Battery options

[MC1]

Originally Posted by jjance

About 30 mins

That's what i thought.

[MC1]

I'm getting info from suppliers that a 60aH lithium system will get 25 miles? Are they just optimistic?

[Volt_Ampere]

I think the 60AH system might be marginal but doable. I plan to do a 120AH system (at least 100AH) I have not decided on a total system yet but I have to do it quickly because my batteries are starting to die. I think you could get 25 miles on a 60AH system though. With Lithium I want plenty of margin but I could probably get by with a 60AH system also.

[Volt_Ampere]

One thing about Lithium is that you can use more of the capacity without reducing the life as long as you don't take any cells below their minimum voltage. A good BMS system should prevent that. The other important issue is to make sure that you have a safely designed system. Overcharging can cause a very serious outcome. I plan to have at least two means of preventing that. (Charger and BMS)

[MC1]

The only reason to even think lithium is right now i have nothing. No cores, no cables. No. Tie downs. No charger

Its going to be either:
6-8volt with a charger (will have to do the 4-12v to 6-8v conversion) with new lead acid batteries and a new charger.

Lithium 60Ah 48v system

The lithium system is a bit more money, but if i can get decent run times at 60Ah , should be a strong consideration.

Not using this as a golf cart for a course but a Low Speed Vehicle for running around the neighborhood and close to home errands.

[Volt_Ampere]

I would go with the 60AH lithium system then.

[Oneunder]

FWIW, I have the 60 ah leaf pack on my 2006 Precedent. I have no BMS. My Quick Charge charger is the HVC at a very conservative 4.1 volts/cell charge. I drive a mile to the golf course, play 18 holes ( this course has many hills) and then drive home. On top of that I have a 400 lb enclosure and a 250 lb golf partner. After all that I have a charge of 3.85v/cell. I monitor my charge with a digital volt meter in the dash. 7 leaf modules and charger and dash DVM is pretty economical. And yes, you ditch the OBC. All 7 modules fit comfortably in one side of your battery tubs.

[Volt_Ampere]

I am curious! Oneunder, what charger are you using for your Leaf Pack? How do you maintain cell balance? 4.1V per cell is not conservative unless you monitor all cells and keep the highest one to this max voltage. (Max recommended for these cells is 4.2V) I am researching this and I plan to do a Lithium conversion shortly. I am still deciding between 60 and 120 AH.

[MC1]

Originally Posted by Oneunder

. After all that I have a charge of 3.85v/cell.

Excuse the ignorance but are are you saying that you still have a lot of life left in that system, or are you pushing the limits? We are not going to use this for golfing, just running around the local neighborhood and quick errands to the local store.

Suppliers are saying 25 miles on a 60ah system.

[Volt_Ampere]

For those batteries (Nissan Leaf) 3.85V /per cell is about 40% of a full charge. I would not want to run them down much further than that. I would never want to go below 20% unless I had a very good BMS that prevents any cells from going too low. One time too low will kill a lithium cell deader than dead.