All lithium batteries should have a Battery Management System (B.M.S.)

The information I am providing is based on over 10 years of development of Lithium batteries for the racing industry. But don't just take my word, do your own research, simply Google "Do lithium batteries need a BMS?"

A Battery Management System (BMS) performs several functions, with one of the most important being to disconnect the battery if a cell's voltage gets too low and to stop charging when a cell reaches its maximum charge. When a lithium battery cell discharges below a certain voltage (approximately 2.0V for LifePo4), it may begin to damage the cell by creating small short circuits, known as dendrites, between the anode and cathode. A damaged cell will continue to deteriorate until it fully shorts out. When a cell shorts completely, the battery's voltage decreases, for example, from 12 volts to 9 volts. However, the charger remains set for 12 volts, leading to overcharging of the good cells and causing the shorted cell to heat up progressively during continued charging. The charger does not shut off because the battery cannot reach 12 volts. This situation can result in thermal runaway, where the battery cells experience uncontrollable self-heating and subsequent degradation, making it difficult to halt the reaction.

The BMS prevents these bad things from happening!

Cell balancers, often built into the BMS but sometimes separate, help equalize peak voltage in lithium batteries by bleeding off excess charge as heat. While they can handle about 500mA of current, they may be overwhelmed with chargers outputting 10-25 Amps. Balancers are passive devices that cannot stop cells from being overcharged or over-drained; only a BMS can do that.

Cell Balancers do NOT replace a BMS or provide any protection from Thermal Runaway!

Do batteries with a BMS fail more often due to complexity? No, they are more complex, but they help extend battery life and ensure proper functioning. You are more likely to damage a cell in a battery without a BMS, then have a BMS failure.

Could the BMS fail? Sure, nothing is perfect. As a racer myself, I would hate to lose because something breaks. However, consider this: Would you prefer to lose a round or risk burning down to your car, trailer, shop, or home?

Altronics Powerlite batteries have not had a single BMS failure in over 4 years!

No matter what brand of lithium battery you decide to purchase, make sure it has a BMS!

Please watch the short video below on what goes into the Powerlite Lithium battery. Feel free to contact us if you have any questions.

https://www.youtube.com/watch?v=X6m8as86Pf0

This message has been edited. Last edited by: Altronics,

This won’t be popular but shouldn’t these batteries ( lithium) be in a containment system
Like a steel box?

quote:

Originally posted by BP758:
This won’t be popular but shouldn’t these batteries ( lithium) be in a containment system
Like a steel box?

I suppose if you purchase one without a BMS!

my batteries have the bms...has saved me a few times

No different than LiPo RC batteries. I've seen entire houses get burned to the ground because people didn't properly store something as simple as a small 3 Cell battery.

I'm assuming your BMS monitors individual cell voltage? If so is it capable of cutting power to the car if a cell gets over discharged? Can the user adjust the min voltage for discharge protection?

quote:

Originally posted by 1.Slow_fivE.0:
No different than LiPo RC batteries. I've seen entire houses get burned to the ground because people didn't properly store something as simple as a small 3 Cell battery.

I'm assuming your BMS monitors individual cell voltage? If so is it capable of cutting power to the car if a cell gets over discharged? Can the user adjust the min voltage for discharge protection?

Yes, the Powerlite BMS will cut power when the battery is discharged past a programmed voltage. This is not user configurable. The voltage that we cut off battery is at an absolute minimum. The battery has to be below this set point for a specific amount of time. We obviously do not want a battery to turn off during a run, so we try to push it as far as possible!

Note: The 'Turn off voltage" is at a point where the battery would have very little power left. It would be unlikely in a drag race scenario that you would have enough power left in a "Low Battery" scenario to still crank over and start the engine, but not have enough left to complete the run. This will more likely come into play when the racer leaves the power on accidentally after a race while storing the car.