Lithium - Charging
Picked up a couple 12v 100amp-hr Lithium batteries off amazon ($150 each delivered including bluetooth monitoring). My charger has a lithium setting and I have 240w of solar. I've had them installe...
Forum Discussion
While I am not an expert at the care and feeding of batteries, Will Prowse is, and he points out that LiFePO4 batteries have a BMS that requires them to charge to 100% in order to balance the cells. This is essential at least with some frequency lest the cells become unbalanced. One can argue that cycling them between 20% and 80% will give you the longest life, the fact that even the roughest use is likely to have them last 10 or more years, you are going to get your money's worth out of them. Will Prowse says cycle them between 5% and 100% all you want.
The battery chemistry in you phone definitely does not like being charged to 100%, but the chemistry of those batteries in your camper is totally different.
the issue I think is when he is at home and it is sitting in the driveway, if you look at what will said it was more that normally cycling between 0ish and 100% isn't an issue as the batteries will most likely age out before you run out of cycles.
the issue is holding them at 100% for long periods, think storage, is bad and will reduce cycle life even more than the operating range. although not as bad as leaving it sit at 0% for long periods and this is a easily preventable issue by just dropping the voltage while it is in the driveway or shutting the battery off at a reduced charge if you don't need to run a battery at home.
That's closer...we spend 6-8 months in the summer in the RV. 90% of the time we are on shore power.
While on shore power, there is nothing to gain by keeping them constantly at 100%. If we will be boondocking, it's easy to flip the switch the night before and take them to 100%.
This does presume taking them to 100% occasionally to balance them.... currently the cells are within 0.001v per the BMS.
it would almost be best if you could get an adjustable voltage converter where you could just put it on 13.4V when you are on shore power. to me the perfect Li converter hasn't been made yet. I would want a 2 stage with a button you could push for a storage mode that stays there until it is taken out of storage mode. so it would be a 14.6V that reduces to 13.6 for the float, then if you push the button you can enter a 13.1V storage. then when you are hooked up to share power all you have to do is push the button for a 13.1V constant output. you can run everything and your battery voltage will be in the long term storage range
