Buggies Gone Wild Golf Cart Forum

Buggies Gone Wild Golf Cart Forum (https://www.buggiesgonewild.com/index.php)
-   Lithium Club Car (https://www.buggiesgonewild.com/forumdisplay.php?f=98)
-   -   BigBattery 48v HSKY Discouraging News (https://www.buggiesgonewild.com/showthread.php?t=180268)

Ronno6 10-20-2021 11:19 AM

BigBattery 48v HSKY Discouraging News
 
I just had a chat with the BB tech dept.
I was curious that my battery only charges to an absolute max of 54.6v, and that doesn't last long after beginning operation...
The resting voltage drops to 53.2v VERY quickly.
But, resting voltage will read that for many, many days after that.....
Seems like I always am greeted with a readout of 53.0 on the dash gauge, which is always .2v lower than the readout on the battery....
I was told that 53.2 represents a 99% of max charge.....
I was instructed to run the battery down to low voltage cutoff then recharge.
Do this several times to increase capacity...
However, once the LV cutoff point is reached, I would be dead in the water and have to tow to the shop. Not crazy about that........
Then he said to take it to 20% rather than LV cutoff........

I then inquired as to the state of the Blue tooth app for the BMC. First I got blah, blah, but then was told that, if my IOS device didn't recognize the BMS on BT, IT NEVER WOULD................... So...................
I guess I just have to stay in the dark and drive it.

Not to say that I am unhappy with the HSKY, just disappointed that I was not more informed when I purchased it.

Y'ALL BE ADVISED !!!

Tom47 10-20-2021 04:30 PM

Re: BigBattery 48v HSKY Discouraging News
 
Ronno, I really think that 53.2 resting voltage is what you want to extend the life of your pack. I think you are fine.

53.12 volts is 3.32 volts per cell which is excellent. It may only be 90% SOC but your battery monitor and shunt will configure this as 100%. If you can't get 50 miles with your pack on level pavement, I'll give you a refund....well forget that part.

In the woods where you roam, 50 miles could never be achieved but you are in excellent operating condition anyway. When you get down to a minimum of 51.5 volts, which will be around 20% SOC, recharge it. If I were you, I would recharge when you hit 50% charge. Two 50% charges equals one life cycle.

As far as the bluetooth apps, I don't have that feature and don't even want it. The dash gauges are all I need to see where I am at. As long as my BMS does its thing, I'm happy.

Have I told you I really like my Eco Battery yet?

dc.901 10-21-2021 07:49 AM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Ronno6 (Post 1858311)
However, once the LV cutoff point is reached, I would be dead in the water and have to tow to the shop. Not crazy about that........

Does it have to be driven? I mean what if you turn on the lights or create load other ways?

Ronno6 10-21-2021 08:26 AM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by dc.901 (Post 1858426)
Does it have to be driven? I mean what if you turn on the lights or create load other ways?

I have not as yet installed my voltage reducer.......
But, that is a thought.
Lights are the only accessory on the cart.

WalterM6 10-21-2021 07:16 PM

Re: BigBattery 48v HSKY Discouraging News
 
1 Attachment(s)
Your batteries sound just fine to me.

MaximumOverdrive 10-22-2021 09:17 AM

Re: BigBattery 48v HSKY Discouraging News
 
Mine charges to 54.6 with a Lester Summit II charger. It seems okay to me, I drove my cart on a 20 mile run last week. I think it could have gone another 10 miles or more.

CP241 10-22-2021 03:48 PM

Re: BigBattery 48v HSKY Discouraging News
 
I think you’re good also. I’ve got allied 60aH and it comes to rest around 54.5-54.7v after a full charge. I’ve been told by allied a resting voltage of 51.2 is “dead”. I’ve never run them that low; I’ve gotten 30+ miles on a charge and it rest at 51.6ish IIRC. I usually recharge around 52v range.

I had to send about 15 emails back and forth with allied before I was able to get any specs from them re low and high voltage cutoff, temp operation, etc. I had to ask very specific questions to get specific answers (and even then, they satisfied what I was looking for but still what I would define as “specifically vague” answers…)

Ronno6 10-22-2021 05:38 PM

Re: BigBattery 48v HSKY Discouraging News
 
Hmmmm, the chart indicates that 53v is about 75%......
BB said that 53v is 99%
That is quite a discrepancy IMO

Pat911 10-22-2021 06:34 PM

Re: BigBattery 48v HSKY Discouraging News
 
Predicting SOC via voltage is highly inaccurate with LiFePO4.

Tom47 10-22-2021 07:54 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Pat911 (Post 1858739)
Predicting SOC via voltage is highly inaccurate with LiFePO4.

I've noticed this and have thrown out all my SOC charts. I made a 29.25 mile run today as a test with my 72 Ah battery:

Ending SOC on meter 39.4%

Ending Volts on meter 52.31

Ending Ah on meter 28.4

The voltage according to my charts was around 55%SOC. Could that possibly be correct and my SOC meter incorrect? I think as you said the voltage is not a good indication of SOC.

Then what is correct in these three readings?

Tom47 10-22-2021 07:58 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Ronno6 (Post 1858729)
Hmmmm, the chart indicates that 53v is about 75%......
BB said that 53v is 99%
That is quite a discrepancy IMO

BB is correct. That is about 3.31 volts per cell which would be 90+ % depending on the decimal amount.

I think all of the charts for lifepo4 are incorrect. Especially the ones I made!!!:oops:

Maybe? The charts I made said 100% but this is actually 80% or 53.2 volts. My meter is calibrated to show the resting voltage as 100%. Maybe that is the discrepancy.

Volt_Ampere 10-22-2021 08:49 PM

Re: BigBattery 48v HSKY Discouraging News
 
Given the voltage variation with temperature and cycle history, trying to measure SOC by voltage is not very useful with lifepo4 batteries. You need to count electrons.

Tom47 10-22-2021 09:19 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Volt_Ampere (Post 1858758)
Given the voltage variation with temperature and cycle history, trying to measure SOC by voltage is not very useful with lifepo4 batteries. You need to count electrons.

Tough to do for sure. Would you say it is more accurate to measure SOC by remaining Ah instead of voltage? It appears to be fairly consistent in my mileage log. Voltage has been all over the place but SOC and Ah are more predictable.

I rode 29.25 miles today and had ending Ah of 28.4. So I used 43.6 Ah which approximates to 1.49 Ah per mile. This has been pretty consistent in 10 logged rides of over 8 miles. 1.42 to 1.60.

Variations may be due to average speed. Faster average speeds seem to have used more Ah per mile. Temperature has been between 65 and 90 however which may throw everything off.

Volt_Ampere 10-22-2021 09:45 PM

Re: BigBattery 48v HSKY Discouraging News
 
Measuring Amp Hours (counting electrons) is the only way I know to get a reasonable measure of SOC with these cells. A good BMS will do that for you but it isn't easy with the wildly fluctuating current in a golf cart while driving. It's easy when charging to measure how much you put in but you really need to know how much is left while driving.

Pat911 10-22-2021 11:46 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Tom47 (Post 1858749)
I've noticed this and have thrown out all my SOC charts. I made a 29.25 mile run today as a test with my 72 Ah battery:

Ending SOC on meter 39.4%

Ending Volts on meter 52.31

Ending Ah on meter 28.4

The voltage according to my charts was around 55%SOC. Could that possibly be correct and my SOC meter incorrect? I think as you said the voltage is not a good indication of SOC.

Then what is correct in these three readings?

Hi Tom,

Forget the voltage. 39.4% of 72Ah is equal to 28.4Ah, so both these numbers (39.4% or 28.4Ah) are what I would be going with.

As Volt_Ampare implied, your SOC meter counts electrons, go with that.

Cheers
Pat.

Tom47 10-23-2021 07:04 AM

Re: BigBattery 48v HSKY Discouraging News
 
1 Attachment(s)
Thanks Pat and V_A!

As usual, you start helping someone else with their problem and end up helping me!

I think it is starting to sink in now.:thumbup:

Tom

And this is my new charging chart:

Pat911 10-23-2021 02:47 PM

Re: BigBattery 48v HSKY Discouraging News
 
No voltages Tom……I like it. :lol::thumbup:

Tom47 10-23-2021 03:24 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Pat911 (Post 1858863)
No voltages Tom……I like it. :lol::thumbup:

Thanks, Pat! Gosh, this makes it so much easier.:thumbup:

MaximumOverdrive 10-24-2021 02:55 PM

Re: BigBattery 48v HSKY Discouraging News
 
My cart only needed a 48Ah recharge after the 20 mile run it did last weekend. I only recharged it today too. I think it could probably go 40 miles on a full charge.

Tom47 10-24-2021 03:37 PM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by MaximumOverdrive (Post 1859009)
My cart only needed a 48Ah recharge after the 20 mile run it did last weekend. I only recharged it today too. I think it could probably go 40 miles on a full charge.

That is 2.4 Ah per mile. With 82.4 usable Ah down to 20% SOC (105Ah minus 20% = 82.4), you should see 34 miles. If you take it down to 5% SOC you would see 41.6 miles, although I don't like running it that low. Close to home, no problem.

I am getting a mile every 1.48Ah. You apparently have more Ah consumption due to the larger tires and higher speed.

I recommend keeping a log of any ride over 5 miles. This will give you a good indication of what to expect in future rides. I charge after any ride of 5 miles or longer. That's about a 10% DOD. Ten of these charges would equal one life cycle.

I'm glad your cart is working great for you. I know you're as glad as I am about going to lithium.:thumbup:

MaximumOverdrive 10-25-2021 08:12 AM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by Tom47 (Post 1859013)
That...

That's quite a difference in energy draw between our two carts. I want to run an AC motor eventually to give my cart a bit more range.

I use a tracking device to keep trip logs. I would highly recommend one to anyone interested. They'll tell you how far you go and they have good security features. Mine is made by Optimus, but there are many that do the same things mine does.

Tom47 10-25-2021 08:30 AM

Re: BigBattery 48v HSKY Discouraging News
 
Quote:

Originally Posted by MaximumOverdrive (Post 1859113)
That's quite a difference in energy draw between our two carts. I want to run an AC motor eventually to give my cart a bit more range.

I use a tracking device to keep trip logs. I would highly recommend one to anyone interested. They'll tell you how far you go and they have good security features. Mine is made by Optimus, but there are many that do the same things mine does.

Never thought about trip tracking devices. I'll need to look into those. Thanks!


All times are GMT -5. The time now is 09:34 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
This Website and forum is the property of Buggiesgonewild.com. No material may be taken or duplicated in part or full without prior written consent of the owners of buggiesgonewild.com. © 2006-2017 Buggiesgonewild.com. All rights reserved.