Van Specialties - Convert old AGM underbody tray to Lithium

Outlookela

Member
In 2016 Van Specialties installed 448 amp hours of AGM batteries in an underbody tray charged by my alternator, shore power and solar (I added solar later later).


I expect to replace my batteries maybe 2 years from now, possibly sooner and possibly with Lithium. In 2016 the technology was too bleeding edge. Four years later am wondering who has updated a Van Specialties style underbody tray to Lithium?

Am thinking I might just want to go back there and get a drop in solution if one has become commonplace and well tested. I'm aware of some of the Lithium issues - extra draw on alternator, charge while freezing issue etc. Prepared to wait if the technology still seems buggy or if I have to change a lot of other things - wiring, shore power charger, alternator relay, solar controller etc. But it would be nice to drop a few pounds rather than buy in to another cycle of AGM's.

Would like to hear:
1. Are we there yet and is it almost a no-brainer?
2. is it a wait for a bit longer type of thing, too many bugs yet?
3. is it just too much money getting the system re-appointed, get new AGM's and stay with your AGM set up that works?
Thanks!
 

gltrimble

Well-known member
Check out my build thread where I replaced similar batteries, Fullriver AGM, with Lion Safari lithium. The lithium batteries are smaller dimensionally than the Fullriver batteries which allowed me to wrap them with battery heaters and insulation for cold weather use. The only other changes were to reprogram my MPPT and my Balmar voltage regulator for lithium.

AC5E134D-2965-45F3-8261-75A672A8CB53.jpeg
 

IPT

Member
Check out my build thread where I replaced similar batteries, Fullriver AGM, with Lion Safari lithium. The lithium batteries are smaller dimensionally than the Fullriver batteries which allowed me to wrap them with battery heaters and insulation for cold weather use.
How does that work exactly? What if it was Alaska with darn cold temps (-20F on occasion but usually single + digits and up)? Is there a temperature monitoring system that allows the batteries to only be charged when optimal temps (via the heater) are achieved? Is the battery heater always running or only when the van is on or you turn it on?
 

gltrimble

Well-known member
I've done a couple of searches for your build thread above. Could you post a link?
My build thread link should always show at the bottom of each of my posts. If not, check your settings. Here is a the link.

 

gltrimble

Well-known member
How does that work exactly? What if it was Alaska with darn cold temps (-20F on occasion but usually single + digits and up)? Is there a temperature monitoring system that allows the batteries to only be charged when optimal temps (via the heater) are achieved? Is the battery heater always running or only when the van is on or you turn it on?
If I lived in a cold climate year round I would likely have second thoughts about using lithium batteries. I initially went with AGM batteries because of my cold weather concerns. I like to visit ski resorts for weeks at a time but most of my van use occurs in above freezing weather in the western US. My lithium batteries will reportedly provide power down to -4F but will only accept a charge above freezing. The 80 watt battery heaters I installed are controlled by a pair of Inkbird temperature controllers. I actually have not completed the full install of the controllers but my plan is to program both of them to activate the heaters at about 40F. Assuming a typical overnight temperature of 10-20F here in the mountains of the western US, it does not take a lot of energy to keep the batteries at 40F. I believe Hein is offering something similar for heating exterior mounted lithium batteries. I have a separate circuit breaker I activate in cold weather that keeps batteries, water lines, water heater, and my water tank from freezing. Many users install the lithium batteries inside the van but you still need a heating system to maintain the battery temperature in an unattended van. Also, the BMS will prevent any charging at or below freezing.
 

HarryN

Well-known member
How does that work exactly? What if it was Alaska with darn cold temps (-20F on occasion but usually single + digits and up)? Is there a temperature monitoring system that allows the batteries to only be charged when optimal temps (via the heater) are achieved? Is the battery heater always running or only when the van is on or you turn it on?
Alaska is not really an ideal location for Li batteries.

For that region, something like a lifeline AGM or similar quality brand is a better option.

When it is (-20F) that is not the time to be wondering if software will shut off a battery function.

Those types of conditions are why I use 24 and 48 volt battery packs and a DC - DC converter for the final 13 volt regulated output in vans.
 
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Midwestdrifter

Engineer In Residence
Obviously it depends on your needs, but my insulated battery box should be good down to about -20F. Though at the temperature the heating pad (65w) will run continuously to keep the pack above 50F. Double insulation would lower that to -35F.

If you don't mind waiting 2-6 hours, you can let the pack cool down, and when needed, flip a switch to warm it to charging temperatures. Its not rocket science, but does require more design considerations. Unlike lead, LFP packs won't degrade for continuous partial charge usage (lack of solar in the winter). And they can charge pretty quick from an alternator if you need a boost in the middle of the night.
 

Outlookela

Member
Thanks everyone for the comments - It seems like the swap still requires a fair amount of knowledge, (that I don't have at this time) but can be done if you know what your are doing. Sound like we are at number 2 below in the original thread questions.

Would like to hear:
1. Are we there yet and is it almost a no-brainer?
2. is it a wait for a bit longer type of thing, too many bugs yet?
3. is it just too much money getting the system re-appointed, get new AGM's and stay with your AGM set up that works?

Thanks!
 

marklg

Well-known member
Thanks everyone for the comments - It seems like the swap still requires a fair amount of knowledge, (that I don't have at this time) but can be done if you know what your are doing. Sound like we are at number 2 below in the original thread questions.

Would like to hear:
1. Are we there yet and is it almost a no-brainer?
2. is it a wait for a bit longer type of thing, too many bugs yet?
3. is it just too much money getting the system re-appointed, get new AGM's and stay with your AGM set up that works?

Thanks!
My opinion is #2, just because you are in Alaska where the cold temperatures are very significant. If you do go with Lithiums, since you don't have a lot of knowledge, I would suggest you go with batteries that have built in heating systems (ReLiOn, Lifeblue, maybe others) and are designed and sold as cold weather batteries. That way, if something goes wrong, you won't have a battery company tell you that your self made heating system is the culprit and refuse to pay on the warranty. Same issue if they don't work and you are stuck. You will be less likely to get into a finger pointing exercise. You still have to insulate them, but hopefully the battery company can suggest what they need.

I am in Arizona and for me the decision was #0, fully a no-brainer. We don't go where it is cold.

Regards,

Mark
 
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Midwestdrifter

Engineer In Residence
The current crop of drop-ins appear to be reliable when used within the limits published. Prices are fairly competitive at 7-10$ per 12v AH.

The reason to stay with lead, would be lower lifetime cost for certain applications, and deep winter operation without heating. For some folks, their usage is light enough, that even a lithium battery would age out before it cycles out. So if inexpensive flooded lead batteries are lasting you 5+ years, and they aren't negatively impacting your usage, consider staying with lead.

If your batteries are not lasting more than 2 years, or you have significant performance issues, LFP replacements may be worthwhile from a cost and usage perspective.
 

IPT

Member
My opinion is #2, just because you are in Alaska where the cold temperatures are very significant. If you do go with Lithiums, since you don't have a lot of knowledge, I would suggest you go with batteries that have built in heating systems (ReLiOn, Lifeblue, maybe others) and are designed and sold as cold weather batteries.

Regards,

Mark
I think the OP is from BC but I'm sure it's cold there too.

I didn't even know there were options such as the cold weather Lithium batteries (with some sort of self regulation). That might sway me because I am doing an inital setup.

OP I'd probably opt for #2. Particularly because you're already setup with the other system. It's just an expense for swapping in new batteries and you're rolling again. Now if there was weight or space considerations that are hindering you I might think different, but I'm sure in 3-5 years the lithium game will be: A-more affordable, and B-more stable and streamlined.
 
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Midwestdrifter

Engineer In Residence
LFP batteries can discharge when cold (below about 40F). But cannot charge. So most drop ins will disconnect internally if you try to charge them cold. Not ideal, but not going to destroy anything.

Some of the "low temp" LFP batteries use internally heating elements. When sufficient charge power is applied, and the battery is cold, it shunts the charge power to the heating elements until the cells are warm enough to accept current.
 

Outlookela

Member
What it is coming down to for me is to replace my agm’s. I don’t have to worry that something g won’t work properly or Be unsafe. I just want things to be easy and low risk - financially and time wise too.
 

hein

Van Guru
We have placed Battleborn batteries in our enclosed under-vehicle boxes. We insulate with Thinsulate AU4002-5. We put a 12V heating pad underneath the batteries with a temperature probe/controller. A Katts 120V 250 watt silicon heating pad could also be stuck to the outside of the box and used when AC power is available. Results have been good. The benefit of our boxes is that they more completely enclose the batteries and protect them from rock hits. Especially on the 4x4s where folks are going off-road.

All the best,
Hein


 
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