I do not sell them to electric bike review readers. Best to order direct!
http://www.ebikes.ca/product-info/cycle-satiator.html#design-features
Benefits of Partial Charge
One of the key benefits of the Cycle Satiator is its ability to let you easily control the charge level of your battery. It is now well known that most lithium chemistries (with the exception of LiFePO4) can see drastic improvements in calendar and cycle life when they are not held at the nominal full charge voltage of 4.2 V/cell but are charged to a lower voltage instead. That’s how electric car manufacturers are able to 5-8 year battery warranties on cells that usually only test to ~500 cycles.
With most ebike chargers, you have no ability to set the full charge voltage and have to accept topping it up to 4.2 V/cell. This gives the most range on a charge, but if you don’t require the full capacity of your battery on most of your trips then you are unnecessarily reducing the battery life every time you charge it. In many cases that means replacing your ~$1000 lithium battery pack every 1-2 years, when with proper management it could be lasting more like 4-5 years. In fact the further from full charge you go, the more pronounced the life cycle improvements.
With the Charge Simulator we’ve made it really easy to produce profiles that will charge a battery to a given percentage of its full capacity, so you can easily create say 70%, 80%, 90%, and 100% charge curves for your pack, and the Charge Simulator will figure out the required full charge voltage for each. If you have a 20Ah battery, and typical trips only require 12Ah or less, then the 70% charge (to 14Ah) would be fitting most of the time. If you knew you needed just over 16Ah for a longer journey, then you would choose the 90% profile instead, and when you want to get full range from the battery or let the BMS balance the cells, then that is your only occasion to use the 100% profile.
Used in this manner, the Cycle Satiator will pay for itself many times over just by extending the useful life or your expensive lithium battery packs. Nevermind all the other benefits of having a compact, programmable, sealed, high power battery charger with a graphical display screen.
Partial Charge and Cell Balancing
One of the only downsides to partial charging is that many inexpensive battery management system (BMS) circuits will only do active bleed balancing of the cells when they are at or near the full charge voltage of 4.2 V/cell. This means that with partial charge profiles that don’t reach that voltage, the BMS circuit will never be able to rebalance cells if they are drifting apart. Over time you may have less available capacity from the pack as certain cells will hit the low voltage cutoff on discharge well before others.
If this is an issue it can be easily remedied by occasionally (like once every month or two) leaving the pack connected to a 100% charge cycle overnight.
Good quality programmable BMS circuits will usually attempt to balance the cells whenever they see more than a certain voltage spread between the highest and lowest cell in the group, and in that case there is no problem with partial charges. Similarly, good quality
cells rarely drift out of balance in a series string, and can easily handle 100 or more cycles and maintain a perfect voltage matching even if the BMS circuit doesn’t do any active balancing. But if you aren’t sure of the makeup of your battery pack, then the protocol of occasionally giving a 100% top-up is a good bet to ensure both a long cycle life and evenly matched cell voltages.
