Upgrading to LiFePO4 question

[jimkamery]

I have ordered a 12V 300AH LiFePO4 battery with built in BMS to install in my 07 Outlook. I previously installed 500W of solar on the roof and have a programmable MPPT solar charger. My question is.... do I need to change the original 12V Battery charger built in to the Outlook with a special LiFePO4 charger? And what about when the engine is running and you are charging the battery through the engine alternator. Hoping to get responses from people who have already made the conversion. Thanks!

[creativepart]

I haven't already done this... but

1. You need to either change out the charger in your converter/charger to one that is LiPo compatible, or find out if yours can be setup to work with LiPo batteries (unlikely in a 14-yr old motorhome).

2. As to alternator charging the two most common ways of handling this is with a battery isolator that regulates your alternator's connection to the battery OR by installing a DC to DC charger. With this the alternator sends power to the DC to DC charger which is a LiPo compatible charger.

Also, don't forget to re-configure your MPPT solar charge controller for LiPo batteries.

[DavidM]

The Progressive Dynamics 9180 ALV is a good Li specific charger.

Another way other than a DC to DC charger is to replace the existing battery isolation manager which I suspect is the Intellitec BIRD solenoid type with an Li specific BIM, the Precision Circuits Li-BIM 225. This BIM cycles the chassis alternator 15 minutes off and 15 minutes on to limit current.

But it won't charge Li batteries to the last 80-90% SOC. The DC to DC charger should do that if it is set up for Li batteries.

David

[jimkamery]

I just looked at the Progressive Dynamics chargers. Thank you for the lead. Honestly, I believe the 45A or 60A is going to be just fine for my Outlook. That is now on my list. As for DC to DC chargers, about the only brand I am seeing is Renogy and I don't have warm fuzzy feelings about that brand. But I would like the DC to DC charger to get me close to 100% charge on long travel days. Does anyone have a good experience with another brand of DC to DC chargers?

[DavidM]

I would go with the largest capacity shore power charger that will work with your new Li batteries. This will minimize generator run time if you are recharging with the generator.

Victron a very respected marine and RV electronics manufacturer has a nice line of DC to DC chargers. Here is a 30A one on Amazon https://www.amazon.com/Orion-Tr-12-3...s%2C268&sr=8-3. Not sure if they make a 40A one.

Redarc even though they may be an obscure brand makes good stuff and has a good US based customer support team easily accessible by phone.

Different chassis/engine builders have different limitations for charging current from their alternators. I think that the Mercedes Sprinter recommends staying under 40 amps. I bet the Cummins diesel can go much more than that. Not sure about any of the gassers like the Ford V10 or the new V8. I would be surprised if it couldn't go significantly higher than 40A.

I have read one report on this or the Thor forum of someone getting 75 amps out of the alternator into a 200+ Ah Li bank with the Li-BIM 225 when it is in its on mode.

David

[sajohnson]

Redarc makes good equipment. It is rugged and environmentally sealed. It's also relatively expensive, but worth the extra $ if mounting in an exposed location..

I was originally planning to install a Redarc DC-DC charger in our (open) battery box. For now I've decided to hold off on a DC-DC charger and just use the charger in our Magnum MS2000 inverter. I'm not suggesting that everyone should have one, we installed it for a different reason, but since we have it we might as well use it. The charger puts out 115A, perfect for 2 LiFePO4 batteries. I plan to run the (QD3200) generator while driving -- that way it won't bother us or anyone else. The MS2000 charger will bring the batteries up to 100% very quickly.

Another (non-sealed) brand of DC-DC charger that looks good is "Kisae".