battery usage confused

[flharleycop]

I am trying to figure out what my range is on my cart so over the last three days I traveled 26 miles on one charge. At the start I had 38v reading of all batteries once I took it off the charger and drove it a little bit. I drove it 26 miles some of it at night with all the lights on over a three day period it was maintaing my best top speed of 19 mph the whole time. The dash gauge moved to slightly above half way so I figured I would charge it tonight but wanted to see how much battery I had left. The meter read 36.4 volts, I am confused it has traveled 26 miles sat and ran over three days and it has shown no loss of speed. i don’t want to run it down further as the 26 miles will do what I need it to do with some extra range.
Can someone help me understand why there is so little loss of volts? I was expecting half gauge so there to be around 18v left.

Thanks,

[Knothead]

Your batteries should be around 38.2 volts @ 100% charge & 36.3 volts @ 50% charge. You should NEVER run it below 50%.......in fact it is highly recommended to recharge @ 70% SOC, which is 37.1 volts.

[flharleycop]

Originally Posted by Knothead

Your batteries should be around 38.2 volts @ 100% charge & 36.3 volts @ 50% charge. You should NEVER run it below 50%.......in fact it is highly recommended to recharge @ 70% SOC, which is 37.1 volts.

I just rechecked the cart I have 36.3 volts left now and the meter is about half way. So I put it on charge, the question is if I was at this same point and I was out running around in it, could I make it 5 miles home maintaing close to the same speed and would that harm the batteries?

[Knothead]

I figure JohnnyB will chime in shortly. He's very knowledgeable about batteries & stuff. I don't run mine down as far as you already have. The lower you run them down before charging them, the harder it is on them, & the shorter the life. Here's a chart he likes to share which shows SOC levels:

[flharleycop]

Originally Posted by Knothead

I figure JohnnyB will chime in shortly. He's very knowledgeable about batteries & stuff. I don't run mine down as far as you already have. The lower you run them down before charging them, the harder it is on them, & the shorter the life.

I needed to check the range, I want to use it on the beach, 5 miles there, 5 miles back plus driving up and down on it checking out the sites!!!

[Knothead]

Originally Posted by flharleycop

I needed to check the range, I want to use it on the beach, 5 miles there, 5 miles back plus driving up and down on it checking out the sites!!!

He & ScottyB will also recommend that you get a real voltage meter , which shows "real-time" voltage. You can then see exactly what your remaining voltage is, instead of relying on a "Full", "Half", etc. Yours seems to be pretty close. Just remember that never going below 50% ("Half" on your gauge) is highly recommended......Actually, charging after you've used even a small amount is recommended to keep batteries healthy. So in essence, if you ride it 5 miles one way, run around another 5, then ride it back 5 miles, you need to plug it up to charger. If you got 26 miles @ 50% SOC, you'd probably be @ 70% SOC at 15 miles.....

[yurtle]

In addition to never running it down that far, the most harmful thing you can do to your batteries is to leave them in that state. If you need to run them down that far, you should always try and fully charge them as soon as possible, no matter how far down you run them. Leaving them in an undischarged state for days will cause permanent damage.

[JohnnieB]

There is only 2/10 of a volt difference between a fully charged and a full discharge lead-acid cell. There are 18 x 2V cells in a 36V battery pack, so do the math.

Recharge your batteries after each use, or at least every night after the cart is used that day.

From what you've said, you can get about 26 miles without going below 50% SoC, so every day you can go to and from beach (10 Miles round trip) and have about 15 Miles of beach cruising.

To have more cruising range on the beach, you will have to carry more Kilo-Watt Hours (Volts times Amp-Hours) with you.

I wanted more range, so I opted to increase both the Amp-Hour rating on the batteries and the number of batteries in the pack.
I haven't got it put together yet, but I calculate I'll have well over a 30 mile (round trip) range when I do.

[flharleycop]

Originally Posted by JohnnieB

There is only 2/10 of a volt difference between a fully charged and a full discharge lead-acid cell. There are 18 x 2V cells in a 36V battery pack, so do the math.

Recharge your batteries after each use, or at least every night after the cart is used that day.

From what you've said, you can get about 26 miles without going below 50% SoC, so every day you can go to and from beach (10 Miles round trip) and have about 15 Miles of beach cruising.

To have more cruising range on the beach, you will have to carry more Kilo-Watt Hours (Volts times Amp-Hours) with you.

I wanted more range, so I opted to increase both the Amp-Hour rating on the batteries and the number of batteries in the pack.
I haven't got it put together yet, but I calculate I'll have well over a 30 mile (round trip) range when I do.

If I were to eventually get the upgrade with the Altrax to get my speed up, keeping my 36v system. How much range do you think I would loose?

[Sir Nuke]

Originally Posted by flharleycop

If I were to eventually get the upgrade with the Altrax to get my speed up, keeping my 36v system. How much range do you think I would loose?

before an answer can be given to that question.....what type of drive system does your cart have? is it a series moter ? or a sepex?

http://www.buggiesgonewild.com/elect...en-system.html