LiFePO4 with Yttrium to be exact. I picked up my crate today from my buddys shop where it was delivered. It had been sitting in Ft. Worth since late last week with the ice storm.
Just had time to pop the top and take a peek and yes there are 4 cells which will be 1000 amp hours when installed. Tomorrow I'll bust open the crate and take a few pictures then check the voltages and start putting the cells together. I expect it to take a week or two to get everything installed and working together. And I'll document the install here with pictures and prices. Hopefully the 1000 amp hour capacity will be a bit more than 6 8D's and should recharge much quicker.
I am very interested in how this turns out. What was the cost of the package?
Clarke and Elaine Hockwald
1982 Newell Classic, 36', 6V92 TA
2001 VW Beetle Turbo
Cannondale Tandem
Cannondale Bad Boy
Haibike SDURO MTB http://whatsnewell.blogspot.com
Here they are unboxed as they say on youtube. The total size is 20.5" wide x 22" deep x 14" high and each cell weighs 92#. The BMS (battery management system) is in a real nice pvc box that is too large for where I want to install it in the compartment so I'll pull it apart and mount the shut-off contactor and a couple other components on the wall of the compartment. I'll put the BMS circuit board in a small pvc box and mount that on the wall. The 4 cells will be connected with copper straps. Each cell is 3 volts nominal so together will produce 12 volts. Actual voltage stays pretty constant at about 13.8 volts even with large amp draws.
The total cost with shipping for the 4 cells + the BMS and connectors was $3247.84 from Balqon.com I will still need to buy a SOC (state of charge meter) and these run anywhere from $70 to a couple hundred depending if you want wifi capabilities so you can check the batteries on your phone. The voltage stays pretty constant until they are almost fully discharged. Hence the need for the BMS that shuts down the batteries before they are damaged. So you can't go by the voltage like you can with lead acids or agms.
I might have to change the alternator regulator to a Balmar MC-614 which has a temperature sensor. The lithiums when low can accept such a large charge it is possible to burn up your alternator. The Balmar de-rates the alternator output based on the alternator temperature. This is about $300.
So the total cost will probably be around $3800-4000. About the same as a set of agms!
But I probably won't get much done until next week. Gotta take care of the new grandkid!
Got a bit more work done yesterday. The enclosure housing the BMS system was way too big to fit in the compartment so I took everything out of it and mounted just the control board in a small plastic enclosure. The contactor which shuts off the batteries if they reach a high voltage of about 15 volts or low voltage of 11.2 I mounted on the wall so the positive wire from the batteries will connect to that. Then I mounted a piece of aluminum angle to the floor of the compartment to mount the BMS switch, reset button, and alarm buzzer. The buzzer will alarm at about 1/2 volt before the BMS shuts down the battery. I also ordered a Victron BMV-600S battery monitor to mount on the panel above the microwave. This will give me a state of charge of the batteries and I'll have an alarm beeper on it set a couple tenths of a volt higher than the BMS buzzer. My plans are to charge the batteries then leave the charger off. Then monitor the Victron and charge when that beeper comes on only charging until it switches to float the shut it off. This is the preferred usage profile that the live aboard boat guys are using and seems to work good for them. I figure my battery usage will be similar. It seems there is no need to float charge lithiums. And there is no need to fully charge them. You can partially charge them with no problem. So it'll take a bit of an adjustment but should be easier to maintain these.
I mounted 2x2" heavy aluminum angle to the floor and the batteries will sit in this square. I also have 2 pieces of 1/8" aluminum sheet cut out for the battery sides. I'll use 5/16" threaded rods to attach these. This will hold the 4 cells securely. 400# of batteries should not move. Considering Newell doesn't use tie-downs for the 8D's this should work.
I got the aluminum at a small shop that builds crawfishing boats. He had some drop-offs that I got for $20. Yeah, yeah, I know Tom would have only paid $18. I'm cheap but don't squeak quite as much as him
I am also balancing the cells. I need to get each cell voltage as close to each other as possible. They range from 3.446 to 3.481 so my choices are to either buy a voltage adjustable charger to bring the low cells up to 3.481 or use a resistor to bring the high cells down to 3.446. So being cheap, I took an old spotlight and connected it to each cell while I monitor the voltage. It's working great.
That's all for today, and probably this week. Got a few other things planned.
