Lithium batteries. - Page 4

slfjas · 08-03-2016, 09:06 AM

In my homebuilt Sprinter conversion, I went with 8 x 195 ah 3.2 volt LiFePo4 batteries, and a Sterling Power battery-to-battery charger. The batteries are from electriccarpartscompany.com, a shop here locally in Salt Lake. So I charge the batteries from the vehicle, but not directly through the alternator. The Sterling b to b charger has a lithium setting. I also got a Sterling Power 2500 w inverter/charger, which I use for "shore power" charging. Our electric needs include frig, maxxfan,a few led lights, an electric hot water kettle, and an induction burner. So far, so good. the Electric Car Parts Company has been great to work with, and best prices around.

John
Salt Lake City

Wrinkledpants · 08-03-2016, 03:03 PM

Quote:

Originally Posted by slfjas

In my homebuilt Sprinter conversion, I went with 8 x 195 ah 3.2 volt LiFePo4 batteries, and a Sterling Power battery-to-battery charger. The batteries are from electriccarpartscompany.com, a shop here locally in Salt Lake. So I charge the batteries from the vehicle, but not directly through the alternator. The Sterling b to b charger has a lithium setting. I also got a Sterling Power 2500 w inverter/charger, which I use for "shore power" charging. Our electric needs include frig, maxxfan,a few led lights, an electric hot water kettle, and an induction burner. So far, so good. the Electric Car Parts Company has been great to work with, and best prices around.

John
Salt Lake City

interesting. How long does it typically take to recharge from the battery? Are you using some kind of battery disconnect?

ShuttlePilot · 08-03-2016, 04:05 PM

If I was to do a system from scratch or a major revamp of my current system I would do what slfjas has. I would just add solar to it as well.

- Eric

allenl · 08-04-2016, 06:57 AM

Quote:

Originally Posted by Wrinkledpants

Are you controlling the electric tape yourself? I'm hoping to avoid having to manually turn on a heating element as I'd like for solar to do the charging during the day (when available), and we won't be in the van during that time. Hence the reason we're thinking of mounting inside the van. Or, outside the van but with forced air blowing heated air from the interior in some type of custom insulated box.

This seems like the perfect time to build an raspberryPI + temp sensor control system for some heat tape. I'd sure like to see the build write-up on this!

Temp sensors:
https://www.adafruit.com/categories/56

slfjas · 08-04-2016, 03:10 PM

I typically don't fully recharge from the battery to battery charger (Li batteies do great at and actually prefer partial charge). I do have a battery managment system (also from the electric car parts company), so there is a disconnect.

Wrinkledpants · 08-08-2016, 06:21 PM

Not sure if this is new, but the SMB website for the Sprinter side is now showing a Lithium option. It's only for the Sprinter at this point, and requires a 2nd alternator.

200 Ah after AGM credit is $3300. You'll need the 2nd alternator. So, roughly $6k all said and done. I'm guessing that includes the lithium regulator, charger, etc.

I'll be chatting with SMB soon and will see if I can get some more details on the kit. We're really hoping to get around 300 Ah of lithium.

Sportsmobile Custom Camper Vans - Systems Info

Wowbagger · 08-08-2016, 07:34 PM

Interesting. I know they were using an all-in-one Lithium battery, about $1K for 12V@100Ah. The system I speced for my rig was about $5k for 24V@300Ah, but with a charge controller and separate cells, but I did leave all the specs and BoM with them if they wanted to copy my work.

ShuttlePilot · 08-08-2016, 08:04 PM

Wowbagger, When you say 300Ah @ 24 volts do you mean 300Ah @ 24 Volts AKA 600Ah @ 12 Volt equivalent. And is that usable 300Ah or are you using about 80% of the 300. Sorry for the overly specific questions but I'm just trying to visualize apples and apples. I'm used to folks using watt hours in my world as the unit of energy storage/consumption, our various systems voltages are all different but must work together.

And assuming the 200 Ah @ 12 volt storage system that Sportsmobile is offering is a usable 200, 3,300 to 6k$ seems steep to me for that amount of storage. That would be the equivalent of two 4D AGM Lead batteries. Which is a nice amount of storage but not crazy storage. Unless the other positive attributes of Li are necessary to you.

This is a fun time to be playing with lithium before it's just the standard.
-Eric

Wowbagger · 08-09-2016, 05:15 AM

Yes, 300Ah@24V is the same energy storage as 600Ah@12V - 7200Wh. That is the total capacity, so I have a usable of 80% of that or 5400Wh. I agree Wh would be more rigorous, but most people on this forum wouldn't immediately understand that.

I agree that 2400Wh for $3300 is a bit much, but you do have to realize using AGM you really would need more like 3 batteries to allow for the 50% max discharge. That's more weight, more volume (really critical on small rigs like these), and also a reduced maximum power due to the higher discharge rates for lithium batteries.

Wrinkledpants · 08-09-2016, 06:39 AM

Quote:

Originally Posted by ShuttlePilot

Wowbagger, When you say 300Ah @ 24 volts do you mean 300Ah @ 24 Volts AKA 600Ah @ 12 Volt equivalent. And is that usable 300Ah or are you using about 80% of the 300. Sorry for the overly specific questions but I'm just trying to visualize apples and apples. I'm used to folks using watt hours in my world as the unit of energy storage/consumption, our various systems voltages are all different but must work together.

And assuming the 200 Ah @ 12 volt storage system that Sportsmobile is offering is a usable 200, 3,300 to 6k$ seems steep to me for that amount of storage. That would be the equivalent of two 4D AGM Lead batteries. Which is a nice amount of storage but not crazy storage. Unless the other positive attributes of Li are necessary to you.

This is a fun time to be playing with lithium before it's just the standard.
-Eric

That's a huge weight savings going with lithium, and for us having an already heavy van, that's the biggest factor for us (lots of water).

And while it's a lot of money up front, it does future-proof us a bit and I gotta believe it'll up the resale quite a bit. In a few years when lithium is more mainstream, I'm guessing AGM vs lithium will be a go/no go for a lot of new owners.

Plus, the $6k installed includes the 2nd alternator. Add in factory high-idle, and you essentially have a built-in generator with a factory warranty. Weight savings, space savings, resale, built-in generator that is more quiet than a regular generator and without the space and maintenance. IMO, it almost seems crazy not to do it for someone that is currently getting their rig built.

With this setup, it means we can have a single solar panel to keep things topped up while running the fridge when off-grid for multiple days (like if we're backpacking and want cold beers to return to). With AGM's, we would have likely needed at least 2 panels because of the slow charge rate after 80% and our lower total Ah capacity. That frees up a lot of roof space for us. If we went with 400 Ah, we would likely skip solar all together and simply run the car for an hour or so every day (which would likely happen anyway). We'll have roof-AC and need at least 1 ski box up there. So, roof real estate is a premium for us.