48v Lithium 100ah battery

[DaveTM]

Originally Posted by NoleFan4Ever

Like they said, but the cost of 4x12 lithiums is astronomical. Get you a good dependable lithium pack from a trusted source. I will share the one I use and have successfully several times https://hi-powerbatteries.com/produc...arger-package/. These packs give you the BMS size and all specifications so you can look and see how they compare to your needs. I have used the 48v (56.4v fully charged) 100 a/h and the 120 a/h. The 120 a/h can be driven cross country.

I do not like these as much as my Leaf Pack, but they are working out greatly in my fathers series and the boys sepex CC's.

Yeah....I'm agreeing with Pat911 on this. I dunno what a "bigger BMS" actually means....unless the BMS is rated for allowing more amps in continuous or peak time frames.

When I looked at the aforementioned website, one of the battery packs stated "225 amp bms built in. 800 amps peak"....when what I think they mean is "225amp continuous and 800amps peak." However what they don't say is how long (usually seconds) will the BMS allow 800amp peak?

OTOH, I know my cart has never demanded nor needed 800amps. The most was close to 400amps and after obtaining that reading I've set my controller to only allow (IIRC) 320amps. The lower setting has not had a noticeable effect in cart performance.

The "peak" amps allowed is important as you may want to know how many amps your cart draws in area's (hills\mountains) you drive....and how long your cart demand's those "peak" amps. Now, it may state the peak amps at 800....but I think what's important is once your cart draws over the 225 continuous amp allowance (if it does) how long will the BMS allow the draw of the higher amps...the amps over 225.....before it shuts down the packs power.

[Kolassus]

You guys are awesome. Thank you. This forum has made my golf cart modding hobby fun, educational, and practical. I think you have all answered my questions thoroughly. I guess my final question would be with my current setup, if my options are 6 brand new Trojan 875 batteries or a single eco 48v lithium battery, will I notice a difference between the two performance wise? From the sounds of it, the lithium will last much longer, but will the cart perform any different?

[CP241]

Yes. The cart will perform better due to a higher, more stable voltage and approx 300 +/- pounds less weight. Torque, acceleration, and top speed will all be slightly better.

You’ll still probably have to limit max amp draw in your alltrax but with lithium that’s usually barely noticeable, if noticeable at all.

Add into that the other benefits of lithium, primarily no corrosion to worry about, no watering to deal with, and you don’t have to charge it every-single-time you use the cart to maintain the battery health. Just charge as you need to, whenever the cart needs it and drive.

[NoleFan4Ever]

Originally Posted by Pat911

That's not quite how it works. The BMS should be sized to protect the battery cells. You cannot simply put in a larger BMS if the cells are not rated for the increased current. The BMS is the limiting factor because, amongst other things, that's it's job, to limit the current to protect the cells. Your Leaf cells are another story and a golf cart will never demand more current than those cells can easily supply.

Cheers
Pat.

I think you misinterpreted my information. I very well know how the BMS works and a lithium pack as I work and tune them very often. The problem with the referenced pack was it had a small BMS (for a solar unit back-up) that could not take the surge amps of the cart. The supplier realized that when I sent him the data and he forwarded to he the manufacturer for their review and they agreed with an engineering response and shipped me a new (larger) BMS. It has been well over a year and it works great and will continue to do so. Thus my original point of know your manufacturer as me and Sergio ran through this two years ago with several members where they bought ebay (chinese) packs and the BMS's were not capable of golf cart surge amps and would continuously trip out. They did work fine for the smaller equipment they were being used on.

[Pat911]

OK, so what you're implying is that the BMS was initially undersized for the cells it was protecting. If that was the case then yes, a larger (read higher current rated) BMS is a solution.

[jasonojordan]

Originally Posted by Pat911

OK, so what you're implying is that the BMS was initially undersized for the cells it was protecting. If that was the case then yes, a larger (read higher current rated) BMS is a solution.

Not likely undersized but built for a different application. No sense in throwing in a more expensive BMS that handles amp draws that will never be seen in the intended application even if the cells can handle it.

Either way looks like all the information is out there in the open now for the OP.

[8-point]

Originally Posted by Kolassus

You guys are awesome. Thank you. This forum has made my golf cart modding hobby fun, educational, and practical. I think you have all answered my questions thoroughly. I guess my final question would be with my current setup, if my options are 6 brand new Trojan 875 batteries or a single eco 48v lithium battery, will I notice a difference between the two performance wise? From the sounds of it, the lithium will last much longer, but will the cart perform any different?

I totally agree, all these guys here are super smart, awesome and very helpful obviously including CP241 who was also spot on with the lithium benefits description. Go get you that Eco Lithium Battery and you won’t regret anything.

Mike

[DaveTM]

Originally Posted by NoleFan4Ever

I think you misinterpreted my information. I very well know how the BMS works and a lithium pack as I work and tune them very often. The problem with the referenced pack was it had a small BMS (for a solar unit back-up) that could not take the surge amps of the cart. The supplier realized that when I sent him the data and he forwarded to he the manufacturer for their review and they agreed with an engineering response and shipped me a new (larger) BMS. It has been well over a year and it works great and will continue to do so. Thus my original point of know your manufacturer as me and Sergio ran through this two years ago with several members where they bought ebay (chinese) packs and the BMS's were not capable of golf cart surge amps and would continuously trip out. They did work fine for the smaller equipment they were being used on.

I likely did misinterpreted your post. My BMS is designed so that the "heavy current draw" does not go through the BMS at all. My HV (High Voltage) and LV (Low Voltage) relays cut the charge or power draw should a given cell reach whatever voltage I have it set to.

Hence my comment.

However, before I would buy a pack from the link you posted I would need clarification of what the continuous amp draw is, and how many seconds the BMS allows a "spike current draw" above the 225amp mark.

[NoleFan4Ever]

Yes everyone, the original pack referenced was under in regards to the BMS as even though it was advertised for most everything, including a golf cart, they had not had one used in that application till we came along. It was obvious when I opened it and found it, so I did the calculations and sent the report to them. After their engineering agreed with it and the needs of the cart, they supplied me a replacement (larger BMS) and once installed, there has never been another problem. They also changed the BMS's going forward to fully accommodate a golf cart need.

The pre-packeaged lithiums today can be great as compared to us having to build our own a few years ago (although I still prefer the Leaf packs), but you have to be sure of the spec's as that will be critical to the success of the replacement. One pack may work fine on a solar back up, but not a cart, if it was not designed to handle the characteristics of a golf cart. In this case the pack was enough, but the BMS was too small and an "engineering approved" replacement took care of it.

Now Kolassus, you have plenty of information to make an informed decision. Good Luck!

[Pat911]

It's good to know the back story and thanks for clarifying. I just wanted to make it clear to everyone that you just can't upgrade the BMS without making sure the cells can handle the increased current first.