More volts !!!

[Dragracer_Art]

Here's what I have in mind...

(Again, my 12v converter is rated 48-72v)

[scottyb]

A trickle charger will not properly maintain a golf cart battery.

[Tsteak]

A trickle charger is meant to maintain an already mostly full charge on a battery that is not designed to discharge much, as in a car or motorcycle where it simply starts the vehicle and operates lowV stuff and is recharged by the alternator. It won't work for you.

Point of reference: when the battery on my dump trailer eventually ran out of juice from sitting idle for too long; it took a "Battery Tender" charger about 3 days to charge it back up. Those things are meant to keep this from happening, not actually charge a significant amount. It won't be able to keep up with your use. You'll prolly need to find a programmable charger for the whole pack, if you can.

The juice ain't worth the squeeze. Build a lithium pack instead, bite the bullet!

-I am going to follow this though, interested to see how this sugars out, you seem quite determined...

[Dragracer_Art]

Yeah... I dont know.
I already have the 8v charger sitting here... but have multiple things bouncing around in my skull... from adding a 7th 8v battery... to building a leaf lithium pack... to going navitas 72v ac conversion... to doing nothing.


If I sit on it long enough... I will settle on something.

[Dragracer_Art]

Any reason I couldn't use something like this and adjust the trim pot for proper output voltage ?
It looks like it is compatible with lead acid batteries.
I see it is popular with the lithium guys.

https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1

or this one...

https://www.ebikes.ca/product-info/cycle-satiator.html

[bronsonj]

Originally Posted by Dragracer_Art

Any reason I couldn't use something like this and adjust the trim pot for proper output voltage ?
It looks like it is compatible with lead acid batteries.
I see it is popular with the lithium guys.

Lithium can charge on minimal amperage. Lead acid needs to bubble to stir the electrolyte. If you are going with one of those then get the larger amperage one and check what your batteries should charge to.

But, your building a 7 battery pack with 6 older batteries and one newer battery. When you discharge the pack, the older batteries will discharge more than the newer battery as they will have less capacity than the new battery. When you charge the pack the newer battery will be closer to full charge so it will get overcharged. This will cause your new battery to age much faster until it matches the apparent age of the other batteries.

If you do add another battery that you then charge on it's own circuit it avoids this problem. But you have to charge it with sufficient amps to agitate the electrolyte (ie, more than a trickle charge).

But... You are looking for an excuse to put in a lot of effort to get a little more performance out of your cart. Why not put in the same effort (although more $) but get a lot of performance? A 14S pack made of Leaf cells (or Chevy Volt cells if you want to be different) will dramatically reduce the weight of your cart (for better acceleration), increase the voltage (better top speed and accel) and dramatically reduce voltage sag (for better acceleration).

[Dragracer_Art]

Originally Posted by bronsonj

Lithium can charge on minimal amperage. Lead acid needs to bubble to stir the electrolyte. If you are going with one of those then get the larger amperage one and check what your batteries should charge to.

But, your building a 7 battery pack with 6 older batteries and one newer battery. When you discharge the pack, the older batteries will discharge more than the newer battery as they will have less capacity than the new battery. When you charge the pack the newer battery will be closer to full charge so it will get overcharged. This will cause your new battery to age much faster until it matches the apparent age of the other batteries.

If you do add another battery that you then charge on it's own circuit it avoids this problem. But you have to charge it with sufficient amps to agitate the electrolyte (ie, more than a trickle charge).

But... You are looking for an excuse to put in a lot of effort to get a little more performance out of your cart. Why not put in the same effort (although more $) but get a lot of performance? A 14S pack made of Leaf cells (or Chevy Volt cells if you want to be different) will dramatically reduce the weight of your cart (for better acceleration), increase the voltage (better top speed and accel) and dramatically reduce voltage sag (for better acceleration).

The 6 Trojans that are in it are only a month old... so adding a 7th would be a non-issue.
This is the only reason I havent gone to a Leaf pack yet... because I just spent $1000 on the 6 lead acid batteries I have. (no cores to trade)

If I could find another $300 cart that needs a set of batteries... I could justify the expense of a lithium pack and just roll these Trojans into another cart.

I have been reading alot on the lithium stuff though... so once I know a little more about them it may be an easier decision to make.
Right now that is alien tech to me... and lithium melt-downs scare the crap out of me. My cart spends 99.99% of it's time inside my garage... and if it has a battery melt-down, it will burn my house down.

[bronsonj]

Originally Posted by Dragracer_Art

The 6 Trojans that are in it are only a month old... so adding a 7th would be a non-issue.

ok, so then I'd email or call Lester to see if they can sell you a 56V charger for your seven 8v pack. If you can't solve the charging issue then you can't expect to have a pack that will last.

Your choices are a 56V pack with a 56V charger (seven 8V). A 56V pack with a 48V charger and another 8V (not trickle) charger. If you can't find a charger you will be throwing away the $ from the pack.

Now, they do have 6V chargers and as much of a Frankenstein as it would be you could have six 8v and one 6v battery in the pack. The six 8v on one charger and the one 6v on another.

[Dragracer_Art]

Originally Posted by bronsonj

ok, so then I'd email or call Lester to see if they can sell you a 56V charger for your seven 8v pack. If you can't solve the charging issue then you can't expect to have a pack that will last.

Your choices are a 56V pack with a 56V charger (seven 8V). A 56V pack with a 48V charger and another 8V (not trickle) charger. If you can't find a charger you will be throwing away the $ from the pack.

Now, they do have 6V chargers and as much of a Frankenstein as it would be you could have six 8v and one 6v battery in the pack. The six 8v on one charger and the one 6v on another.

Just sent an email to Lester Electrical. Will see what they come back with.

[Dragracer_Art]

Already got a reply from Lester.
(My similar email to DPI was never answered.)

"Lester Electrical does not make 56 Volt Chargers. 48 VDC is the maximum voltage that we support.

I will add you request to a growing list of requests for higher output chargers, but it may be some time before decision is made to accommodate the product changes."