While I don’t recommend intentionally frying your alternator, frying ours last summer pushed this project to the top of our to-do list and I’m glad it did. We spent a lot of money on our Battle Born LiFePO4 batteries and with a new alternator and external voltage regulator I feel more at ease that the batteries are charged and maintained appropriately.
The new Balmar alternator has an internal voltage regulator which would probably work just fine, but we opted to install an external voltage regulator to attain a better performing charging system.
A voltage regulator is really just a voltage limiter. All it really does is limit or maintain a preset voltage once the battery bank gets to the target voltage. External, high-performance regulators can limit voltage based on battery temp, alternator temp, time at voltage & other programmable parameters but in reality, what they do is limit voltage.
Balmar Max Charge MC-614 Voltage Regulator
We bought an external Balmar Max Charge MC-614 Voltage Regulator. To install the external voltage regulator we bypassed the internal regulator in the Balmar alternator and mounted it in the battery compartment away from the heat of the engine.
Some features include:
-
- 8 Selectable Programs for Marine Batteries (including LiFePO4)
- 15 Amp Maximum Field Current
- Advanced Programming Modes
- Alternator & Battery Temperature Sensing & Control
- Exclusive Belt Load Manager Function
- Bright LED Display and Easy Programming Mode
It has to be programmed for your system specifically. Howtomarine.com has a great video about programming it. These are the parameters we set for our system:
Pro:
- bA: LFP (LiFePO4 batteries)
- bEL: b-4 (Belt Load Manager Field Reduction 20%
- dSP: Sd (Short Display Mode)
- bdL: Off (Alternator Fail Advisory Mode Off)
PrA:
- dLc: 10 (Start Delay 10 seconds)
- AHL: 14.5 (Hi-volt Limit or Equalization <14.6)
- CL: 14.4 (Compensation (temperature) Limit)
- Bv: 14.4 (Bulk Voltage 14.4)
- B1c: 0.3 x 6 min (Bulk Time = 18 min @ 14.4)
- Av: 14.3 (Absorption Voltage 14.3)
- A1c: 2.5 x 6 min (Absorption Tie = 2.5 hour @ 14.3)
- Fv: 13.5 off BMS (Float Voltage <13.6)
- F1c: 0.1 x 6 min (Float Time = 6 min)
- ALL: Low Limit 12v
- Fba: Not used (factory default)
- FFL: Not used (factory default)
- AL1: 100C (Alternator Temperature Limit)
- b1L: 52C (Not used)
- SLP: 6.0 mV/C (factory default)
In the video below you can see how to navigate the menus and where we installed it.
It never ceases to amaze me how much we *all* spend to store and manage $0.10-$0.20 worth of electricity…
I’m looking to put together a similar system with the Battleborn/Balmar setup. Do you have the regulator shutoff before the batteries reach 100% SOC? I understand that not having this can potentially damage the alternator.