199 replies to this topic

[billharr]

This is of great interest to me as well. Looking forward to seeing some pictures of your installation.

+ 1. Have two batteries now but at some future date I will need new batteries. Hope you have a full report by then on how the battery works.

[DrJ]

+2
I've wanted to use lithium ion batteries before but the cost and setup were too much for me. Please post some pictures and links to your battery supplier. I had a hard time finding much.

[cdbrow1]

I am using batteries from Stark power - http://www.starkpower.com/

 

I can't speak to their quality or reliability yet. They have a good rep in the motorcycle world. 

[cdbrow1]

I have also hear good things about 

 

Braille -  https://www.braillebattery.com/  (too pricey for me)

 

and 

 

Lithionics - 

 

http://www.lithionicsbattery.com/

[enelson]

I believe the FWC battery space is not specifically vented. The battery is accessible from inside the camper and not outside.  That being said it is still down low in the camper and close to the bed of the truck (which tends to be cold). I was aware of the cold weather charging issue with LiFePo batteries, but I think it is only an issue below freezing temps. I think that is not going to be a problem in that location. I had not thought about using my IR thermometer to check on the battery, but that is a great idea and I will make it so. 

 

We've been winter camping up in the high country.  This is the only reason I am concerned with the battery temperature.  Anything above 25 degrees F shouldn't be an issue for LiFePo batteries.  Its OK to discharge them at any acceptable discharge rate in the cold just not charge above capacity divided by thirty.  I have more than enough capacity to just pull the fuse from the truck supplied current for a weekend trip if I want to be extra careful.  These batteries are expensive so taking extra care is probably the way to go.  So far, I'd buy them again without a doubt.  I have to remember to put the IR thermometer in the camper.  The snow is looking a bit iffy this weekend though.

[cdbrow1]

We've been winter camping up in the high country.  This is the only reason I am concerned with the battery temperature.  Anything above 25 degrees F shouldn't be an issue for LiFePo batteries.  Its OK to discharge them at any acceptable discharge rate in the cold just not charge above capacity divided by thirty.  I have more than enough capacity to just pull the fuse from the truck supplied current for a weekend trip if I want to be extra careful.  These batteries are expensive so taking extra care is probably the way to go.  So far, I'd buy them again without a doubt.  I have to remember to put the IR thermometer in the camper.  The snow is looking a bit iffy this weekend though.

 

I am hoping that it will never get to 25F inside my camper - put it is worth watching. I assume charging/discharging them should generate internal heating. I know my Chevy Volt (which uses different chemistry Lithium Ion batteries) uses a separate heating and cooling system for the battery pack - as well as sensors in each cell for temp. Of course that pack (weighs about 400 lbs) is moving a lot more electrons around then a deep cycle battery. 

 

The Stark power BMS does monitor cell temperature so I ASSUME it would disconnect if the battery or cell was too cold to safely charge - but I think I will ask them to confirm that. They claim an operating temp of -22 to 140 F, however operating is not the same as charging. 

[Advmoto18]

I'm just down the road from NASCAR's engine town (Mooresville).

 

Likewise, I'm interested how this works for you. 

 

Stark LiFePO chargers aren't terribly expensive when you consdier how much the 100Ah battery costs!

[enelson]

I am hoping that it will never get to 25F inside my camper - put it is worth watching. I assume charging/discharging them should generate internal heating. I know my Chevy Volt (which uses different chemistry Lithium Ion batteries) uses a separate heating and cooling system for the battery pack - as well as sensors in each cell for temp. Of course that pack (weighs about 400 lbs) is moving a lot more electrons around then a deep cycle battery. 

 

The Stark power BMS does monitor cell temperature so I ASSUME it would disconnect if the battery or cell was too cold to safely charge - but I think I will ask them to confirm that. They claim an operating temp of -22 to 140 F, however operating is not the same as charging. 

 

Yes, they may disconnect charging at low temperatures.  The Nissan Leaf disables the regenerative braking in cold weather for the same reason even though they are Lithium Cobalt instead of LiFePo.  With my Electrodacus LiFePo BMS board I could program the input FET to  open at cold temperatures.  The BMS already has a temperature sensor and is mounted with the batteries.  I don't have time to do the project at the moment!

[cdbrow1]

If your compartment is vented you can seal it off from the outside air.  LiFePo batteries like room temperature best and is important if you want to charge at a higher current.  I charge at low current on cold mornings since the solar isn't doing much of anything then and I'm only getting 6A out of the trailer wiring aux battery power.  I need to bring my IR thermometer to measure the temperature of the batteries during cold morning camping.

 

I will be charging off the FWC camper connection, which is only 10 gauge wire. It won't be passing too many amps down that path. Otherwise would be off line power or the generator via the IOTA DLS which would charge at higher amperage, but most likely during warmer hours. 

 

I am not doing solar - yet. I will probably be adding 100-180 watts of flexable panels on the roof down the road, but only if I can find a solar charger that will work within the confines of the charging profile I need. 

 

 

Stark and the other vendors I have spoken with have all advised against "float" charging - they say charge the battery to 14.6 volts and then take it off the charger until it need another charge.  Have you addressed this? 

[cdbrow1]

Well the deed is done. Fed ex dropped the battery off this afternoon and it took about 15 minutes to disconect the electrical, pull the old battery and drop the new one in place. The only required change was to move a small piece of wood trim (two screws) in the battery compartment. The new battery reads as 'full' on the FWC gauge, however that is just a voltage gauge and is not accurate for the new battery. I am actually not sure how I will keep track of the state of charge since there is not a system that I know that will work. It ran a short test with my inverter and 650 watt microwave and it seemed to hold up fine. I did get an overload alarm, but it ran for the full 2 minutes I set it for. All the electrics in the camper seem to work fine.

Since I got the flu bug I don't think I am going to get a text I this weekend and next weekend is already shot. As soon as I can I will spend a night out in the sticks and see what happens.

I will post photos later this evening.