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LTO BMS SOURCES?

salbers12

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Aug 30, 2021
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My project consists of a nominal 13.8 VDC X 750 AH battery. The configuration will be either 6-30 AH cells in series per battery paralleled into 750 AH OR 25- cells in parallel X 6 INTO 750 AH. I'm looking for manufacturers of BMS compatible for LTO cells. All recommendations will be appreciated.
 
You'll probably get better responses if you tell us what the application is ..... How much peak and sustained current you expect to draw.

As a side conversation, I'm interested to know why you chose LTO cells ... and where did you get them. You can message me if you don't want to junk up the thread.
I really like the LTO cells and may consider them for future projects.
 
Bob,

Thank you, thank you for your interest in my LTO project. I'm a retired airline pilot interested in RVs. I was shocked at the absolute garbage peddled for product in the RV industry - invariably 10lbs of shit crammed into a 7lb bag -totally unable to survive in real-world temperature extremes (It was 128 F in the desert outside Las Vegas a couple of weeks ago and Montana winters routinely produce cold snaps to -20 F). The RV industry's solution is to shut down the product when it cannot handle real-world temperatures so the owner loses the use of his investment for several months per year - ridiculous.

I decided to try for something better. My target from weather bureau data to handle 98% of temperature extremes in the Americas and Europe is -20 F to +130F. I've produced a shell with state-of-the-art insulation on a frame strong enough to handle the constant pounding of unimproved roads.

120V/30A AC and 13.8 VDC electrics start with as much battery capacity I can engineer into the available space, presently implemented with 150 Yinlong LTO prismatic 30AH cells. Perfect Switch has provided the BMS. Delagreen Power contracted for the balancers. Balancer prototypes were noisy but worked fine. But the entire order was bad and had to be returned. Right now my balancer selection is up for grabs. Delagreen will be offered the opportunity to fix their product while I consider alternatives. Very few companies make LTO balancers. I've looked at the Orion but it cannot handle my configuration (https://www.orionbms.com/). I'm presently evaluating the 123BMS https://shop.gwl.eu/_d7508.html#tab4). All components have passed testing in commercial labs because I could not reach the specified temperatures any other way. Your experience is respected and your input on my project would be most appreciated, particularly any balancer recommendations.

Stephen
 
Have you looked at what the audio market is using? I think they are the largest users of LTO cells ..... in the US anyway.
I think many of them are just using active balancers and not using a BMS .... These cells are very forgiving, but I would still want a BMS.
I would refer you to @Craig .... but I'm not sure he even frequents this forum any more. He was using LTO cells in a remote cabin and was also selling them pre-tested on Ebay. I don't know who else on here might be knowledgeable about LTO.

Depending on how much peak current you are planning to have, you might consider one of the contactor type BMS. Chargery is one of them, but I wouldn't buy one of them right now til they get their new product to market and vetted.

I would start by searching on here for LTO ... by Craig and go from there.
 
Bob,

We are hot on the trail of LTO BMS alternatives. Watching your latest YouTube videos has inspired me to seek your advice on a related matter. No one has done this before in an RV. I'd like to brainstorm your opinion of what it would take to configure our 25P6S battery pack so that it could be charged from EV charging stations? Appreciatively, Stephen
 
Bob,

We are hot on the trail of LTO BMS alternatives. Watching your latest YouTube videos has inspired me to seek your advice on a related matter. No one has done this before in an RV. I'd like to brainstorm your opinion of what it would take to configure our 25P6S battery pack so that it could be charged from EV charging stations? Appreciatively, Stephen
Sorry, but if you are addressing me .... I don't do YouTube videos ..... so that isn't me.
Sorry again, but I don't know anything about EV charging stations.
 
Batrium BMS will do what you need.

I’d be interested to see your numbers, i only know a couple of LTO RV systems, they were more expensive than a LiFePO4 / RC A/C combination. (without the benefit of the Aircon).

The key to a cost effective RV system is maximising available PV.
 
I've been going over this in my head, and I don't see a need for a true bms for an lto pack. I think with a robust active balancer you should be able to get by with direct wiring them in most situations. assuming inverter usage, pretty much every inverter on the market will have low and high voltage cut outs, same with chargers, if low temp cutoff is a non issue with this chemistry as long as you use a cell level active balancer you probably don't need a true bms.
 
@salbers12 did you find a BMS you like?
I'm considering my options now for a BMS for an LTO build. 12s6p with Toshiba cells likely. Maybe 12s3p.

@wild01 I would love to get away without a BMS. i wonder why others are adamant that they should be used if the charge contoller and inverter voltage set points are adequate?
 
@salbers12 did you find a BMS you like?
I'm considering my options now for a BMS for an LTO build. 12s6p with Toshiba cells likely. Maybe 12s3p.

@wild01 I would love to get away without a BMS. i wonder why others are adamant that they should be used if the charge contoller and inverter voltage set points are adequate?
With a cell equalizer , all the set points are proper boundaries .

Also, " I spent more money , so I'm right" mentality.
 
I'm no LTO expert, my post was more musings based on data sheets than personal experience. (Placed here to be peer reviewed/torn apart if I was overlooking something)On my lifepo4 packs I really like the 5a heltec cascading capacitor balancer. However if you go this route leave it hooked up and on all the time. I don't think they limit inrush current, so it's very bad for them to be disconnected/reconnected. I've noticed on mine they get hot and smell like overworked electronics if they are.
 
I'm no LTO expert, my post was more musings based on data sheets than personal experience. (Placed here to be peer reviewed/torn apart if I was overlooking something)On my lifepo4 packs I really like the 5a heltec cascading capacitor balancer. However if you go this route leave it hooked up and on all the time. I don't think they limit inrush current, so it's very bad for them to be disconnected/reconnected. I've noticed on mine they get hot and smell like overworked electronics if they are.
I was looking at those and they do have ones for LTOs, so think I'll try it out. Thanks!
 
I use a capacitor equalizer for anything under 40AH and use a Qemm for over 40AH with trickle charger system
Ah I see. What Qemm do you use? Got a good source to buy? Thanks!
 
Ah I see. What Qemm do you use? Got a good source to buy? Thanks!
Sorry I am spelling dysfunctional ( I thank the spell check gods)

The brand is Qnbbm , They work very well , but use a lot of power . It will drain a 30ah battery down in 30-45 days if it is not a daily driver .
The unit uses a transformer design to work on all the cells at the same time .You need to shop around for the best deal

https://www.aliexpress.com/item/100...;129.23;-1;-1@salePrice;USD;search-mainSearch

Jimjr
 
Bob,

Thank you, thank you for your interest in my LTO project. I'm a retired airline pilot interested in RVs. I was shocked at the absolute garbage peddled for product in the RV industry - invariably 10lbs of shit crammed into a 7lb bag -totally unable to survive in real-world temperature extremes (It was 128 F in the desert outside Las Vegas a couple of weeks ago and Montana winters routinely produce cold snaps to -20 F). The RV industry's solution is to shut down the product when it cannot handle real-world temperatures so the owner loses the use of his investment for several months per year - ridiculous.

I decided to try for something better. My target from weather bureau data to handle 98% of temperature extremes in the Americas and Europe is -20 F to +130F. I've produced a shell with state-of-the-art insulation on a frame strong enough to handle the constant pounding of unimproved roads.

120V/30A AC and 13.8 VDC electrics start with as much battery capacity I can engineer into the available space, presently implemented with 150 Yinlong LTO prismatic 30AH cells. Perfect Switch has provided the BMS. Delagreen Power contracted for the balancers. Balancer prototypes were noisy but worked fine. But the entire order was bad and had to be returned. Right now my balancer selection is up for grabs. Delagreen will be offered the opportunity to fix their product while I consider alternatives. Very few companies make LTO balancers. I've looked at the Orion but it cannot handle my configuration (https://www.orionbms.com/). I'm presently evaluating the 123BMS https://shop.gwl.eu/_d7508.html#tab4). All components have passed testing in commercial labs because I could not reach the specified temperatures any other way. Your experience is respected and your input on my project would be most appreciated, particularly any balancer recommendations.

Stephen
May I ask what insulation you used for your project?
 
JK BMS supports LTO as well.
Darn, I was just ordering the JK BMS and realized it only supports 14s or higher for LTOs according to the documentation. Why is that? Can't I just leave some wires unattached, or is it a voltage issue? Anyone know of a workaround for it to work with 12s?
 
Darn, I was just ordering the JK BMS and realized it only supports 14s or higher for LTOs according to the documentation. Why is that? Can't I just leave some wires unattached, or is it a voltage issue? Anyone know of a workaround for it to work with 12s?

Because LTO sits at a lower voltage. The discharge graph looks like this:

lto.jpg
The BMS needs a certain minimum voltage, and with LTO cells you can go below that in a 12s configuration. You could use a boost converter - similarly to what people do to make this BMS work with a 4S LiFePO4.
 
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