08-08-2022, 01:10 PM | #1 |
Gone Wild
Join Date: Jan 2013
Posts: 164
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Are Ah needs the same?
I am about to have to replace a set of batteries as they have hit well above their cycle life (only 3 years though) and looking at making the lithium conversion. Currently I am running 48 volts through Crown CR-190 batteries with the higher Ah ratings. I talked to my local cart guys the other day and they are selling a good many 60Ah set ups and have not had any come back yet unhappy. I am on a mix of hills and number of kids riding. A regular week is typically 5 days a week of 6-15 miles of riding with 2-6 people on the cart. I get I will lose 300 or so pounds with the conversion, but do I need to be looking at the 105 Ah and up type set ups, thus basically doubling the up front cost of FLA batteries? I don't want to skimp and regret it and still have to spend money again.
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08-08-2022, 07:52 PM | #2 |
Gone Wild
Join Date: May 2012
Location: Rio Verde, Az
Posts: 7,121
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Re: Are Ah needs the same?
I would not go less than 100AH for Lithium. I have been running Lithium for 6 years. Lower AH batteries tend to be underrated for current draw required for carts.
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08-09-2022, 06:35 AM | #3 |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
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Re: Are Ah needs the same?
if you like the higher capacity of good lead acid batteries why then would you go with the smaller lithium pack? If you do and decide you need more it's a much more expensive upgrade to do twice...
As VA said, 100 amp hours is the usual minimum. My pack is a smidge less at 94 so it's really close and I've loved it. But my pack is a custom build so my peak draw and continuous draw are not limited by a substandard BMS, it's limited by my cells and the traction cells I used can provide far more current than my cart needs. After the conversion you may find that the ride is harsher after you lose 300+ pounds. I lowered the air pressure in my tires and I switched from HD springs to Dual Action springs. That made a HUGE difference. The only time I wish I still had HD springs is when I pull a heavy trailer. |
08-09-2022, 08:24 AM | #4 |
Happy Carting
Join Date: Dec 2007
Location: Southern California
Posts: 73,356
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Re: Are Ah needs the same?
Ah (amp hours) is fuel which equals run time. The inherent higher voltage of a lithium battery equals reduced amperage use. Read that again because OHMS law, volts + amps = watts
The more voltage you have the less amperage you need to produce the same wattage (work). That being said. We are running the Eco 51v/72ah pack in our big tire, big motor Ezgo off and on the road. The result is better performance and longer run time than the 6/8v Trojan T875 pack. Plus we lost 300 pounds of dead weight. Reduced load = less watts needed. These 2 factors, more voltage and less load make the 72AH pack quite serviceable and its relatively affordable. Remember Amp hour capacity is fuel capacity. A more critical spec is maximum amperage draw. This is a battery spec, a limit where the pack's battery management system (BMS) shuts off the current draw to save the pack from being damaged. We have seen 100 maximum amp draw (MAD) packs shutdown on stock 'for golf' carts. And we have seen 200 MAD packs shut off big tire and aftermarket motor carts. The ECO battery has a MAD rating of 300 amps. This is my choice having reviewed hundreds of Alltrax monitor files for so many configurations. |
08-09-2022, 09:11 AM | #5 | |
Gone Wild
Join Date: May 2012
Location: Rio Verde, Az
Posts: 7,121
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Re: Are Ah needs the same?
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08-09-2022, 01:09 PM | #6 |
Gone Wild
Join Date: Jan 2013
Posts: 164
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Re: Are Ah needs the same?
Thanks guys. I guess my next question/concern is that I have an Alltrax controller running about 400-425 (set by you ScottyB several years ago), so the hills scare me a little with the BMS if I get into a hill and just floor it to the top. I like the idea of lithium, but also don't want to spend double and have to change the way everyone drives it. Do you re-profile your alltrax with the conversion, or leave them?
The biggest reason I asked is that after talking to our local dealer, they have only installed a handful of over 60 Ah set ups (at least in the conversions they are doing). That seems really low to me, but puts the price tag much closer to a FLA replacement, so appealing in that sense. I am still researching all of this, but want to make sure I am comparing apples to apples kind of thing. |
08-09-2022, 02:02 PM | #7 |
Gone Wild
Join Date: Mar 2016
Location: Sarasota, Florida
Posts: 387
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Re: Are Ah needs the same?
I just installed 105ah RoyPow in my club car with a scotty c54 kit, aka alltrax sr48500.....
I changed 1 parameter, that was the map from speed to torque. It certainly gave me oomph from a start and funny enough it added a few miles per hour to top speed as well. |
08-09-2022, 03:57 PM | #8 | |
Gone Wild
Join Date: Jan 2013
Location: Saint Petersburg, FL
Posts: 2,089
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Re: Are Ah needs the same?
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*Caveat! This is for my cart, your cart will be different! I changed the torque/throttle curve so it'd be less jarring. With that much less weight it wanted to accel a lot harder and I wanted more control. If I floor it I want accel, but if you press the pedal half way I don't want to have "yeeted my people off the cart" as my daughter would say. I played with the regen a lot to get it right where I wanted it. I think I have regen set to 84 or 86 amps max and the shunt set to 0 amps. This way it slows the cart as if you are mildly putting on the brakes then when it gets to a crawl it rolls. This puts energy back into the pack but doesn't just shunt the power when the motor's not spinning fast enough. It works out pretty well. I also set the controller to cut off at a different Low Voltage cutoff. The LV cutoff for lead acid was set at something like 28v or some such, crazy low. My DIY lithium pack maximum limits are 58.8v 100% charged to 42v fully discharged. I want my controller to stop the cart before the battery and when it's that discharged there isn't much left so I set the low voltage cutoff to 45.5v. Just for clarification I never charge to 58.8v for longevity but that's nothing to do with the controller. I didn't need to worry about the HV cutoff, where I live there are no hills so I can't regen and go over the battery max. So I just maxed out the HV cutoff. That's all done in the free software. I don't think I changed anything else. If you're worried about max current then you can reduce it to 350. My max battery amp setting is 360 and I've done wheelies at 304 amps (and 54v). I haven't seen anything higher than 304 amps. When you drop that much weight you don't need as many amps to move it. I changed it to not be so aggressive so wheelies don't happen so my real world max amp draw is probably closer to 270 amps now. If your drop-in replacement tops out at 52 or 51v or any number less than mine then the amps will increase to do the same work. Wheelies at 51v will require more amps than wheelies at 54v. As it stands now my neighbors new ICON cart with lead acid batteries and an AC drive out accelerates me for the first 10 feet then I whip past him. I could shift to a more aggressive torque curve and out accel the first 10 feet but I don't like the harshness. I did limit my top end to 24mph based on RPM so he will catch up after a while if there's a long enough stretch. I didn't like the handling of the lightened cart over 24/25mph. $0.02 |
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08-12-2022, 07:56 AM | #9 | |
Getting Wild
Join Date: Jun 2022
Location: Palm Beach County
Posts: 95
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Re: Are Ah needs the same?
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