Are these battery manufacturers just making up specs?

[Davids29]

So, I am new to golf carts, but not electronics, lithium batteries, and electric motors. I was looking through all the specifications of these lithium battery manufacturers, and I think they are just making up numbers as far as the amp draw ratings go, in order best their competitors to sell batteries.

Lets start with the 48V 105AH category. Looking through the battery's on the market, I see this is a common size and flavor of the month. It's a good capacity and physical size for a golf cart. I started looking into which cells they could be using, as I have not found a picture of one taken apart to see the actual cells used. When I start searching these individual cells, I see that almost every one of the 3.2V 105AH cells is actually only rated for 1C continuous, and 3C for 30 seconds discharge. These are the manufacturers specs. So doing some pricing, I can build a pack for about half the current going rate including a nice BMS and charger.

My real question, are the big box battery manufacturers just cooking the numbers and hoping they don't have to warranty very many batteries when they fail? I mean, its not a bad business practice. Most of these batteries are going into stock or slightly modified carts, and in reality, nobody is going to go through 3000-5000 charges in the warranty period. If they just put larger amp limits on their box and warranty the broken batteries as they happen, they can make a lot of profit. If they have the whole assemblies built in China using lesser quality internals, the profit goes even higher.

The truth is, the cells can probably be pushed as hard as the numbers state, but the life will be less, not a bad trade off really. So far, even contacting a few cell manufacturers, I can't find a single one that will warranty the cells at the rates I see on some of the packs on the market.

So, what do we think? Fudging the numbers and hoping for the best?

[Volt_Ampere]

The real issue is what quality cells are these vendors using? None of them manufacture the cells so they are sourcing them from China. You can get all sorts of different quality cells from China. Some are not even close to their specs. Just watch some of the forums that deal with Battery banks and you will see that it's a crap shoot.

[simicrintz]

As you can see from my signature (which I need to change), I built a Chevy Volt setup for my cart. I couldn't really find an "out of the box" battery at the time that I was comfortable with. I've been building stuff for 45 years now, and electrical is my weakest suit. With the help from some good folks on here I was able to properly and safely complete my build, and I was happy with it.

I did have a code flashing on my Curtis controller, and since Eco Battery is right around the corner from my house, I stopped in one day and asked if they could diagnose and help, or point me in the right direction. Noah said to just drop the cart off one day and that they would look at it for me (I bought nothing from them-this was just a very generous offer from Noah). Long story short, I now (as of yesterday) have an Eco Battery 48V 105 Ah battery in the cart. Top speed went from 28 mph to 34 mph, and the cart definitely seems stronger off the line.

As lithium gains momentum, I suspect more and more suppliers will enter the market, and tales will be told. I regarded my Volt batteries as quality units (still do), but I see better performance from the Eco Battery already. Don't know that I need to know how they build them, or what the individual cells are; the seat of the pants results are clear, and I do appreciate their 8 year warranty.

Good luck in your studies and decision-I'll throw my vote behind the gang at Eco for your consideration (they are Site Sponsors as well)

[augiedoggy]

actually they are typically rated for 3c max.... It does effect battery life when a steady current larger than even .5c is placed on them but they are fine at 3c.

From what ive been reading, if anyones exaggerating from what I can find it the folks selling 5-600amp controllers claiming they will make a huge difference when most of the actual tests that ive been able to find data on indicates that golf carts typically dont go over 100 amps draw unless climbing a hill or under a large load and then its typically only for a very short period.

Many of these preassembled lifepo4 batteries are limited with a low 100amp BMS the ones typically built for 36 or 48 v and for goft carts typically have a larger bms.

I have 16- 90amp cells on the way and a 500a bms rated for 240amps continuous and I went for the eve 90amp cell vs the 105ah because they are actually rated for a higher continuous c rating (and they were on sale for $623) I spent the last 2 months researching different cell suppliers before taking the risk buying these but they have 28 of of 30 positive reviews for these particular cells.

Its more than just the "Amp" ratings that make lithium work better.. Its the instant on demand current thats there vs lead acid which suffers from the peukart effect. I had 6 225ah golf cart batteries in my camper in a solar setup and I could only run my coffee maker for less than 10 minutes bufore the inverter would cut out with an undervoltage condition... same coffee maker with a new 230ah lifepo diy battery I built this spring and the coffee maker doesnt even phase it. in fact according to the current draw and estimated time remaining on the bms I could run the coffee maker for over almost 3 hours with no issue. the voltage does not sag like it did under large load with lead acid and the battery doesnt over heat.

[Pat911]

EVE cells are some of the best on the market. Good choice.

[augiedoggy]

Originally Posted by Pat911

EVE cells are some of the best on the market. Good choice.

I made a 230ah pack with them this spring for my pop up and they have surpassed my expectations.

[augiedoggy]

These are the cells I went with... as you can see they are only 90ah but rated for 200amps continuous which they will never see and 300amps for 60 seconds.. The alltrax controller im installing is only rated for 125amps continuous.
https://www.gobelpower.com/eve-32v-9...ersion_p3.html

[WalterM6]

This is what I see wrong with those EVE batteries. They only have an M4 thread for the electrical connections. This makes it very easy to strip the aluminum threads out of the battery. I wound up using Helicoils to repair them. They are now used for my solar setup because they can't supply high currents.

[WalterM6]

EVE cells are some of the best on the market.

My preference is CALB batteries.

[augiedoggy]

Originally Posted by WalterM6

This is what I see wrong with those EVE batteries. They only have an M4 thread for the electrical connections. This makes it very easy to strip the aluminum threads out of the battery. I wound up using Helicoils to repair them. They are now used for my solar setup because they can't supply high currents.

Honestly my cells are connected to a bms and external connection from that is a large anderson connecter so its not an issue for me.
Also my eve cells from docan came with stubs and bolts so that makes stripped threads even less likely.