My research is failing me.
I can’t seem to set my Bulk voltage on my 150/70 solar controller for my LifePo4 Battleborn batteries. Battleborn says Bulk voltage should equal Absorption of 14.4 volts.
The controller charges Bulk at 13.6 volts no matter what I try.
Any Ideas?
Bulk is just the charger trying to reach Absorption voltage using the maximum available power. If you’re seeing 13.6V in Bulk, it’s likely just because there’s not enough amperage available to reach the 14.4V set for Absorption (possibly because the sun isn’t high enough in the sky, or the batteries are low).
Normally you just set your Absorption voltage to 14.4, and then the solar controller will give the batteries all the amperage it can until 14.4V is finally reached, at which point the controller will change to Absorption mode and the adjust amperage to maintain 14.4V.
Hello Travis.
Thank you for the reply.
Yes, that’s exactly what happens. 13.6 until absorption then 14.4 as I set in the settings.
However, I guess I’m old school in dealing with power supplies. I set the voltage as priority and it sends amps as set or up to its amp limit.
Battleborn says charge at 14.4 Bulk=Absorption. I hope I’m not degrading these batteries by the majority of charging at 13.6 until the very end.
P.S. I’ve read on other forums that 13.6 is the bulk voltage for them as well. Not 13.2 or 13.8, but very specifically 13.6. That’s why I suspect this a factory set number.
Ah, I see what you mean about Battleborn recommending a Bulk voltage of 14.4V.
I don’t have a ton of experience with LiFePO4 battery banks, but I believe they’ll accept a lot of amperage before the voltage increases beyond that mid-13V figure, unless they’re very near 100%, so I think your scenario sounds reasonable.
I think BB’s recommendation for Bulk/Absorption being 14.4V is hopefully just for a maximum voltage, as I think it would take a lot of charging amps to get a LiFePO battery up to 14.4V, or even beyond 13.6 when not near fully charged.
Maybe someone else with BattleBorn LiFePOs can chime in to confirm their experience, but I believe the behavior you’re seeing is nominal.
Battle Born batteries need to see 14.4v for their balancing board to kick in, so Bulk/Absorb should be set to 14.4v and Float around 13.6 to 13.8.
Travis is correct - your charger will show less than 14.4v as it’s charging because its output voltage is being dragged down by the load of the battery. Once the battery reaches 14.4v, the charger will kick over into Absorption mode, where it should stay for -rule of thumb on Battle Born batteries- around .5 hour per 100Ah of battery, then the charger will kick into Float.
Thanks Justin
I didn’t know about the 14.4V for .5hr for every 100Ahr.
I have three 270 Ahr BB, 810Ahr total in my RV.
Before leaving home I isolate them and charge one at a time.
When they reach 14.4 (my absorption setting) they almost immediately go to the float voltage setting and I stop charging and charge the next one.
If I need keep them at 14.4 for .5 hr for every 100Ahr, I’ll set my float voltage to 14.4 and keep it there for 1.35 hours.
I’ll experiment with that on Monday.
That sounds like you have the GC3s? Have a look at their manual, they’re pretty explicit about how to charge the battery: https://battlebornbatteries.com/wp-content/uploads/2022/10/BBGC3-Manual-Edition.PIM_BBGC3Rev020_04242024.pdf?srsltid=AfmBOoqqBVNjWXpyut_vmffHkNnMa-TF1XX5D2lwaIvVFVaQ4wYqu1IC
Don’t set your float to 14.4, Float should be between 13.4 and 13.8.
Set your bulk/absorb to 14.4, and absorption time (in the case of the GC3) to 60-90 minutes per battery, in accordance with the battery user manual.
It’s not the GC.
It’s the model that came out before.
Thanks for all your reply’s
BB wants the entire charge cycle at 14.4. Bulk=Absorption. There is no float for the BB.
I’ve spent years trying to figure out how to do that.
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You can only achieve bulk at 14.4 if you have a huge charger. What I believe Battleborn are saying is if your charger has a setting called bulk then set it to 14.4, the same as absorption. This is because some chargers have/had a different target for bulk and once reached and held for a period then went to constant voltage for a period at bulk voltage then dropped to absorption. A voltage listed under bulk is the target voltage for the end of bulk.