Originally Posted by Balsta
I opened up a box with a new Shorai LFX18 for my KTM 990 today. It's my second Shorai and I wanted to make sure it's ok before firing up the bike. My (about 40 US$) voltmeter said 12.9 V out of the box (ambient room temp.). I charged it with Shorai's charger and it "beeped full and ready" at 14.05 volts after less than 10 minutes. When disconnecting the charger, the battery voltage drops to 13.85 after some couple of minutes and then stays there.
I repeated the charging a couple of times and it always tells "full" at between 14.0 and 14.05 volts. The store mode charging stops when my voltmeter indicates 13.0 volts.
I am suspicios on the condition of my new Shorai since 1) the Shorai charger stops at 14.05 volts while the table above in this thread tells 14.34 volts at 100 %. For comparison, my old (almost dead) Shorai reched only 13.3-13.4 volts at full charge with the Shorai charger. Is perhaps the new Shorai already on it's way downhill??!!
Second reason for my suspicion is the very short time it takes to fully charge the battery. I have not tried measuring the voltage of the individual cells as described early in this thread.
Would appreciate any comments and if I should return the battery to the dealer before firing up my KTM.
Tonight the Shorai charger is set on store mode in my garage (a couple of degrees above freezing) and I will repeat the charging to full by tomorrow, to find out if the final voltage differs at lower ambient temperature.
LiFePO4 batteries for motorcycle are made of four cells in series. discharge curve for LiFePO4 are very flat. a specific to LiFePO4 charge typically will charge to 14.6V (fully charged)
battery will then self discharge overnight to about 14.1v for batteries without BMS. it's normal for LiFePO4 batteries with BMS to self discharge to about 13.85V. very little power is contained within 14.6v to 13.85v.
your volt meter sounds like it's off... check with a known to be correct meter like Fluke 87V. it's ok to use cheap meter, but you must verify accuracy first. take any primary lithium battery to an HVAC supply. then ask to see a new Fluke 87V. tell them you are check accuracy of meter. if both meters read same you are good to go. voltage coming of out primary lithium batteries are fairly stable.
reason battery charger is kicking off early sure sounds like your Shorai battery is almost fully charged before sticking charger. notice almost entire discharge ranges about 1/2v difference. an accurate meter is a must!
IMHO LFX18 is way too small for your KTM 990, especially for adventure travel. the only LiFePO4 batteries I can recommend for an adventure bike are Earth-X ETX36 and Shorai LFX36. both have excellent cranking power with ample amp hour reserves.
for bikes only ridden from home base with a fully charged battery everytime. then a smaller battery may be acceptable. still would not recommend LFX18 ... mfg have a tendency to spec battery several sizes too small. LFX18 has a tiny actual amp hour capacity with lower cranking abilities vs larger LiFePO4 batteries from Shorai and Earth-X.
Earth-X batteries delivers cranking amps as claimed. but their amp hour capacities are inflated too. for example ETX24 measures about 6.3 amp hour actual at 1c discharge rate. which will be higher using the much lower discharge rates used by mfg for ratings. but Earth-X ETX 24 managed to excel in delivering sustained 200amp cranking performance. much better than Shorai LFX21 which also put out decent 200 amp cranking performance. but Earth-X ETX24 outperformed Shorai LFX21 by a substantial margin. both have about same actual AH capacity. ignore amp hour ratings by both Shorai and Earth-X, they are no where close to actual amp hours.
see earlier posts in this battery testing thread for exact data.
Shorai LFX 36 after one year with excellent performance, next to Earth-X ETX36 just getting started and doing excellent.