48v to 56v upgrade?

[McDx]

I've read a couple threads on people adding a 7th battery running at 56 volts on ezgo carts. I'm wondering about the possibility on our ICONS. Any thoughts?

[ATrain]

Originally Posted by McDx

I've read a couple threads on people adding a 7th battery running at 56 volts on ezgo carts. I'm wondering about the possibility on our ICONS. Any thoughts?

Somebody else mentioned 72v in another thread, which is too much, but it had me look up the controller specs and honestly I think it could work just fine?

Again, I'm not an expert in this space, but the "Remark" appears to say the 20-63V acceptable limit is allowable provided the controller stays between -40℃ and 80℃ (176F to -40F).

So if you have the cable & software, you could try and it and use the monitoring software to watch the temperature of the controller.

[McDx]

I have the programming cable. I will run this test and post the results. Is the state of charge determined by the voltage? Wondering if it will give wrong charge results.

[ATrain]

Originally Posted by McDx

I have the programming cable. I will run this test and post the results. Is the state of charge determined by the voltage? Wondering if it will give wrong charge results.

Good question! So the SOC on the display...that might be programmed into the display firmware and may be stuck thinking 51v is "fully charged". That's just the display though.

In the controller however, there are considerations to be had. If you look at the "Battery Setting" section with lines 39-43 that is where changes would need to be made. Here is where I just noticed something good that supports the idea of an extra battery.

Line #40 - Factory setting used to be 62v, but is now 59v I believe with newer carts. Either way, these numbers support what I read about the acceptable upper voltage range.

It is looking as simple as throwing an extra battery in and you'll be good to go. The only thing would be your lower pack voltage.

Let's say you had six 8v batteries. Let's say when the pack voltage is 37v (Line#43) the cart is considered dead/limp. Well that means your batteries are all at roughly 6.17v/ea.

If you have seven 8v batteries, when the pack voltage is 37v (Line#43), that means each battery is roughly 5.29v/ea!

I'd have to check the battery spec sheet again, but if you let your batteries get that low I would guess you're more likely to damage them faster.

So if you add a 7th battery, I would suggest changing the lower voltage limit, line #43 to 43v. That way 43/7 = 6.14v, which is probably close enough.

I would expect you'd get a noticeably more responsive cart and 15%'ish further range.

[McDx]

All the more reason to have a true RMS voltage readout going on. I want to be able to monitor these batteries closely. I really don't like bringing any lead acid battery below 50%.

Would you think the charger would need any changes to the charge profile?

[ATrain]

Originally Posted by McDx

All the more reason to have a true RMS voltage readout going on. I want to be able to monitor these batteries closely. I really don't like bringing any lead acid battery below 50%.

Would you think the charger would need any changes to the charge profile?

Yup, another thing I hadn't thought about. I would guess the charger is just going to stop at 51'ish volts.

You could possibly use the lithium profile? No clue.

[ATrain]

Some more info regarding charging if you decide to try 56v from my EE BIL:

Charge cycles are constant current for the first half then constant voltage for the end of the charge cycle. That's because if you put the full 58.8v charge to a battery that is fully discharged at ~45v then the charge current would be very high. More than the 10-20 amps that it should be charged that. So that's the constant current part. For the end of the charge cycle, you apply the exact max voltage that is the fully charged voltage. Then the battery slowly trickles to that voltage according to Ohms law.

So those different battery chemistries need various charge profiles to maintain their health. You don't want to throw too much current at it on the low end

[jimbrooks333]

Originally Posted by McDx

I've read a couple threads on people adding a 7th battery running at 56 volts on ezgo carts. I'm wondering about the possibility on our ICONS. Any thoughts?

Howdy ! Wanted to see if you had ever done this and what was needed if so!? If you did, whats your thoughts on the upgrade!?

[capitalst]

How would you wire that 7th 8V battery exactly? Do I need some bracket to hold the battery done? Any pics of the 7th battery installed?

[jimbrooks333]

Spoke to a golf cart mechanic, and not sure of exact details but he advised against doing this for possible controller programming issues, so I stopped really looking into it myself!