Wondering what to use to meet the ABYC requirement of an audible alarm before the BMS will disconnect your LiFePO4 batteries? Would a simple low voltage alarm suffice or do we have some new products out there to meet this requirement? Would be nice to have something more than a dumb threshold alarm...
Audible Alarm BMS?
- Thread starter markpj23
- Start date
hwy17
Anti-Solar Enthusiast
The Orion has an error signal output that you could relay to an alarm. But Orion is very complicated to implement and I'm not sure if this would always alarm before the shutdown, rather than alarm to tell you it has shut down.
DIYrich
Solar Wizard
You might be able to use this to read the status, and produce an audible alarm.
This is how you can use any LiFePo4 / Lithium battery single/multiple BMS(es) with any Inverter
Hi all too all DIY solar Fans, I'm new to the forum, but I've used it a lot and it has been a great help in setting up my DIY solar system with 8 banks of LiFePo4 batteries with Daly BMS's and SMA Sunny Boy and SMA Sunny Island inverters. So I've been running into the same problems as many here...
diysolarforum.com
Low voltage alarm would work in most cases, but would miss disconnect due to over current.
To truly alarm before the BMS disconnects requires a BMS that has that feature, and that will always only be on the more expensive BMS units. Prices will come down, but the cheap ones will never have that feature. There just isn't much demand for it as a it is a niche within a niche. I don't think is is going to mature any more, at least not in that direction. The direction it is going is with advanced CANBUS communications (expensive) for detailed monitoring, remote monitoring, etc.
I question the reasoning of the feature, as if a disconnect is to happen because of an overcurrent situation you damn sure need to disconnect right away and not wait for some alarm. Total battery voltage can easily enough be monitored with a Victron BMV and that is perfectly adequate for almost any situation. The individual cells should never go out of balance, as the BMS/balancer should prevent that. Most professionals seem to only recommend that you have a BMS that lets you monitor it's status via Bluetooth. AFIAK none of them have an alarm.
If you are concerned you can monitor cell balance with the midpoint monitoring feature of a Victron BMV. If the cells go out of balance, the 2 halves of the battery will be at different voltages, and you can alarm on that. But again, ABYC doesn't actually require any of that. It was in an early draft proposal (TE-13) but in the actual released standard (E-13) was removed.
ABYC Ratifies E-13, their first lithium battery standard
The ABYC has ratified standard E-13 for lithium ion batteries on boats. Let's take a look at the standard and what it means for boaters.
panbo.com
| NOTES | |
| 1. An alternative power source is recommended for critical systems (e.g., engine starting, propulsion, navigation lights, etc.) that may be affected if a BMS shuts down the battery. The alternative power source can be another lithium ion battery. | |
| 2. If a shutdown condition is approaching, a battery system should notify the operator with a visual and/or audible alarm before disconnecting the battery from the DC system. | |
| 3. BMS(s) may suddenly and unexpectedly disconnect a battery from loads and charging sour |
So it doesn't really sound like you are required to have that and/or not how people are thinking. Maybe when temp and/or voltage is reaching a certain programmable threshold it should alarm which would make sense. The JK Inverter BMS can do that but like the person states you're likely not going to hear it.
I already get a "Low Battery Voltage" warning from my chart plotters. I think the ABYC logic is that a LA battery will stay connected and provide power until it's completely flat vice the BMS cutofff. Not sure how that's a real-world difference except in the case of over-temp or high discharge cutoff scenarios. Your charging source - especially alternators - should be protected by design in a LIFEPO system anyway.
Seems like a business opportunity to me. These batteries are making big inroads in the marine and RV industry, and all could benefit from better monitoring & alarms available at the helm / dash.
Seems like a business opportunity to me. These batteries are making big inroads in the marine and RV industry, and all could benefit from better monitoring & alarms available at the helm / dash.
42OhmsPA
What's in a title?
My latest JBD smart BMS has a very loud annoying alarm that I can hear upstairs when voltage gets low.
Before E-13 was released the discussions I read were using examples like an electric powered boat that suddenly lost propulsion in tight quarters and that could cause a collision. It really isn't much different than lead acid. An overcurrent situation blows a fuse. Voltage drops below 11V and the inverter turns off. Many other electronics will also turn off with low voltage.
The biggest difference IMHO is that battery meters are VERY accurate with LFP. If it says you have 15% left, you know you have 15% left. That isn't possible with lead acid because of Peukert. So you look at the voltage, and if the voltage is 11.3V, with a 40A load, and the SOC says 40%, how much power is left? It sure isn't 40%. It's a guess, and you are more likely to lose power because of that than you are from and LFP BMS cutoff. In a practical example, I have had my LFP battery for 4 years, much of that full time living aboard. Never, not a single time, have I had a HVE cutoff. Exactly one time, I had a LVE cutoff, when I left the boat for 2 weeks and it rained solid during that time and my solar didn't keep up.
Many thousands of cheap drop-ins have been sold and they go into boats daily. The alarm just hasn't proven to be an important feature. There are a few systems with great monitoring at a cost but the cheaper systems outsell them. Example, several manufactures offer drop in batteries with CANBUS that will talk to a Victron GX device with all kinds of monitoring and alarming possible. So, for anyone that wants those features, they are available. But I don't see them becoming widespread anytime soon.
neutrinornd
New Member
Soon i will share battery monitoring app for JKBMS with sound and visual alarms
