Thor Forums

[The_Breeze]

Hi guys,
Background:

Originally Posted by LowOnCash

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Regarding the engine Alternator, since Lithium has a very low internal resistance the Alternators charging circuit thinks the battery is dead and can cause the alternator to run at full power resulting in over-heating of the windings and bearing. Instead of the BIM On and Off times isolator, I highly recommend MasterVolt Charge Mate Pro battery isolater / charger since it is a smart charger which electronically limits alternator output to 40 or 90 amps well within the warranty of the chassis maker

Originally Posted by Beau388

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The charging profile for LA and LFP batteries is exactly the same: bulk (constant current), absorption (constant voltage) and float (trickle charge). For a flooded deep cycle, the max cell charge voltage (resting) is 2.13 volts. The min charging voltage at 70 F degrees is 2.22 volts with a recommend charging voltage of 2.35 to 2.45 volts. That's 12.78 volts for 6 cells in series and 14.1 to 14.70 volts for 6 cells.

So any voltage above 3.28 volts will charge a LFP cell or for 4 cells in series 13.12 volts will charge the battery. Admittedly it will take a fairly long time at 13.12 volts. The higher the voltage the shorter the charge time and so it is with LA batteries. The slower you recharge a battery the longer its life. For 400 cycle life, Lifeline recommends 10 to 13% charge in amp-hp. So for 400 amp-h LA battery bank, that would be a current of 40 to 52 amps. The recommend max charge current for Battle Born's LFP battery 50% charge in amp-h, so for the same 400 amp-h LFP battery bank that would be 200 amps and that would equate to aprox 2,000 cycles from 100% down to 20%. Again less current will lengthen the cycle life of the battery.

I ordered 4 Battle Born LiFePO4 100ah batteries, the BIM Beau suggested and an AIMs 2500w inverter with a lithium charge profile.

Whose right and whose wrong in the above comments? I lean towards Beau but the contradiction in LowOnCash's and Beau's explanation have caused some angst.

My RV is my home until I exit the lifestyle. I don't need to burn my house down in the process or ruin a $4k battery investment. More if you count the rest.

It's not your job to get me through this. It's mine. I've been doing my research but if I'm going to double check myself out here and there's contradictions, please be clear about what you're trying to convey. I'm not trying to start a war. Just be as smart about it as I can while doing the work myself and learning along the way. This is as much a knowledge quest as a quest for reducing gen time.

The batteries are LiFePO4. I'm not sure what lead to the difference in the comments. If you can clear it up, I'd appreciate that a lot.

I have a question into Battle Born:
"I ordered your BIM. I’m being told this is not the right BIM for the job. This is an RV application. Please confirm.

https://www.mastervolt.com/products/...e-mate-pro-90/

'Regarding the engine Alternator, since Lithium has a very low internal resistance the Alternators charging circuit thinks the battery is dead and can cause the alternator to run at full power resulting in over-heating of the windings and bearing. Instead of the BIM On and Off times isolator, I highly recommend MasterVolt Charge Mate Pro battery isolater / charger since it is a smart charger which electronically limits alternator output to 40 or 90 amps well within the warranty of the chassis maker'"


Thanks.