Ready to jump to Lithium... any advice appreciated!

[tbrady]

Hi All,

I'm very close to purchasing a 100Ah LifePo4 battery from LifeBlue for our 21BHS.  The initial cost is obviously very high but I'm hoping this battery will be better for us since we are off-grid 99% of the time and can usually only run the generator about 4hrs a day depending on where we are camped.  After emails with several manufacturers I have been assured that the WFCO converter in our trailer should be fine for this battery.  My main outstanding question is whether the WFCO will allow the battery to charge fast enough since it doesn't switch over to bulk mode until the battery is below 50% charge.  And for lithium the voltage doesn't drop hardly any until you are beyond 90% discharged.  It's possible I will have to add a separate charger but I'm waiting to see how it goes w/o it.

So...  my plan is to relocate the battery to the back of the trailer near the hot water tank.  This will keep it in a more temperature stable place (these batteries can't be charged if they are below freezing) as well as in a more secure place.  I haven't looked at all into what it will take to relocated the battery.

Does anyone have any input on any of this?   There's not a ton of info out there for what I am trying to do... most people jumping to lithium seem to be doing it with solar and not using the existing power converter etc.

thanks
tim

[DavidM]

Installing a lithium battery in your RV particularly the way you are going about it, is a very bad idea. Why?:

Despite what the vendor says, lithium batteries need very different charging parameters than FLA or AGM batteries. Your camper's converter absolutely will not work. The very fact that the manufacturer say it will work is a very good reason to run, run from this installation.

Also lithium batteries need a load disconnect system in addition to a lithium chemistry specific charger. If lithium batteries get discharged to far, they are toast. I will bet your manufacturer didn't tell you this either.

The ONLY type of of lithium battery system I would consider for an RV is an integrated battery, battery charger and battery management system made from a well known manufacturer. Mastervolt is one of these and they are extremely expensive, well over $1,000 for a 100 Ah battery.

Yes they are lighter than FLAs or AGMs and you can discharge them much more deeply than an FLA or AGM so a 100 Ah battery will go twice as far.

But a simple 100 Ah FLA costs about $100 and an AGM maybe twice that, so at worst $200-$400 for equivalent capacity to a 100 Ah Mastervolt system.

Unless you are desperate to save space and weight or just want to spend a lot of money to be the first kid on your block with a new toy, stick with the tried and true FLA or AGM batteries for your RV.

David

[MitchB]

I'm not as convinced as David is that it's a horrible idea.  BattleBorn batteries makes a 100AH lithium battery with a built in battery management system that they say is a drop in replacement for lead acid batteries.  I've seen many good reviews of these batteries.  If I were going to do this myself the key thing I would look at are the voltages of the WFCO converter in the various stages of charging.  If they are compatible with the lithium battery I think it's not unreasonable to do it.   

[tbrady]

I have spoken to several manufacturers about whether the WFCO is compatible or not and I have received conflicting information. 

Battleborn states - "Yes our batteries are a drop in replacement for lead acid batteries. What does the power controller set the bulk/absorption and the float to? The bulk/absorption should be set to 14.4V-14.6V and the float should be set to 13.6V or a little lower. "

LifeBlue states - "WFCO is not compatible. It will over charge and then let the battery discharge. We recommend Iota DLS chargers. We stock the 55, 75 and 90 Amp models. You can manually change the charge rate with s switch. Soon, Iota will release an automatic charge module for the converter."

From reading the WFCO manual it looks like it falls in to the parameters as stated by Battleborn.  I'm not sure how the WFCO would overcharge the battery though?  Is there a way I could have the battery still supply power through WFCO  but have a separate charger for the battery?  The IOTA charger mentioned by LifeBlue is around $150.

Thanks for the input guys... I need all of it that I can get!   And David, not trying to be the first kid with the new toy by any means.  Like I said, the pros of lithium for how we camp justifies the cost for me.  At least assuming I can get 10 years out of this battery which is the LifeBlue warranty (first 5 yrs full warranty, 2nd 5 years is repair for free but if replacement is required you get 30% off).

[MitchB]

If you're off-grid you could attach any charge controller you like in between your power source and your battery.  For example, I off-grid camp almost exclusively and I use a portable solar panel attached to a Morningstar charge controller in turn attached directly to my battery. The Morningstar controller is a 4 stage charge controller, bulk is 14.4v, float is 13.7v and equalize is 14.9v. If I went to lithium I wouldn't use this controller because the equalize voltage is a little to high. You said you use a generator, I'm assuming you plug your 30 amp cable into the genny and then into the side of the camper.  You could instead run from the genny to a charge controller and then from the charge controller to the battery (If I were going to do this I'd use an inverter generator with nice clean power). Of course this would prohibit using the 120v outlets in your camper but all the other stuff, lights, water pump, fridge on propane, would be fine.

I'm somewhat confused as to why Lifeblue would say that the WFCO isn't compatible if the voltages are okay, perhaps it's the BMS on their battery, I don't know.

[Merlin]

I just checked into Battle Born batteries for my off the grid solar system at my cabin. I did not go with them because of the cost and the operating limitations for temperature. Had I been able to use them (and afford them!), I would have also used a lithium battery charger. There are several reputable companies now making them for the lithium batteries, including Progressive Dynamics and Iota. If it was me, investing mega-bucks in lithium batteries would for sure mean providing them the 2 stage charger and voltage they need for each stage. I went with conventional lead-acid AGM batteries that will serve my purpose well and last for many years. Next time around for my camper, I may look again at Battle Born.

A member of the Land Cruiser forum I'm active on just installed a Battle Born battery for his house battery in his Land Cruiser for the fridge, lights, inverter, etc. Along with that, he installed a Redarc battery management system to keep both the house battery and starting battery (which is lead-acid) properly and fully charged. On his recent trip to Baja, it worked GREAT!

Trailer Life magazine has run some recent articles on the popularity of changing from lead-acid to lithium batteries in RVs. Here is on ad for the Progressive Dynamics converter for that purpose, making the changeover easy (and painless for the new battery).

http://www.trailerlife.com/rv-gear/gear/seamless-li-ion-swap/

[tbrady]

Thanks Merlin... I'll do some more reading.  And Mitch, they said the reason the battery can get overcharged is "Absorb timer can not be reduced to 0-15 minutes.".  That doesn't make any sense to me but I know very little about all of this...  Battle born seems fine with WFCO and their battery parameters are almost identical to LifeBlue.  I reached out to WFCO and their tech told me the only problem using WFCO is that their converter could only get the battery to about 90% charged (which is probably a good thing).

Also, for WFCO to enter bulk mode the lithium battery would almost have to be completely depleted for it to kick in.  So... I still have emails out to some places to get more info.  With what I know at the moment I would feel ok getting the LifeBlue and trying with the WFCO initially to see how it works.  The LifeBlue battery has a bluetooth monitoring app I can use to see how things are going.  There's a really good chance I would add a proper charger for it and a battery cut-off switch.

Which leads to another question...  could I run the LifePo4 charger directly from rv(house) power?  E.g. I run the genny which is plugged in to the trailer like normal and I plug the charger into an outlet in the trailer.

thanks for the help guys!

[MitchB]

I'm thinking you couldn't run a separate Lithium charger from house power unless you prevent the WFCO from also trying to charge the battery while the generator was running.  I assume that now when you run the genny the WFCO automatically begins charging your battery as well as providing 12 volt power as needed?

[Diversteve]

Here you go.
https://handybobsolar.wordpress.com/
this guy knows.

[Merlin]

I forgot to mention in my last post that the current issue of Trailer Life (May, 2018) has a full tech article on installing lithium batteries in an RV. They installed 2 Battle Born LiFePO4 batteries, a Xantrex programmable charger with a monitor, and a lockable battery box on the tongue. It's becoming a popular conversion and the tech info in the article is excellent.

And I would note that MitchB is correct in his post this morning that you have to be careful to not create a charging loop by hooking up a separate charger to shore power that is already hooked up to the trailer converter!

[DavidM]

I have gotten a bit more educated about Li battery systems, particularly those for RVs in the last few days. Here  is my take:

The two manufacturers of Li battery systems mentioned here, Battle Born and LifeBlue, both have built in management systems that protect the batteries in case of low voltage, high voltage and other faults. That is good.

The other thing I have read more about is charging parameters for Li batteries. I do believe that the standard Progressive Dynamics converter on our campers does not meet these parameters. PD says that right up front in their website. PD does make an LiFePO4 specific converter that does meet the general requirements and I would definitely replace my existing converter with one of these if I were to install an Li battery.

I do believe that a system with one or more of these batteries and a PD9100L converter will be reasonably safe. Whether it is economical is another question.

David

[tbrady]

Hey Guys,

Got a little more info...  According to Larry Crutcher who is supposed to be an expert in this area. 

"No. Overcharge, holding absorb voltage on after the battery is full, is not protected. That is why you must always use the right charger for ANY battery type, not just Li-ion. The EMS has many other protective features. See attached data sheet.

Beware of some chargers that claim to be Li chargers but are not, like these: https://www.progressivedyn.com/specialty/pd9100l-series-lithium-power-centers/"

So... it sounds like WFCO is no good.  Even though BattleBorn is telling me it is and WFCO told me it wasn't capable of fully charging the battery anyway. 

I have contacted BattleBorn again to ask them about the overcharging specifically...  I'll let you all know what I find out.

[DavidM]

If you don't believe that the PD9100L charger is ok for Li batteries then who DO you trust? PD is a major supplier to the RV industry. So is WFCO.  Battle Born and LifeBlue must be relatively small companies. Do you trust them more than PD or WFCO? PD has a Li specific converter. WFCO announced a new Li converter design about a year ago, but i haven't seen any evidence of one yet.

With the confusing answers you are getting: the standard WFCO converter will work, the PD Li specific converter won't work, then I guess I go back to my original statement: Go with a known supplier of (marine in this case) electrical systems like Mastervolt. I would trust those guys. They have a 100 Ah Li battery system but it is more expensive than the others. They also make battery chargers, which aren't cheap either, which will charge their Li batteries.

Buying these two critical components from one well known company makes sense to me. But the cost will probably double, particularly for the charger.

David

[tbrady]

Yeah, I know David... the conflicting info sucks :|.  I'm just quoting exactly what Larry said.  I'm going to do a little more research but at this point I'm leaning towards just going the 6-volt route.  I do believe lithium would work better for our needs but I don't want to spend that much  money with all the conflicting info I am getting.

Maybe if there was "something"  I could put between the WFCO and the battery to stop it from charging the battery... according to WFCO the only way to stop it is to disconnect it but then I would have to remember to always disconnect the battery when on shore power.

[tbrady]

Ok, just got another reply from Battleborn and although they didn't answer my question directly they did seem to indicate that their BMS would protect the battery from overcharging.  Also, on their table listing power supplies they have tested WFCO is one of them...  I put the text of the email below.

I have what I think is a great idea.  If you guys will send say $300 each I will use the money to buy the components and figure out exactly what all it will take to get this to work.


Hey Tim

The BMS protects the lithium cells from getting damaged in several scenarios. From low or high voltage, low or high temperatures, or if there is a short in the system. The BMS will shut off the battery to protect the li-ion cells and the user of the battery from unsafe operating conditions.

The BMS also regulates the amount of power you can take out of the battery. The BMS on our 100 amp-hour battery is rated to 100 amps continuous, 200 amps for 30 seconds and any higher loads for ½ second.

Our BMS also keeps all of the cells in balance. At the top of each charge cycle, the BMS reduces the charging rate in cells that have been topped off first, letting the rest of the cells catch up. This ensures that the cells are always in balance, and maintains the quality and efficiency of the pack.


Thank you

Joey L
info@battlebornbatteries.com
775-525-2472 Direct
855-292-2831 Toll Free
Battlebornbatteries.com


From: Tim Brady <tbrady@outlook.com>
Sent: Friday, April 20, 2018 11:38 AM
To: Battle Born Batteries <info@battlebornbatteries.com>
Subject: RE: lifepo4 battery

Thanks for the help Joey.  Was doing a bit more research before I pulled the trigger on this and was told that the WFCO converter could overcharge these batteries while in absorption mode and this is something the BMS is unable to protect against?  Basically that being in absorption mode for 15mins was bad for LifePo4 batteries...

Here is what the specs say on our WFCO

"If the converter senses that the voltage is less than 13.2 Vdc it will automatically go in to bulk mode.  In this mode the output voltage will switch to 14.4 for a maximum of four hours.  If the RV is not being used for 48hrs and shore power is plugged in it will go into float mode and charge the battery with a trickle voltage of 13.2.  When the converter senses a demand it will automatically switch to absorption mode which is 13.6 Vdc.  The normal mode of operation is absorption mode."