Electric forklift replace battery with EV battery

[Bill D]

The Edxison batteris use a simple charger and last forever. They have have low energy density so weigh a lot more then lead acid.
Bill D

 

[tomjelly]

And still nobody here has tried to power an electric forklift with a welder yet. I'm waiting.

 

[crickets]

And still nobody here has tried to power an electric forklift with a welder yet. I'm waiting.

Skip the welder, go straight to the melter. One of the Lithium Triathlon forklift batteries I came across had capacity of 416Ah, which means it could easily peak to 4160A at 57V... that is if you were to bypass the BMS

 

[john.k]

20c/kg = 8-10c/lb

 

[BT Fabrication]

well not really efficent, a car EV battery runs about 272VDC, so won't work with a 48V system without some major electronics. As DC won't work with any sort of transformer to step it down, only means a really expensive inverter that can handle that high of voltage and not just kill anyone that charges the battery. thats why the motors are all 3 phase, i believe it runs off 244V

 

[markp]

Theres a Tesla hacker out here in the Bay Area. The guy you go to to unlock your Tesla for drag racing or get "special" software written and installed. He has an order picker with Tesla battery modules installed, 48v. Yale I think. He made his own battery management system for it. I was at his shop and saw him load some stuff with it and he said it works ok, gets about 4 hrs on a charge. With the straddle legs its not so important to have a big heavy battery. He also has an entire Tesla car battery bolted to the wall connected to solar panels!

 

[crickets]

well not really efficent, a car EV battery runs about 272VDC, so won't work with a 48V system without some major electronics. As DC won't work with any sort of transformer to step it down, only means a really expensive inverter that can handle that high of voltage and not just kill anyone that charges the battery. thats why the motors are all 3 phase, i believe it runs off 244V

Most current street-legal EVs have either 400 or 800 volt batteries. EV battery in this context is not to directly power the forklift, but to serve as a donor of cheap battery cells. One doesn't even need to buy the whole battery and take it apart - there are many online vendors, including on Ebay, selling individual modules from a variety of EVs. No major electronics is required. Also you can't step-down DC with a transformer, need a DC-DC (buck) converter instead.

 

[dalmatiangirl61]

OP has not been back, so either he is absorbing knowledge, he got 4 new 12v LA batteries and has it running, or the lift has been scrapped.

 

[john.k]

I used to see some really nice electric forklifts sell for scrap price when the battery needed replacement ......with the conventional 2 ton size sit on machines prices would fluctuate from around $7000 with a new battery to just above scrap when the battery was all swelled and multiple cells bridged out.

 

[BT Fabrication]

Most current street-legal EVs have either 400 or 800 volt batteries. EV battery in this context is not to directly power the forklift, but to serve as a donor of cheap battery cells. One doesn't even need to buy the whole battery and take it apart - there are many online vendors, including on Ebay, selling individual modules from a variety of EVs. No major electronics is required. Also you can't step-down DC with a transformer, need a DC-DC (buck) converter instead.

I work in a factory that builds them in qc.
They are no where near 400v
They are in the 240v to 280V range.
Ask me how i know.
Ev toyotas run on 247V
Hybrids are 272V

 

[crickets]

I work in a factory that builds them in qc.
They are no where near 400v
They are in the 240v to 280V range.
Ask me how i know.
Ev toyotas run on 247V
Hybrids are 272V

You're probably talking about Hybrids, because Toyota hasn't produced any EVs until recently and likely doesn't have many on the road if any. Here is a short list of mass-produced EVs and their voltages:

Nissan Leaf - 364.8V
Tesla Model S - 351.36V
Chevy Bolt - 344V
Audi E-Tron - 396V
BMW i3 - 360V
Polestar 2 - 400V
Kia Niro - 356V

Porsche Taycan - 723V
Hyundai Ioniq 5 - 523V / 653V / 697V
Audi E-Tron GT - 723V

Those are nominal voltages (50% of the charge). When we say 400V or 800V we refer to the approximate charging voltage in order to get a full charge. For example Nissan Leaf would be at 403.2V fully charged. Also there is a minor discrepancy due to how various manufacturers report nominal cell voltage of their corresponding chemistries. For example Tesla uses 3.66V for NCA cells, but Leaf NMC cells (produced by NEC I believe) are reported at 3.8V nominal.


Edit:

It appears bZ4X is the first (modern) fully electric vehicle Toyota has released just last year. It has a 355V battery pack.

 

[johansen]

I work in a factory that builds them in qc.
They are no where near 400v
They are in the 240v to 280V range.
Ask me how i know.
Ev toyotas run on 247V
Hybrids are 272V

Some of them had voltage doublers in the battery pack and they ran 500+v to the motors.

The battery cell count is a trade off between statistics, insulation requirements and losses.

 

[markp]

The guy who had Tesla batteries in his 48 v order picker broke the batteries apart into 24 v sections. As I recall, he said they were older model S donor batteries.

 

[crickets]

The guy who had Tesla batteries in his 48 v order picker broke the batteries apart into 24 v sections. As I recall, he said they were older model S donor batteries.

Tesla modules have 6 cell groups in series, which makes them 21.96V (3.66V per cell) nominal. Two in series is then 43.92V, which may be too low for many 48V applications where undervoltage protection is provided. For comparison 48V FLA will have 50.8V fully charged, 45.6V fully discharged. For this reason 12s configuration is not ideal, and 14s is a better option: 58.8v - 51.8v - 39.2v.

 

[awizz13]

We did this to a reach truck recently - only use it a few moments per day and it was something like $5,000 for a new battery!

We got three 12v/2000ah batteries - like the ones in floor scrubber machines - and wired them in series.

Added an on-board 18 amp golf cart charger and we could not be happier.

No issues with filling the water either! Just plug it into any wall outlet where ever it happens to be!

We added a metal box filled with steel punch slugs to approximate the total weight of the old battery. (part of the counter balance metrics)

 

[hanermo]

Lots of good stuff in this thread ..
especially the EV cars voltages for various brands.

In reality, any battery of sufficient capacity will power any motive source, like a forklift, or a car, and any voltage needs are easily done by a dc-dc converter.

So far, tsla, only, has a superior power electronics module for drive use - essentially a 3-phase vfd of very high efficiency.
Porsche taycan 88 m/kWh, Tsla S 120 m/kWh, tsla 50% better.

Obviously, the porsche power electronics+motive train will get better, over time, and more/less the same level as the tsla solution.
This all takes time.
And engineering, and learning from the first units that had x problems.

It´s very difficult to make a set of 1400 peak amp - 400 V - tesla motive motor - VFD electronics - that is is very reliable AND Very efficient.
Small, cheap to produce.

Tsla did at least 14 iterations on the VFD -- and exactly zero current global providers have anything similar.
Of course, over time, magma, bosch, similar, will learn to make similar stuff-

 

[Bill D]

What about bumper car wiring. Steel floor plate with metal ceiling as conductors. for in door use only.
Bill D

 

[crickets]

Lots of good stuff in this thread ..
especially the EV cars voltages for various brands.

In reality, any battery of sufficient capacity will power any motive source, like a forklift, or a car, and any voltage needs are easily done by a dc-dc converter.

Yeah, when your current is under 30A or so. Take a look at DC-DC converters rated for 400A, you are in for a surprise.

 

[hanermo]

Yeah, right.
The tsla 7-in-1 power module is under 20 kg in mass, under 500$ in costs, does 1700 amps at 400V, and delivers cabin heating as a controllable byproduct.
And battery heating.
There are breakdowns, from sandy munro and others, and component costs are well known.

The tesla module is cheap because it is very efficient - thus not losing lots of power in heat -- thus not requiring lots of cooling and heat sinks and extra power components.
It re-circulates current losses very well.
By about 2020 tsla had built at least 13 versions, shipping, using 203 igbts. before their own power modules, currently shipping.

Yeah, when your current is under 30A or so. Take a look at DC-DC converters rated for 400A, you are in for a surprise.

 

[crickets]

Yeah, right.
The tsla 7-in-1 power module is under 20 kg in mass, under 500$ in costs, does 1700 amps at 400V, and delivers cabin heating as a controllable byproduct.
And battery heating.
There are breakdowns, from sandy munro and others, and component costs are well known.

The tesla module is cheap because it is very efficient - thus not losing lots of power in heat -- thus not requiring lots of cooling and heat sinks and extra power components.
It re-circulates current losses very well.
By about 2020 tsla had built at least 13 versions, shipping, using 203 igbts. before their own power modules, currently shipping.

A couple of things... First, this is not a thread about Tesla's design or manufacturing innovations. Second, most modern industrial motor controllers are quite compact even though they're relatively highly rated. For example, you can take a look at Sevcon Gen4 Size 6 controllers which are rated for 650A (11lb package).
Finally, here is an example of a DC-DC converter one would have to use to run a forklift from a battery of the "wrong" voltage:

https://www.zekalabs.com/products/isolated-power-converters/dc-dc-isolated-converter-15kw-400a

(40lb package, couldn't find the price, but likely many thousands)