I should mention this. The reason to stay away from batteries with bms in a real dirt or dual sport application. If the battery is just on the verge of being able to start the bike. Lets say 9-10v for lead acid. A comparable lithium battery with bms will not truy to start.....at all! You will likely be stranded. A good chance of this happening if you leave the key on or use a electric acessory which runs the lith. Battery down it will simply do nothing. Lead acid may very well crank the bike over and get you started. I build many lithium batteries for my bikes. Http://www.pacificebike.com that said when around town commuting I use lithium. On a long trip far from home where I need reliability, believe it or not I throw a new lead acid in. I have been stranded by several s based powersports batteries in the past. Now I build my own sonic welded packs with a123 cells. These have no bms and will simply damage themselves before they would not supply the amperage. The downside is any problem with the stator or short in wiring can be VERY bad. Overcharging lithium cells can cause them to burst and vent all kinds of horrible sometimes flammable substances. Ever see a lithium battery burn? I am a huge advocate of lithium batteries but not in a powersports application. My $0.02
At 9 or10V most ecu driven bikes won't start anyway unless you can push them enough to get the alternator to produce 12v+. Even my old race VTR250 which I had the most trouble with batteries , would not run the ECU at under 11V at all. Just drew too much current. modern ECU's may require less current and in fact voltage of course. Quite a reasonable possibility as most electronics now runs at very small voltages and the coils are at the spark plugs. I havent had the need to check ( touch wood) Haven't seen a lithium burn ( though I know they do) , but have seen a Pb battery explode from to high a charging rate. Both would be messy. One acid, one Alkali. I have never had a lithium fail, bar one which had a faulty cell at new, but had MANY ( read dozens) of Pb batteries fail in cars and bikes. Modern Pb batteries have a very short life compared to what they used to have ( when I wert yung they lasted forever...well 4 or 6 years, now 2 or 3 is a good one). That may be do with living in the tropics though. Calcium batteries many be better. I am using one in the 4wd now as they advertise as longer life and able to handlle deeper cycling without damage. It's been good so far. I have done heaps of long trips with the Shorai with no problems so far on any bike. A lithium is so light you could quite easily take a spare an not even notice the weight ( I did for a while). Sally's bike has a spare with an isolator so we can use it camping. Combined weight of both ( overcapacity) batteries and isolator is still way less than a Pb.
Calcium, i think you are referring to batteries where the plates are coated. This is usually found in military batteries. They have extended shelf life when NOT in use. This helps the plates from becoming sulfated. When in use I believe they offer 0 advantage over standard lead acid. Modern lead acid batteries have two problems. Low quality materials used. Modern manufacturing has made them much more compact thus easier for the plates to touch or get damaged from vibration. Old batteries were larger, non sealed, so some new distilled water and a bit of burst current and theyvwill work for a few more years .
Am I reading this right, you want people to stay away from lithium batteries with management systems?
Yes and no. It is up to you to make the decision. There are cons and pros to both. Only lithium batteries I see that catch fire are from improper charging. A bms will usually stop this. A BMS is also one more computer to go on the fritz and can strand you. This is why I use lifepo4 a123 cells sonic welded. No bms, so unless my stator or regulator fries, or the battery shorts. All is well. It behaves like lead acid in the respect that it will provide current even if voltage is not in optimal range. Hope that clears up what I am trying to say. It is hard to write on this "smartphone:.
I certainly cannot speak for all batteries, but the Earthx is a little different. It is good down to around 8 volts, where as a Shorai bricks at anything below 10.6. And it's electronics are high quality and made in the US. Even if you drop down below the management cut off, the battery will recover some over time and possibly start in an emergency.
Honestly not hard at all. Approach it as a machine, or anything mechanical. Generally there are two types of cells used. Each is 3.7v nominal or 4.2v charged. There are other voltage cells but we only use these normally. The two basic types (not chemistries) that are most common are: Polymer (google images) (squishy pouch with tabs out the top) And the cylindrical type 18650 or 26650 (think AA battery-sh sized and shape) The cylindrical cells can come in button top (again think AA batteries) or the standard terminals. The cylindrical cells cannot be soldered like you would normally. They use ultrasonic welders, kind of like this picture: This allows you to attach the tabs to the batteries without heating them up, also solder will not stick to them very well even if you got it extremely hot. Some cells are stated to be self balancing but they are not. They just have the same internal resistance when produced, thus they should all stay evenly (they do not usually but it works fine for quite some time if care is taken). So simply put, for polymer, you align all the pouches to how you want to attach them. This is basic, if you want to parallel them or series them you do so. Fold the tabs over eachother and solder them quickly without overheating. You then wrap all the cells in tape, and then heavy duty plastic shrink wrap (like heat shrink for wires). Then to properly balance and charge the cells you must take a BMS board configured for your voltage and output current (this is adjustable via changing the resistance of the shunt if needed) Usually I purchase a bms for my application that needs no adjustment. OR re-use the original if it is a simple battery replacement/update. You must wire the bms to each individual or group of parallel cells for charging. This is the units specific purpose. It will stop charging individual cells then they reach 4.2v or the specified cut off, and then ATTEMPT to bring any other cell that is below this up to 4.2v. If ONE cell is down to 3.7 volts, the battery will turn off early as the total pack voltage is lower than specified. Here is a picture of someone who built their own pack. Disclaimer: I am not a engineer, I am a technician/mechanic. There is a TON more information needed to safely build packs and it can be very dangerous. That said, in 5 years dealing with a MINIMUM pack voltage of 24-36V I have NEVER seen a battery catch fire with a bms. I have seen several packs vent gas when improperly charged, as the cells reach around 100psi they burst. This is why lithium batteries have a general bad rap of being dangerous. If the bms fails, AND the charger does not shut off the charger will keep charging individual cells and they will get hot and burst, if the heat/pressure is high enough it vents gas that can ignite. (never seen that one, sounds like fun!) Also there are MANY different types of chemistry used in the cells. Lifepo4 is currently regarded as safest and "best" with long life and high current output. I also use Limn02 which is the cheapest and most common used in electric bicycles. But hopefully that gives you insight on the basic construction. Thanks google for the images, as im sitting in bed and not going downstairs to take pictures of batteries at 9pm
Note to self: Buy ultrasonic welder. I foresee me playing around with this, not for motorcycles, but for other applications. You'd be amazed at how much of the government's money I've spent on batteries for uninterrupted power supplies. This could prove to be a valuable skill to have. Save Uncle Sam some money and get the parts I need faster. Win-win.
I´ve used different makes on my bikes for over two years now and have never had any probs. They´ve always recuperated well when having been drained. They show hardly any willingness when it gets really cold ... but then they seem to pull in at the last moment. Don´t think I´d ever go back to lead batteries.
I run heated grips and a heated vest. I do have everything on a fuse block activated by a relay when the key is off/on. My voltmeter tells me that I am down about two volts when running the gear. So, the power diverted for these items isn't available for charging. Do these batteries cope well with this sort of drain on them?
The drain should be fine, but if you are down 2v are you down to 12.xxV or are you holding above 12.9V. What could happen is that the battery never gets to be fully charged while the load is on it. So you would need some riding time with the load removed to allow it to recuperate. Or put it on a tender/charger when you get to your destination? I would try to find a way to be more efficient and lower the load. Sometimes the headlight can be the difference between charge/discharge.
One thing I was taught over 30 years ago was when it is below freezing turn the headlights on for a couple of minutes. Turn them off and then crank the engine. Have you ever noticed when you turn the key it will crank slow and if your car does not start you turn it again, the engine cranks faster and starts. All batteries loose capacity when cold.
The newer fuel injected bikes use a fuel pump that runs constantly, drawing close to 3 ampre. You need only to turn the key on and charge the fuel system. A 3 amp draw on a 12Ah battery is significant and will certainly heat the battery. If you do choose to run Shorai batteries, it would be wise to also purchase their battery management system which will allow you to keep it at 80% charge. My Shorai lasted 8 months without the bms, at 12 months, it was completely bricked.
Do any of the new lithium batteries have a special plug to enable the cells to be charged individually? If not, how does `balanced´ charging work? (My two batteries only have the standard two connectors + and -)
They either have a circuit (bms) prewired you put power into it via + - and it controls the charge for each individual cell. Or in the case of high end cylindrical cell batteries, they have the same internal resistance and charge from the factory and do not "draw" on one another. "Self balancing". This works......for awhile. Honestly at the price point it becomes "whats my time worth" opening the battery to gain access to each cell hook up a power supply (might get a decent one for around 200$) spend an entire day babysitting and charging the cells evenly. At the price these batteries are not worth working on. Charge your battery with a power supply and check where it no longer accepts current. If this is below the full charge voltage of the battery then likely it has a low cell or two.
Shorai battery update: No problem starting my bike this morning. It was high teens last night and snowing. This morning it was about 22 degrees. The bike was outside and under a cover all night. I turned on the headlight and waited about 30 seconds and the bike turned over after about 3 cycles. I am happy with these results so far.
