48v battery questions

[DeadZone]

Originally Posted by Bama Brad

Why not replace with the Roypow Lithium 48v 105ah pack, you get a charger and BMS with it. $2,000 for lithium (and new charger) vs $1700 plus for just batteries? Save $$ in long run and make cart 450 lbs lighter.

I know nothing about these but my concern is whether the lights, etc will work the same. I figured this cart had 6v batteries because it had 6v bulbs, etc?? Probably a stupid assumption.

The 6v batteries I have are 283ah batteries, wouldn't a 105ah run out quicker? The cart is technically a street legal car that goes 25 mph.

[DaveTM]

Originally Posted by DeadZone

I know nothing about these but my concern is whether the lights, etc will work the same. I figured this cart had 6v batteries because it had 6v bulbs, etc?? Probably a stupid assumption.

The 6v batteries I have are 283ah batteries, wouldn't a 105ah run out quicker? The cart is technically a street legal car that goes 25 mph.

Ok.....well, the 6V batteries you have were rated (were being the key word) at 283AH, but they are as dead as a door nail so you really don't have anything. (I'm not trying to be snarky here......just stating the facts)

Before I switched to Lithium I ran 8 Trojan T-105's which were rated at 225AH. When I switched to lithium (initially) I installed a 7 module Leaf 60AH pack. My cart had the same "run" and "distance" capacity with the 60AH lithium as it did with the 225AH Trojan's.

Why? Because it's the usable amount of energy that matters. That, along with losing 400-lbs when going from 8-FLA's to a 7 module Leaf. With FLA's you only have a maximum usable volt range from 2.122-VPC to 2.017-VPC. In other words don't drop below a 50% SOC with FLA's.

With lithium a max per cell volt is 4.1. (Actually 4.2) and the lowest a cell should go to is 3.5. If a lithium cell drops below 3.14-V the battery is likely damaged and in a very dangerous state. So....what I'm saying without being techno is it's tough to compare the two types of batteries and state this in layman's terms. (Or my terms)

Also, since I just doubled my pack to 14 modules and increased my amp\hr from 60 to 120, I have twice the energy storage I had before. Same voltage....just more energy. For an example, if you hooked up 16 FLA's you would have twice the energy storage as you would with 8 FLA's. But you also have 500+-lbs of weight along with that.

Now.....I've oversimplified this as it's not just a "volt" thing but the storage capacity of energy. The storage capacity is measured in amp\hr and a lithium battery has a greater "useable" storage capacity than the FLA's. Again....I'm likely oversimplifying this as I'm no engineer and just a novice. Those in the know will chime in and state where I'm not quite technically right.

But I hope this helps.

[Fairtax4me]

I would guess the previous owner put the high capacity batteries in there, because those are very expensive batteries, and was probably done to get extended range.

There would be less range with a lithium pack at 105Ah. But there are other factors to consider for lithium, such as power demand from the motor. I'm sure you could get away with a 100Ah lithium pack, but for the extra cost, I don't think it would result in greatly extended range.
If you're just planning to run around your neighborhood, a set of Trojan T-105 batteries should still get you in the 30+ mile range, for much less cost than the super high capacity batteries. You would be spending about $1200 on batteries, vs nearly $1800 for the higher capacity lead acid, or $2000+ for a comparable lithium pack.
If you think you'll keep the cart for 10+ years, then a lithium pack might make sense. But if you take care of lead acid batteries, a set of Trojan batteries can last 8 to 10 years depending on your usage and maintenance habits.

[Fairtax4me]

With lithium a max per cell volt is 4.1. (Actually 4.2) and the lowest a cell should go to is 3.5. If a lithium cell drops below 3.14-V the battery is likely damaged and in a very dangerous state. So....what I'm saying without being techno is it's tough to compare the two types of batteries and state this in layman's terms. (Or my terms)

This is dependent on the type of lithium battery. What chemisty are the Leaf cells? the "drop-in" batteries that most companies are marketing now are LiFePo4 which have less energy density than say a Lithium Cobalt, or LiPo cell. They are slightly safer chemistry in that they are less likely to burn your house down if they are run below threshold, and the drop in packs also tend to have a built in low voltage cut-off and BMS. Vs the DIY packs that most people build have a separate BMS and LVC that are designed with high amp draw in mind. Most Drop in packs cant supply large amounts of current due to the limitations of the battery chemistry. Thus they are typically only rated for Golf use, on a stock cart, where power output is typically limited, and you're in a "safe" area, on private property. The drop-in packs can also have issues when electrical demand surpasses the battery's safe ability to supply amperage, the cut-off kicks in and kills the cart. Of course the range of the battery and power/amperage demand also is dependent on what motor the cart has. A higher power motor will always need more amperage, and thus a battery capable of supplying that without shutting off.
I don't know what kind of motor would be in a Zone cart. But probably not the same motor that's in a normal fleet golf car made for riding around on the course at 13mph.

[DeadZone]

Originally Posted by Fairtax4me

I would guess the previous owner put the high capacity batteries in there, because those are very expensive batteries, and was probably done to get extended range.

The 283ah batteries are original, I am the original owner of the cart. Just haven't taken care of it and it has sat for a long time. The cart is actually a street legal "car" which is governed to 25mph.

If I went with 180ah batteries which I can get locally, will it still hit 25mph but not keep as long of a charge or will it have less overall speed?