lTO forklift battery repurposed for expedition camper

[Kevox]

I changed plans from using the 32 CATL LIFEP04 cells I bought in the group buy fiasco (now to be used at my house instead). I've been buying a lot of stuff on Ebay and Alieexpress using an app called social good which gives you 50% and 100% back in crypo for shopping through the app on those site. I bought a Voltabox 426AH 48V lithium LTO battery on Ebay for $7000. It was manufactured in late 2019 but never put in service. The seller has more available. Once I redeem the crypto after 60 days (approval time), I consider my net cost to be around $4000.
The battery weighed 1800 pounds as it is a drop in replacement for lead acid and therefore had to have a lot of ballast to match the LA weight. I hauled it home 430 miles from Tempe, AZ to Death Valley and rednecked it it out of the SUV.
I then took it apart in my driveway, pulled all the cells out and the cells only weighed 606 lbs. All the rest was ballast and the heavy duty steel box. The individual modules are 25.2V and 53AH. The quality looks fantastic with all hardware insulated and stout. The included display read 55% charged.

 

[Bob B]

That's an amazing find ... Have you capacity tested any of them yet?

 

[Kevox]

That's an amazing find ... Have you capacity tested any of them yet?

No, once I figure out the BMS wiring, I'm going to connect it to my All-in=One and my PV array and test the capacity through trial and terror...

 

[koppted]

No, once I figure out the BMS wiring, I'm going to connect it to my All-in=One and my PV array and test the capacity through trial and terror...

Any update on this? I'm attracted to LTO because of the low temp and discharge/overcharge tolerance.

 

[Kevox]

I have not had time to work on it. The bms it came with shut down when I charged and discharged it at the same time. I may not be able to use the bms...

 

[koppted]

I have not had time to work on it. The bms it came with shut down when I charged and discharged it at the same time. I may not be able to use the bms...

That absolutely sucks bro. Sorry to hear that. Have you tried contacting the maker tell them your use case, see if they'll help you out?

 

[Kevox]

I put the battery back together today for further testing. I will try to contact Voltabox but I think their American branch may be closed down. I figure each module must have 11 cells in series to make 25 volts. My guess is that each module has it's own BMS that is tied together with the other module BMS.s The BMS cable has 4 wires going in to a connector and another 4 wires coming out of a connector to the next module, I have 53 volts present at the input to the BMS. The handheld display shows the voltage and an error code which I am sure is from when I tried to charge it while also discharging it. If the company won't communicate with me (understandable if so), I will have to somehow trace the circuit board and prevent it from shutting down on simultaneous charging/discharging...
Should be interesting. I installed my Lifep04 set in my camper so these will be going to my house in Baja. It is currently powered by a generator for about 16 hours a day. I may be able to actually run it off that if I can clear the error since the generator can power the loads when it is running.

 

[chriscappuccio]

these look like lithium ion, not LTO ???

 

[PeSCaLo]

I put the battery back together today for further testing. I will try to contact Voltabox but I think their American branch may be closed down. I figure each module must have 11 cells in series to make 25 volts. My guess is that each module has it's own BMS that is tied together with the other module BMS.s The BMS cable has 4 wires going in to a connector and another 4 wires coming out of a connector to the next module, I have 53 volts present at the input to the BMS. The handheld display shows the voltage and an error code which I am sure is from when I tried to charge it while also discharging it. If the company won't communicate with me (understandable if so), I will have to somehow trace the circuit board and prevent it from shutting down on simultaneous charging/discharging...
Should be interesting. I installed my Lifep04 set in my camper so these will be going to my house in Baja. It is currently powered by a generator for about 16 hours a day. I may be able to actually run it off that if I can clear the error since the generator can power the loads when it is running.

Any updates

 

[chriscappuccio]

is it this battery?

 

[chriscappuccio]

TC5207-16 https://www.triathlon-batterien.de/

 

[Kevox]

• Discharging temperature range: -28 °C to +50 °C / -18 °F to +122 °F
• Charging temperature range: -28 °C to +50 °C / -18 °F to +122 °F

From your link...
I was able to charge and discharge simultaneously but only by bypassing the bms. heading to Baja Manama so I haven't had more time to play with them.

 

[chriscappuccio]

https://www.still.de/fileadmin/de/Microsites/Li-Ion_Technology/Batterietestzertifikate/Triathlon_2019_12_09_UN38.3_Testsummary.pdf

 

[chriscappuccio]

I got from the same seller. If anyone wants to pick some up I'll have them in Oregon. Maybe bus bars to each TC5207-16 is fine (no main BMS)??

 

[chriscappuccio]

I'm trying to get these guys to give up some info: https://www.triathlon-batteries.com/contact/

 

[chriscappuccio]

So the chemistry is NMC. The battery modules each have a control board that is connected to the Central Control Unit (main BMS) on the top. The CCU powers the module control boards. Without this powered connection, the modules have no BMS functionality at all. As you experienced, simultaneous charging and discharging is blocked as a safety mechanism for the forklift application. I asked if they can provide a CCU image that allows simultaneous charging and discharging, which they haven't replied to yet. Maybe foxBMS / Nuvation Low-Voltage BMS would work here.

 

[ajw8106507165]

Any luck with these?

 

[ajw8106507165]

Just received 8 of them I want to use in a 48v golf cart.

 

[chriscappuccio]

My first thought is to put all charging - solar and generator - in front of the BMS and put inverter(only) behind the BMS. That way, no fuss, no BMS swap, and hopefully I can get the full utility of the batteries.

 

[ajw8106507165]

Having issues with finding a charger that can support the batteries. Any suggestions?

 

[chriscappuccio]

Do you have the total forklift battery with the BMS?

 

[ajw8106507165]

I do have 3 total batteries with the bms.

 

[koppted]

So the chemistry is NMC. The battery modules each have a control board that is connected to the Central Control Unit (main BMS) on the top. The CCU powers the module control boards. Without this powered connection, the modules have no BMS functionality at all. As you experienced, simultaneous charging and discharging is blocked as a safety mechanism for the forklift application. I asked if they can provide a CCU image that allows simultaneous charging and discharging, which they haven't replied to yet. Maybe foxBMS / Nuvation Low-Voltage BMS would work here.

Can someone confirm whether or not NMC's have a thermal runaway issue, or at least more prone to it than LifePo4 and Toshiba's LTO's?

 

[chriscappuccio]

NMC has higher energy density and is more reactive to failures than LiFePO4 or LTO according to the common lore, and videos of people driving knives though batteries. i'd imagine these things are engineered well enough to survive in a forklift, as long as they aren't overcharged.

 

[curiouscarbon]

Can someone confirm whether or not NMC's have a thermal runaway issue, or at least more prone to it than LifePo4 and Toshiba's LTO's?

NMC chemistry has notably higher self heating property with relation to cell material temperature, as compared to LiFePO4 and LTO chemistry.

for NMC the heating amount per ampere goes up much more per degree temperature of cell material than LFP/LTO

Safety of Lithium-Ion batteries

Safety of Lithium-Ion batteries - PowerTech Systems

www.powertechsystems.eu

LTO is even less prone to self heating than LFP from what i understand