House Batteries - Inside or Under the Van?

[Scalf77]

I know I can't give you a number that you could equate with doing that. It would be great if people were collecting data.

I believe early on battleborn stated that they supported 5000 cycles, pretty much the same everybody else in their market. The caveat was that this was done in a lab. What does that really mean? I've worked in a few labs, and for the most part it could be wide open, but a common thing would be controlled.
If my goal was to get the most number of cycles it would most likely be very controlled. To there credit the 5000 number has come down to 3000-5000 cycles.

And to be clear my bigger concern hanging the battery underneath the van is heat, not cold. The upper temperature specification is 135°F, so my concern is more targeted at driving down the highway in some of our current summer temperature events. Even lead acid batteries have issues with high temperature, but one could use a DC to DC charger with temperature compensation.

So when asked about lithium batteries I always recommend the first step would be to move inside. This also generally reduces your cable length. So if you have to, I would take into account where you use it the most and how, I certainly would try to insulate the battery if possible. Even if it was 20% off of the 3000 cycle number, you would far exceed your AGM replacement.

Also the BCM being in the battery, will have to endure those same max temperatures.

For the record I may be more heightened about temperature than most because I spent about twenty years using temperature to stress products.

-greg

[Oly11]

Great info from both of you. Really appreciate it

[ShuttlePilot]

When I decided to change to BB lithium, the largest factor in my decision to install them inside was that I was unwilling to hang 1600$ of batteries under the van on the frame rail. Cold temperature was only one factor but also water, salt water/mag C from the Colorado Dept Transportation, and as mentioned high temperature. My 4D lead battery had a temp monitor on it and would regularly see over 125* in the summer when parked over asphalt that was preheated in full sun. I realize I could have built a sealed box to put them in but, no, wasn't going to do that. In my case there really wasn't any down side to where I mounted them. Over the lifespan of the batteries, under the goucho is the most climate controlled spot on my ship.

As I say that here is a photo of last winters coldest day parked in my driveway completely making me eat my words. That was in F not C BTW. At that temperature the BMS had turned the batteries off to charge and discharge. Every extreme effects cycle life and capacity to every battery so I believe it is wise to at least try to limit those events with design or usage as much as possible. I don't believe Battleborn is leading anyone astray by saying you can use their batteries in cold or hot temperatures, it will work with some compromises, however, know that they are in the business of selling batteries and don't want people to have reservations on using theirs.

- Eric

[bigriver]

Originally Posted by Scalf77

I know I can't give you a number that you could equate with doing that. It would be great if people were collecting data. -greg

We just finished a project that will allow us to provide some empirical data in the future as we just replaced two 4D AGM house batteries (420 AH - 240 lbs.) with a single 200 AH - 60 lb. lithium bat. Over 18 yrs we've had two sets of 4D house batteries - the first set lasting 11 years (Lifeline) and the second lasting 7 (Full River). In this time we've spent over 1300 nights in the van, almost all boondocking, so we have a good idea of how those batteries performed. In 2020, with Scalf's assistance, we upgraded to a Kisea DMT1250 DC to DC charger and a Balmer battery monitor

We have zero room inside the van for the battery so the priority was to find a lithium that had a 4D form factor to mount on the existing under-side-door bracket and wiring. The only 4D LiFePO I could find was the 200 AH Renogy RBT200. I generally stopped buying the inexpensive stuff about 20 years ago but decided to take a chance with the Renogy since it checked all the other boxes for the project and was about the same $ as two more Lifeline AGM. I originally intended to buy a BattleBorn and then was very tempted by the Lithionics suggested in a previous post but there was no BB that would fit and the big bad boy Lithionics $4000+ tag ended that happy thought.

Dropping both batteries was a battle as any who've done it in their driveway can attest, but a couple hrs later they were both out. I then come to find that apparently, to some manufacturers, the 4D form factor is not an exact measurement as the Renogy was almost an inch deeper than the existing mounting bracket. So out come the sawzall and grinder and accommodations were made. Too bad y'all aren't going to get to see it because it was beautiful work I assure you .

So - here's my take on it: I replaced 240# of AGMs with 60# of lithium for effectively the same price, capacity and potentially a much longer life. The downside is it's an inexpensive battery mounted outside the van. I figure if we get 3-5 yrs out of it I can replace with something much better for the same, or less $ as bat tech improves. In the mean time we'll be guinea pigs for the lithium-outside-the-van debate. As a data point - we are not skiers so are generally only traveling through cold to get to warm.

Oh - one thing I really like is the built in Bluetooth connection to the BMS. They are starting to be pretty common and seems like a viable replacement to the stand alone bat monitor.

[natesmithslo]

Curious as to where you mounted your new lithium batteries inside. Mine are located in the same spot under the barn doors.