Wow, that's awesome! Can you please share the brands of the batteries and other components?Bought a boat last fall with LIFePO4 (4 x ReLion 100ah batteries). PO upgraded the entire charging system to support the installation. I love that the batteries discharge without a significant voltage curve, and that they recharge quickly since I can put high amperage into them. This will also reduce the amount of time it takes to get most of a charge into them while on a generator. Also I appreciate that the internal BMS protects the batteries from a number of damaging situations. Over the winter I had an event which caused the batteries to discharge until the internal BMS shut them down. I was able to charge them right back up without damage. Most other battery chemistries would've been killed by that. I also like the fact that I have 120 lbs of LIFePO4 batteries compared to 560 pounds of AGM batteries to get the same useful amp hours.
Thank you for the quick and complete reply! I'm a bit confused, though. First, you have a 24V regulator and a 12V charger/inverter. How does that work? Also, none of the components except, of course, the batteries, seem to be LiFePO4 specific. Finally, do you know what BMS is in the batteries? Is it one, or one per battery?- ReLion LiFePO4 100ah batteries x 4
- Balmar MC-624 regulator
- Balmar SG-200 Battery monitor with shunt and bluetooth
- Balmar 120 amp alternator
- Xantrex Freedom SW2012 shore charger/inverter
- Xantrex Xanbus system control panel
- Bluesea Mini ACR (for Starter battery)
Sorry, wrote that wrong, its the Balmar MC-618 12v regulator. Good catch! The BMS internal to the batteries is from the manufacturer, ReLion, but no info beyond that.Thank you for the quick and complete reply! I'm a bit confused, though. First, you have a 24V regulator and a 12V charger/inverter. How does that work? Also, none of the components except, of course, the batteries, seem to be LiFePO4 specific. Finally, do you know what BMS is in the batteries? Is it one, or one per battery?
Thanks,
jv
A couple of questions.- ReLion LiFePO4 100ah batteries x 4
- Balmar MC-624 regulator
- Balmar SG-200 Battery monitor with shunt and bluetooth
- Balmar 120 amp alternator
- Xantrex Freedom SW2012 shore charger/inverter
- Xantrex Xanbus system control panel
- Bluesea Mini ACR (for Starter battery)
Good questions! I'd like to know as well. For the first, some BMS's have an output to enable/disable alternator field current, so they can shut off the alternator before they dump. For the second I'd say no, but what long term damage will that do to the starting battery? Perhaps better a DC-DC charger than an ACR.A couple of questions.
How is the alternator protected from a BMS dump?
Do the start battery and the LFPs have the same charging characteristics, i.e, are the absorption voltages the same?
Good questions! I'd like to know as well. For the first, some BMS's have an output to enable/disable alternator field current, so they can shut off the alternator before they dump. For the second I'd say no, but what long term damage will that do to the starting battery? Perhaps better a DC-DC charger than an ACR.
The easy one first: My start battery does have similar charging characteristics as the lithiums.A couple of questions.
How is the alternator protected from a BMS dump?
Do the start battery and the LFPs have the same charging characteristics, i.e, are the absorption voltages the same?
True, but that limits your options. The BMS must be able to warn the regulator that it will dump the load and the regulator must be able to act fast enough to cut the field current. This limits options for installation.If you have a BMS that will cut the field current before it dumps you will be fine. That is the way it should be. The APM can well be a single use device, even according to the manufacturer.
(emphasis added)Module which helps protect the alternator’s diodes and internal regulator against spikes (clamping up to 60V) and sustained over-voltage conditions (beginning around 20V) for the 12V version. The APM can absorb multiple surges of such energy, and can absorb surges in excess of 200 amps without failure to continually protect your alternator. Visual and audible alarms indicate if the device has been compromised and needs replacement.
I saw this on the the data sheet:True, but that limits your options. The BMS must be able to warn the regulator that it will dump the load and the regulator must be able to act fast enough to cut the field current. This limits options for installation.
The Balmar APM can absorb multiple surges. From the Balmar Website:
(emphasis added)
That said, a BMS can control an external relay in series with the field current wire, and drop it just before it dumps. I think that's how some of them work.In certain cases it is possible that the APM will provide protection, but in the process become damaged so that it no longer provides protection.
The Balmar statement is a CYA. And there are trade offs. Yes you can get a BMS that signals the regulator but that drives you into a more expensive solution. If BMS load dumps were a frequent occurrence, then more caution would be needed. However, if the regulator, PV controller, and charger are programmed correctly, a load dump would be a very rare occurrence. Thus we have 2 rare occurrences, a BMS load dump and a failed APM. The combination of both is very very rare. I'll take my chances.I saw this on the the data sheet:
That said, a BMS can control an external relay in series with the field current wire, and drop it just before it dumps. I think that's how some of them work.
That's fair. I would hope a BMS dump would be rare, or never!The Balmar statement is a CYA. And there are trade offs. Yes you can get a BMS that signals the regulator but that drives you into a more expensive solution. If BMS load dumps were a frequent occurrence, then more caution would be needed. However, if the regulator, PV controller, and charger are programmed correctly, a load dump would be a very rare occurrence. Thus we have 2 rare occurrences, a BMS load dump and a failed APM. The combination of both is very very rare. I'll take my chances.
Lithionics external BMS will do that, but it’s a seriously pricey installation.That's fair. I would hope a BMS dump would be rare, or never!
I was designing a system last year, but left it and can't remember everything now. But I recall being disappointed that not everything was "there" yet for LiFePO4. All of these systems, it seemed, Victron, for example, assumed or required a lead-acid battery in the system. One would think that a BMS would emerge that controls the alternator as well, as an integrated system, and then you'd never have to worry about zapping alternator diodes.
Great, thank you! I used to follow Panbo but it became tedious. Maybe I'll start again.Lithionics external BMS will do that, but it’s a seriously pricey installation.
Battleborn is about to release its’ IntelLigence line, with some type of mesh network and CANBus. They own Wakespeed so it’s possible they will be some control interface there.
MIBS 2023 - Battle Born with Dragonfly IntelLigence
Battle Born Batteries is introducing IntelLigence a line of LiFePO4 batteries and accessories that communicate via wireless mesh networkpanbo.com
I couldn't make it through more than five minutes or so of this, it's so self-absorbed and tedious, thanks anyway!This video should give you pause about installing a system with a single external BMS. I understand the issues regarding FETs vs contactors, but I believe in a simpler, more redundant solution.