Hypothetical Winter Camping Electrical Limits
Hi, I used to have a very old tow-behind trailer that I used during the winter in Colorado; 2 batteries, 2 propane tanks. Since the furnace had no fan it was easy to be out a week, dry. Now I did...
Forum Discussion
Bill
Chris of Technomadia did write-up of success and failures after 3.5 years of lithium battery usage.
He expressed their failures quite nicely: primarily in the realms of not paying attention to the temperature limits of the cells and maintaining upper voltage limits of the individual cells. They used a Voltage Management System (VMS) instead of a Battery Management System (BMS). We can watch our BMS monitor as it balances all 16 cells (48 V nominal system) by the second.
Individual cells should not go above 3.4 V (long winded discussions on this on Aussie and Cruiser forums - up to 4000 responses on one thread).Chris notes "...The balance boards 3.5 years ago did not trigger a balance load until the cell voltage reached 3.7V. This is actually slightly above the over-voltage cutoff on the EMS.." 3.7 V is 0.3 V over recommended cutoff and result in quite a bit of cell degradation.
As you note, battery technology should develop over the next few years and hopefully prices will drop. The theoretical work was apparently done in the US but the Chinese are doing the engineering since their internal usage of solar and energy storage is greater than that of the rest of the world.
Reed and Elaine
Chris of Technomadia did write-up of success and failures after 3.5 years of lithium battery usage.
He expressed their failures quite nicely: primarily in the realms of not paying attention to the temperature limits of the cells and maintaining upper voltage limits of the individual cells. They used a Voltage Management System (VMS) instead of a Battery Management System (BMS). We can watch our BMS monitor as it balances all 16 cells (48 V nominal system) by the second.
Individual cells should not go above 3.4 V (long winded discussions on this on Aussie and Cruiser forums - up to 4000 responses on one thread).Chris notes "...The balance boards 3.5 years ago did not trigger a balance load until the cell voltage reached 3.7V. This is actually slightly above the over-voltage cutoff on the EMS.." 3.7 V is 0.3 V over recommended cutoff and result in quite a bit of cell degradation.
As you note, battery technology should develop over the next few years and hopefully prices will drop. The theoretical work was apparently done in the US but the Chinese are doing the engineering since their internal usage of solar and energy storage is greater than that of the rest of the world.
Reed and Elaine
