Here at Battle Born Batteries, we stand behind the products that we build. Backed by a 10-year warranty, our batteries are also internally protected by a battery management system (BMS). This latest installment is all about the internal BMS for our batteries and their capabilities.
What is a battery management system and why do our batteries have it?
As the “brain” of our battery, this internal device protects the cells around it from different damaging scenarios. High and low voltages and temperature extremes can hurt your system, and this device can sense a short and shut it off. At the top of each charge cycle, it reduces the charge rate in cells that have been topped off first to maintain the battery’s overall quality and efficiency of the cell pack.
Our team does not recommend purchasing a battery unless it has an internal battery management system because it can make all the difference in protecting your battery from being damaged.
Our internal battery management system is rated for three different levels.
- 100 amps continuous (1200 watts at 12 volts) – this means you can pull 100 amps out of the battery when you need it until the capacity is all used up.
- 200 amps for 30 seconds (2400 watts at 12 volts) – if your device has a surge, an individual battery can deliver 2,400 watts for 30 seconds.
- ½ second surge up to the max capacity of the battery. If you have a high moment over 200 amps, the battery will handle this for ½ second.
One hundred (100) amps continuous, or 1,200 watts at 12 volts can pull all amps out of the battery when you need it until the capacity has been depleted. Our battery management system will not allow a current that exceeds 100 amps for more than 30 seconds and cuts off any surge over 200 amps after half a second.
Please note that when you have two batteries in parallel, the surge levels are doubled.
Can the internal battery management system regulate amperage from an alternator?
When it comes to regulating amperage from an alternator, the BMS does not have the capability to do that. If you’re in a situation where you only have one or two batteries, we do not recommend you charge a battery more than 50% of your whole battery bank.
If you only have two batteries in your van, and you’re running a 225 amp alternator, you can potentially pump 225 amps into a battery bank that can’t be charged more than 100 amps. Regulation of those amps must go through a battery-to-battery charger, which we sell from Victron.
It’s important to regulate this current in order to charge the battery properly without shortening the lifespan of your Battle Born Batteries.
Does the internal battery management system control charging?
Our BMS does not limit the charging current, and our team always recommends a 50 amp charge rate for a 100 amp hour battery. You can charge at a higher charge rate of 100 amps in emergency situations where it’s necessary, but we do not recommend it, especially for long periods of time. With 200 amps for 30 seconds, the device will ensure that it can deliver 2,400 watts for 30 seconds.
Does your battery management system cut off the charge if the voltage goes above 14.6 V?
In this video, our CEO Denis explains how, in order to preserve your battery and your rig, the internal BMS will prevent a charging current if it experiences a voltage increase above 14.6 volts. It’ll continue to allow discharging and it doesn’t happen right away at 14.6 volts. The BMS measures the voltage of each individual cell and if the highest cell exceeds the threshold voltage, it will prevent charging.
We’d like to note that sometimes this process can occur at 15 volts or as low as 14.4 volts.
If the battery cells are imbalanced, they can be rebalanced again. If you happen to see the battery cuts off charging below 14.4 volts, that’s just an indication of a minor imbalance. The battery is still functional and it’s no cause for concern. If the battery spikes to 15 volts, then the level of imbalance is very high. Our team stresses the importance of aiming for that sweet spot of 14.2–14.6 charging voltage because those numbers are guaranteed to avoid high voltage disconnect.
High voltage disconnect happens when a cell experiences a high amount of voltage. The battery will prevent a charging current from happening. Cells can no longer charge, and excess voltage puts them out of operational specs. The BMS, when in high voltage disconnect mode, cannot disconnect from the system. Even though the battery won’t take a charge current, it will always allow a discharge current. As soon as you try to draw a current out of the battery in high voltage disconnect, it will allow that current to power your load.
How can our batteries and their internal battery management system handle high current disconnects?
The battery will disconnect during a moment of high currents in the system and try to establish reconnection again after 5 seconds. It lets the user know that it’s approaching the threshold that is specially designed for. If this happens often, our team suggests looking into expanding your battery bank’s capability. Our batteries also have a half–second threshold to allow for a crank of an engine or generator. If this happens, our batteries will disconnect and restart to protect you and the rest of your system. These high current events are not short circuits. The batteries will disconnect, but not reconnect after 5 seconds if they were to experience a short circuit.
Please note that if you have our batteries in your system and a 4 kilowatt or greater inverter, you will need a Current Surge Limiter. The soft–start avoids the high-current shutoff inherent to the internal BMS.
We’ve covered a wide range of topics throughout our FAQ series, which can be found here, and offer plenty of video resources on our website. Check out our YouTube channel for additional videos and if you’ve got more questions, the Battle Born sales and tech team is always happy to help. You can give them a call at 855-292-2831 or send an email to [email protected].
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