TheSamba.com :: View topic - LiFePO4 battery in the engine bay -- Yeay or Nay?

Tue Aug 01, 2023 4:16 pm

I have a 100A Renogy Lithium Smart Battery setup that I'll be planting into our Riviera but I'm in a quandary about its location.

I would love to put it in the empty space that is available on the left side of the engine bay but I'm not sure if the engine heat will be bad for it. The other option is under the rear seat/bed. I don't want to put it there if I can help it because that is useful storage space when we go camping.

Anyone with a lithium house battery setup have experience with it in the engine bay? Good/bad? Do I just bite the bullet and mount it and the DC/DC on-board battery charger in the cabin (and punch holes in the body to route the wiring)?

Tue Aug 01, 2023 4:49 pm

I had similar thoughts with my vanagon.
I think the heat may be a problem, but mayboe more importantly -the cold. I'm not sure how cold it gets where you live/drive - but extreme cold (and being really exposed in the engine bay) is not good for the batteries.

The BMS on it will prevent it from charging or discharging when it is below a certain temp.

Keeping it somewhere in the cabin helps to keep the temp closer to the range the batteries like.

This is what I read elsewhere - I'm far from an expert on this...
I did squeeze one in under the seat of my vanagon. Unfortunately it got so cold in the white mountains of NH - then it took forever to warm up to the point that is was useful...

Tue Aug 01, 2023 6:34 pm

i run 2 x 100Ah LiFePO4 batteries in the engine bay... in both of my campers

im using 4 x "Aolithium" bluetooth 100Ahs and they are great. epoxy terminals and basically sealed. i do take the case lid off and put butyl tape and torque it back down just in case. no issues. i'd say it's easily marine grade

the renogy batteries i had before, however, had issues .. their ports would get full of water and the battery would freak out and do strange things .. and fail. they worked, but they were not totally reliable - particularly the passenger side which was oriented with the RJ45 ports more in the direct path of water ingress. they claim IP54 aka "Protected from water spray from any direction" on the current version of the 100Ah LFP but they fell short. renogy engineers actually examined a couple of my RMA batteries across a couple versions of the product (i was a pretty early user, had multiple failures, multiple replacements, etc.) and were trying to improve the product based on what they saw. they were responsive, communicative and attentive in dealing with the issues...although it was still a real PITA.

i think you could probably run the 2 x renogy in a bus bay just fine, though, if you prepared things properly.

i would consider filling the RJ45 ports with dielectric grease and keeping the rubber covers on them...possibly space the case bottom off the "floor" of the tray (and make sure it can drain) if you are mounting them without an enclosure/ baseplate ... perhaps putting a lid over the battery to deflect water - that's what i suspect the main issue is when used in a bus....the engine bay vents tend to make the battery tray a direct drain path when a bus sits in the rain.

i don't see why you couldn't make it reliable with a little extra care.
on paper, they ARE rated for direct water spray...so you aren't doing something horrible and out-of-spec. there are some nuances about the specific environment in a Bus engine bay, though

if you are somewhere where the LFP's will end up being @ 32F or lower a lot, there are battery warming blankets that you can use .. i've always thought having 2 x in the bay and 1 in the interior (where i'd have heat) might be another option ... haven't had to deal with LFP in freezing conditions much TBH though. i'd imagine a water cooled temp engine would tend to keep the batteries pretty warm, but a regular ACVW engine tends to keep the engine bay right around ambient while in motion. a LiFePO4 can discharge from somewhere around -4F to 140 to 175F .. so, starting the engine is not really something you'll need to worry about .... but it usually won't allow charging once you hit freezing (32F) - the battery won't stop working it just will not draw any charge.

personally, i am a huge fan of 2xLFP in the engine bay...bridged together, no isolator..with voltage disconnect on your troublesome consumers (refrigerator and inverter usually have that built in by default.. water pump/ heater/ etc can sit on a victron bluetooth batteryprotect).... it's awesome. ~200Ah of LFP makes for an awesome vanlife'n type bus.

for any lithium it's good to check if Will reviewed it
https://www.youtube.com/@WillProwse
his teardowns are great

Wed Aug 02, 2023 12:46 pm

Thanks for your excellent experience & input MH. I spoke to a couple of owners w/solar systems in their Bus and they said 100A is plenty, like, overkill for camping. Fine by me! Also, I'm sticking with a 12V system. Thus my battery decision.

Will gave it a very good review: https://www.youtube.com/watch?v=aahHWaV6Zdk

Yes, I'm aware of water and will be looking to build a non-conductive hat for it. I'll see what I can build for a battery tray to keep it secured & off of the floor and still allow drainage.

Our Bus is in my heated shop so it's protected from the elements. Usage will be for warm weather use as I really can't see my wife wanting to endure Oregon rain and cold temps during the winter time (that's where our timeshare comes in!).

I'm thinking of maybe making a removable heat shield for summer use (shield between battery and engine) and another one for winter use (shield on left side of battery so weather is blocked but heat from engine can reach it). Just brainstorming phase right now.

Though I don't have a solar panel for it now I am looking for a good, portable unit as the DC/DC charger is meant to handle it (alternator & solar charging). I did get a smart wall charger for it to keep it maintained when parked in my shop.

Wed Aug 02, 2023 1:24 pm

Air_Cooled_Nut wrote: Thanks for your excellent experience & input MH. I spoke to a couple of owners w/solar systems in their Bus and they said 100A is plenty, like, overkill for camping. Fine by me! Also, I'm sticking with a 12V system. Thus my battery decision.

Will gave it a very good review: https://www.youtube.com/watch?v=aahHWaV6Zdk

Yes, I'm aware of water and will be looking to build a non-conductive hat for it. I'll see what I can build for a battery tray to keep it secured & off of the floor and still allow drainage.

Our Bus is in my heated shop so it's protected from the elements. Usage will be for warm weather use as I really can't see my wife wanting to endure Oregon rain and cold temps during the winter time (that's where our timeshare comes in!).

I'm thinking of maybe making a removable heat shield for summer use (shield between battery and engine) and another one for winter use (shield on left side of battery so weather is blocked but heat from engine can reach it). Just brainstorming phase right now.

Though I don't have a solar panel for it now I am looking for a good, portable unit as the DC/DC charger is meant to handle it (alternator & solar charging). I did get a smart wall charger for it to keep it maintained when parked in my shop.

Look into what boondockers and people with travel trailers do. They deal with the temps too. I just installed three 100aH LiTime Lithium batteries for my RV. I put them into the same space as the existing two Group 24 batteries. I have no idea how they will perform over the long haul but I decided to give it a shot. When I did it I did get a DC-DC charger too. On the other hand, I have a 4000W inverter and 800W of solar on my RV.

If you are looking for insulation, then look at Jegs or Summit. They pretty much got whatever you need on that department which works for cars.

On the left side of the engine compartment, my dad always had a 2.5 gal container of gas stored there when I was growing up. After the engine change (battery went there as the dry sump tank ended up being on the right side) it became the can to refill the lawn mower. Amazingly enough, I found it a while back.

I can't imagine my dad asking here on the samba, back in 1969 if storing gas there was a good idea. I bet that thread would be over a million posts by now.

Thu Aug 03, 2023 9:24 am

jjvincent wrote: ...

On the left side of the engine compartment, my dad always had a 2.5 gal container of gas stored there when I was growing up. After the engine change (battery went there as the dry sump tank ended up being on the right side) it became the can to refill the lawn mower. Amazingly enough, I found it a while back.

I can't imagine my dad asking here on the samba, back in 1969 if storing gas there was a good idea. I bet that thread would be over a million posts by now.
:lol:

Thanks for the input and insulation sources. And the humor!

Thu Aug 10, 2023 11:41 pm

Air_Cooled_Nut wrote: I spoke to a couple of owners w/solar systems in their Bus and they said 100A is plenty, like, overkill for camping.

IMO If you run a fridge, water pump and inverter 200Ah can be a lot better than 100Ah .. all depends on the loads and how you use it. On my Riviera the fridge goes 24-7-365.... A single 100Ah is a great place to start and with solar can be enough for some real luxury.

For something easy and cheap - portable folding solar panels like this one are nice. I preferred using this one over my more fancy Renogy portable panel with the rigid panel.

https://www.amazon.com/TP-solar-Foldable-Portable-...0&th=1

Quote: Fine by me! Also, I'm sticking with a 12V system. Thus my battery decision.

Will gave it a very good review: https://www.youtube.com/watch?v=aahHWaV6Zdk

Yeah. The Renogy bluetooth batteries are nice... they just aren't 100% sealed, so need to be careful. The key difference between the Renogy and many other batteries (including the famous BattleBorn) is that the Renogy was one of the first to use "pouch" LiFePO4 cells .. instead of cylindrical cells .. so you have a bunch of flat packs of lithium stacked on top of each other..so they are super space efficient compared to stuff like the BattleBorn where you have empty space between the cylinder shaped batteries..because they are round you have a lot of wasted space. I don't believe BattleBorn 100's even fit in the Bus standard battery spots.

Quote: Yes, I'm aware of water and will be looking to build a non-conductive hat for it. I'll see what I can build for a battery tray to keep it secured & off of the floor and still allow drainage.

Our Bus is in my heated shop so it's protected from the elements. Usage will be for warm weather use as I really can't see my wife wanting to endure Oregon rain and cold temps during the winter time (that's where our timeshare comes in!).

I'm thinking of maybe making a removable heat shield for summer use (shield between battery and engine) and another one for winter use (shield on left side of battery so weather is blocked but heat from engine can reach it). Just brainstorming phase right now.

Yeah, keeping it from getting flooded out with water is a good idea. For heat, if you're running an air-cooled engine, you don't really need anything. I ran a Bluetooth temp sensor ("SensorPush") in the engine bay and data logged...if the car is driving the engine bay temp is basically the same as ambient (the difference is very little).

Quote: Though I don't have a solar panel for it now I am looking for a good, portable unit as the DC/DC charger is meant to handle it (alternator & solar charging). I did get a smart wall charger for it to keep it maintained when parked in my shop.

Solar makes all the difference.

Having a DC-DC is nice but it's also fine to run the LiFePO4s off the alternator if needed (ideally you have it regulated at 14.4V). The DC-DC is good for not pegging your alternator to max output 100% of the time and cooking it...and good for making sure your battery is always getting proper voltage despite whatever is going on with the rest of the electrical system. So, a nice thing to have.

Ironically, split charge systems typically screw up the voltage going to the house battery..... the common diode based on ones can really put a serious drop on the voltage. I swear a lot of people aren't even getting their house batteries past 60% charge with some of those things. IMO split charge is working against you ina Bus, you end up with a starter battery that takes up tons of space in a vehicle where every inch is precious... and that starter battery does nothing for you other than spin the starter and then just sits there doing nothing...i always say just run 2 LiFePO4s, connect em together and go :) (do be mindful of your whole system and usage though and not leaving yourself with 2 totally flat batteries....still easily avoided without having to go the super typical nuclear route of a split charge setup)

Sounds like you have an onboard 110V AC ("wall") charger on there? Those are great to have permanently installed on the vehicle...it's nice to install it and power it directly off the 110V camping power inlet that campers typically have..then whenever you are on "shore power" your battery charger will be running...you can also wire that 110V inlet to a transfer relay like a Xantrex PROwatt .. and have it "automagically" power an outlet on the interior of the bus via inverter or "shore power" based on whatever preferred source is available. Which is nice with inverters like the Victron that provide a load-sensitive cut-on, and go to sleep (so they don't draw phantom loads) when there is no load.

Fri Aug 11, 2023 3:34 pm

What I got from Renogy aside from the battery:
12V 20A AC-to-DC LFP Portable Battery Charger
DCC30S 12V 30A Dual Input DC-DC On-Board Battery Charger with MPPT
Renogy ONE Core & BT-2
Not running a fridge. Not running anything except the stereo and interior lights (LED). The plan is to get a nice compressor-type cooler for portability. We have an empty cabin and wish to keep it that way i.e. no cabinets.

Mon May 06, 2024 2:28 pm

So, Im happy to contribute after being a voyer for years on Samba. Thanks to everyones contributions.

So I have gone down the rabbithole. I wanted a 12v cooler, so in order to do that wanted to upgrade the battery to 100AH lithium.

To make this all work I got the renogy (MMPT?) charge controler that has replaced my older isolator and now my alternator can properly chage a lithium battery to 14.4 volts.

I mounted the Renogy charge controller (not small) on the back of the rear cabinet (I have a 74 bay, nothing original).

I have the solar panel hook ups juist inside the engine bay so I can run a connection out the engine bay door or up through the "ear" if I have a panel on the roof.

THE PROBLEM
The lithium battery that I got from Amazon (pretty sure its the same as the renogy one) is a tad too tall to fit under the spare tire well that comes down from above over the left side of the engine bay. It appears I have about 8" from the metal lip to the lowest point of the tire depression.

The bus looks awesome but its had lots of work. Perhaps this problem is from the replacement of the tray on this side?

I may end up jacking the lowest point of the tire well to gain the clearance I need.

Anyway, I now have the charge controller installed but no lithium battery yet. Still a ways from the 12V cooler that started this mission.

Tue May 07, 2024 12:40 pm

Hey, I opted to fit mine under the seat along with the DC-DC charger, AC Charger and solar charger. I posted about it on this Facebook forum with pics and was pretty pleased with the results.

https://www.facebook.com/groups/1490750441142504/permalink/3162483463969185/

Tue May 07, 2024 12:46 pm

So I did a bit more research and it is possible to mount a lithium battery on its side which may be the option. Not ideal but I want to keep the house battery in that location.

Tue May 07, 2024 3:23 pm

I have a cheap Amazon special 100ah lifepo4 in mine and so far so good. It is hooked up to a renogy 40amp charger on the alternator current (I set the limit
current option to cut the amps in half since the alternator puts out 60amps). I also have 400 watts of solar on the roof which is ample to charge the battery on a sunny day while parked with the fridge running.

The only issue I have is that I need a different charger to combine the solar and alternator. The one I have doesn’t do that, so I just manually connect/disconnect depending on what I am doing. They make these combiner type chargers but they are a little pricey and I’m debating if it’s really worth it since it’s like 2min to change it manually. I could make it seconds if I put in some switches. I suppose it would be nice not to have to remember to do the switching though.

Tue May 07, 2024 4:23 pm

SHBPrincipal wrote: So I did a bit more research and it is possible to mount a lithium battery on its side which may be the option. Not ideal but I want to keep the house battery in that location.

What's not ideal about it? LiFePo batteries are built and designed to do exactly that. Don't bring your old car wisdom to a new car fight ;)

--

captainstick, are you using the LiFePo as the second battery, or only battery?

No Lithium-based battery with a BMS should be run by an alternator without a safety backup/programmable regulator in case the BMS shuts down and lets the alternator run without a load. This can destroy alternators.

Robbie

Tue May 07, 2024 10:20 pm

airschooled wrote: SHBPrincipal wrote:

captainstick, are you using the LiFePo as the second battery, or only battery?

No Lithium-based battery with a BMS should be run by an alternator without a safety backup/programmable regulator in case the BMS shuts down and lets the alternator run without a load. This can destroy alternators.

Robbie

The LiFeP04 is a 2nd battery kept on the drivers side of the engine compartment. I have a regular Lead acid battery on the passenger side for the bus motor. Theoretically the renogy lithium charger keeps them separated but I haven’t really tested that.

Wed May 08, 2024 4:37 am

Hey airschooled.

Perhaps I need to clarify.
- I’m trying to set up a lithium battery as the house battery in the drivers side of the engine compartment, the typical hose battery location. But the lithium (Lifpo) battery is physically too tall to fit under the tire well in that side.

-as mentioned in my last post, I could mount the battery in its side. I feel this is “not ideal” just because, well it’s weird mounting a battery on its side, and I’d have to modify that battery clamp. Doable, and I may end up doing this since lithium batteries can be mounted on their side without consequence. But this is what I feel is “not ideal”..

-in the pics from my last post you will see I reinstalled my failing optima lead acid battery back in that spot Neil I figure this one out.

-yes this system is a dual battery set up with a regular lead acid as the starter battery on the passenger side.