Why NOT Lithium instead of FLA?

[scottyb]

Are these lithium iron phosphate (LiFePO4) battery batteries?

[ONEDAY]

Originally Posted by scottyb

Are these lithium iron phosphate (LiFePO4) battery batteries?

Here they are



http://hybridautocenter.com/HAC4/ind...-15&Itemid=605

[Volt_Ampere]

If you have a good BMS that keeps the cells balanced, you can take lithium down to 20% SOC routinely. The 7 module pack is just over 60AH. That will get you two solid rounds of golf. Yes it's more expensive but you gain performance and there is no mess. Lithium is going to come down in cost as more are produced. The Lipo batteries I use for my electric model airplanes were $80 each ten years ago and they are now more like $20 with better performance.

[rabbitreborn]

Originally Posted by Volt_Ampere

If you have a good BMS that keeps the cells balanced, you can take lithium down to 20% SOC routinely. The 7 module pack is just over 60AH. That will get you two solid rounds of golf. Yes it's more expensive but you gain performance and there is no mess. Lithium is going to come down in cost as more are produced. The Lipo batteries I use for my electric model airplanes were $80 each ten years ago and they are now more like $20 with better performance.

Maybe I am dumb as a box of rocks, but other than the vehicle weighing less, I fail to see a performance gain. Yes, everyone reports their carts as being "faster" on Lithium, but they also are using a higher voltage pack, so you expect a faster cart. That's no different than the performance enhancement of a 36v cart with 48v batteries in it..... logic says you will see an increase in speed due to the higher voltage.

[Volt_Ampere]

More volts and less internal resistance == performance gain. Minus 250lbs is a big performance gain. A 7 module Leaf pack gives you at least a couple volts more than a 48V FLA pack. (58.8V at full charge - 4.2V per cell) Believe me it makes a huge difference.

[JohnnieB]

Originally Posted by rabbitreborn

Maybe I am dumb as a box of rocks, but other than the vehicle weighing less, I fail to see a performance gain. Yes, everyone reports their carts as being "faster" on Lithium, but they also are using a higher voltage pack, so you expect a faster cart. That's no different than the performance enhancement of a 36v cart with 48v batteries in it..... logic says you will see an increase in speed due to the higher voltage.

The Peukert factor for Li batteries is very close to 1.0 and there is just about zero voltage drop under load, so performance is better during acceleration, going uphill and in other situations where loading causes a LA battery pack to drop in voltage.

If you could create a LA and Li battery packs that had exactly the same at-rest voltage and installed them in carts with exactly the same mechanical drag, the one with the Li pack would be a bit faster and get there a bit sooner. How much faster and how much sooner probably is only a few percentage points.

However, since a typical Li battery pack is higher in voltage and weighs less than a LA battery pack, the modest gains due to the difference in the Peukert factor are overshadowed by the more obvious differences in weight and voltage.

[scottyb]

I'm all for new technology but, it didn't take much research to find a lot of info on what the industry calls the dangers of lithium batteries.

[Volt_Ampere]

All batteries must be handled with care. FLA batteries blow up frequently due to Hydrogen gas generation during charging. Some lithium formulations are more unstable than others and all of them require proper charging profiles. Almost every laptop and every cell phone has lithium batteries in it. Most power tools use Lithium technology now. Most electric cars are lithium. (not hybrids but electrics or plug-in hybrids) Most of the Tesla fires have been caused by running over something and having it puncture the battery pack. I consider them safe for golf cart use if handled properly.

[scottyb]

Originally Posted by Volt_Ampere

All batteries must be handled with care. FLA batteries blow up frequently due to Hydrogen gas generation during charging. Some lithium formulations are more unstable than others and all of them require proper charging profiles. Almost every laptop and every cell phone has lithium batteries in it. Most power tools use Lithium technology now. Most electric cars are lithium. (not hybrids but electrics or plug-in hybrids) Most of the Tesla fires have been caused by running over something and having it puncture the battery pack. I consider them safe for golf cart use if handled properly.

"FLA batteries blow up frequently", really? Frequently? Well at least I agree on one point - a hand-grenade is safe if handled properly
We all know the quick fill tubing can collect hydrogen gas so we all avoid using it - danger eliminated.

[Volt_Ampere]

I have personally seen two FLA explosions when I was working on electric cars back in the 70's. There have been several related in this forum. It does happen. Batteries have a lot of stored energy that if released improperly can do damage - just like a car's gas tank has lots of stored energy. I am not saying our stuff is unsafe - just that you have to treat it with respect - not unlike a hand-grenade.