly from them and save a few hundred dollars in the shipping cost. - I think these shipping costs are out rages that these companies charge.

Are you looking for Manufacturered Pre-Assembled Battery Packs ? You mention the Trojan Offerings, so.... Commerccial Batteries will certainly cost more but you get warranties & an assurance that the batteries are well tested with quality components. DIY can be as much as 50% less expensive (in some cases even more). You can DIY with High Quality Grade-A Matched cells and still save some money but without a manufacturer warranty.

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Hello, yes I am looking for something that is ready to go I do not know much about assembling and testing battery packs
I am handy though.

First time caller, long time listener.

Okay, so I have a TXT PDS with 23" tires on the stock 350a shunt controller,.

The lead acid batteries crapped out, so I went with a 36v Kepworth litnium LifePo4 battery. It seemed to work great at the beginning. The first thing that went wrong, was when I was climbing a steep hill. It shut down due to overcurrent. Okay, no problem, I can deal with that. A 30 second rest is all it needs.

Then, we took it to a campground for Memorial Day weekend. It seemed okay, we were slow cruising, then I noticed it slowing down, then, it just stopped. The monitor showed it had 89% battery life. Waited 2 minutes, it took off again. But, all weekend long, it continued to 'thermal shutdown' on us.

I contacted Kepworth, they said my golf cart is too powerful. Huh??? It’s a stock 36v motor with a 350w shunt controller. The tires are oversized, but that's the only mod.

They wanted me to add a 2nd 36v pack, but there's no way, these Kepworths are huge.

I ended up sending them screenshots of the 3rd page on the monitor. This page shows the health of each individual cell. After it has rested, the cells are all very close, but when the cart dies, one cell is much lower.

So now, they want to send me an equalizer plate to put on, but they don't think it will solve the issue. It should, if the plate does its job, but this is not my area of expertise.

I took the cart to a local repair place, they think it’s the battery.

At this point, I'm ready to send the battery back and buy two 36v enjoybot batteries and parallel them. It looks like they will fit.

So I have questions:

1) is this the right upgrade?

2) How do I hook up the charger? Do I need to use a + buss bar and a - buss for both batteries and charger to marry, or can I just hook the charger to 1 battery (I'm guessing the answer is no)?

3) Will this be too much for the controller and/or motor?

4) Will this upgrade benefit me when climbing hills?

5) I'm assuming I'll need to charge both batteries seperately to equalize them prior to hooking them together?

I think that's about it… for now.

Do you have one 36v battery or 3 x 12v batteries? It sounds like you have one 36v battery but the manufacturer wants to send you a balance board to you to install on the battery. Thats not a simple task, not difficult, but definitely not plug and play.

It sounds like you have one bad cell, a balance board will just hide it, not fix it. Send it back and get a better battery with real customer support that’s designed for cart use. Look at Eco Battery or Epoch.

A quality battery should never shut down on you unless you’ve let it get too low.

Yeah, it's a single 36v battery.
Lucky me, I get a bad one. They seem to think my cart damaged the battery. I'm not sure how that's possible.

Yeah, it's a single 36v battery.
Lucky me, I get a bad one. They seem to think my cart damaged the battery. I'm not sure how that's possible.

No way your cart damaged their battery. It's impossible. Their battery has a BMS board in it that is there to prevent damage from external devices. If your cart presented a load that the battery couldn't run then it should have shut down. More likely, they're using cheap or second hand cells that aren't up to the task, with the BMS setting set too high and allowing too much current to flow through those inadequate cells. That's how these cheaper batteries are claiming high currents. They are trying to get out of a warranty claim.

No way your cart damaged their battery. It's impossible. Their battery has a BMS board in it that is there to prevent damage from external devices. If your cart presented a load that the battery couldn't run then it should have shut down. More likely, they're using cheap or second hand cells that aren't up to the task, with the BMS setting set too high and allowing too much current to flow through those inadequate cells. That's how these cheaper batteries are claiming high currents. They are trying to get out of a warranty claim.

I agree with this. If the battery is properly designed the BMS will shut down before damage can occur. Sounds like you got a battery with a bad cell no way around it. You get what you pay for, there’s a reason these amazon batteries are a third of the price of reputable brands. They can claim whatever they want about how long their warranty is, most of those sellers will try to blame you, give you the runaround, or just ghost you. They could care less if that account gets banned, they probably already have 10 other accounts selling the exact same thing under a different name. Not that Amazon actually cares that people sell garbage products on their platform as long as they’re making their sellers fees. Buyer beware is the name of the game with these budget lithium batteries.

No way your cart damaged their battery. It's impossible. Their battery has a BMS board in it that is there to prevent damage from external devices. If your cart presented a load that the battery couldn't run then it should have shut down. More likely, they're using cheap or second hand cells that aren't up to the task, with the BMS setting set too high and allowing too much current to flow through those inadequate cells. That's how these cheaper batteries are claiming high currents. They are trying to get out of a warranty claim.

They have been very helpful and have told me they will refund my money on a return. But they want to test it first and now they're telling me their engineer is on vacation for the next two weeks. Ugh.

I agree with this. If the battery is properly designed the BMS will shut down before damage can occur. Sounds like you got a battery with a bad cell no way around it. You get what you pay for, there’s a reason these amazon batteries are a third of the price of reputable brands. They can claim whatever they want about how long their warranty is, most of those sellers will try to blame you, give you the runaround, or just ghost you. They could care less if that account gets banned, they probably already have 10 other accounts selling the exact same thing under a different name. Not that Amazon actually cares that people sell garbage products on their platform as long as they’re making their sellers fees. Buyer beware is the name of the game with these budget lithium batteries.

It got really good reviews, I thought this was going to be a good option. Hopefully it's just a situation where I was unlucky and got one of the few with a bad cell.
Man, it doesn’t take much to make a battery fail.

It got really good reviews, I thought this was going to be a good option. Hopefully it's just a situation where I was unlucky and got one of the few with a bad cell.
Man, it doesn’t take much to make a battery fail.

A couple of points, a lot of those reviews may be fake, and it does take a lot to make a well designed battery fail.

A well designed battery will have cells that are up to the task, in this case, being able to supply at least 100A to 150A continuously with peaks up to 300A for 10 to 30 seconds. They may have 3 or 5 second peaks of over 500A. Then a BMS will be installed to protect those cells if the load tries to draw more than the current the cells can safely supply. Note, that if the cells are operating within their design limits, they shouldn't fail and it's the BMS's task to ensure that occurs.

Note, that I'm talking Amps above, not Ah. They are totally different things. Ah's is how much energy the battery stores (range), Amps are how fast it can deliver that energy (required for acceleration, going up hills etc.).

Okay, so if I move on from this battery and go with 2 100ah batteries, will that help with the stress caused by the 23" tires? I didn’t put those tires on, they were onit when I got it last year. The lead acid batteries did okay, the cart was just slow on inclines.

Look at @Pat911’s post above. You need to look at the discharge amp limit, not amp hours. The discharge current is how many amps can flow at once, the amp hour rating is how many amps are stored inside the battery total. The fire department can have a full tanker of water, but it won’t help if they’re trying to spray it through a drinking straw.

Okay, so if I move on from this battery and go with 2 100ah batteries, will that help with the stress caused by the 23" tires? I didn’t put those tires on, they were onit when I got it last year. The lead acid batteries did okay, the cart was just slow on inclines.

No; not really. Think of your battery as your fuel tank. More AH is like more gallons so with more AH you get more range not more torque. One good battery should handle your needs unless you need more range. If you need more torque you will need to upgrade your motor. Before you go buying a motor designed for more torque you will need to make sure your controller will provide the current (amps) to feed it. Think of your stock motor as a stock motor and your controller as a carb. You will get more torque from an after market motor with your stock controller and a good battery that won't shut down on you. Your stock controller may be able to have settings changed and that would be like putting bigger jets in your carb. If your stock controller can't be programmed to feed a high torque motor you would have to replace it as well. If you think that is going to happen you may as well go with an AC conversion set up for a few dollars more. If that won't satisfy your need for speed and torque nothing will but it is not cheap. I plan on going with an AC conversion kit at some point and I will have a good DC motor and controller to put in another cart or just sell them to recoup some cash.

Once you get a battery that functions as it should if you are not happy with the performance start looking at motor/controller packages.