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Do SLA / AGM Batteries Need Cycling

Discussion in 'Technical and Troubleshooting Torque' started by xXx, Sep 10, 2012.

  1. Hi guys,

    Just wondering if SLA or AGM motorbike batteries need cycling to make them last longer. Discharge to like 50% and then Recharge? or is a waste of time?

    I know if they are discharged too much they get damaged.

    During winter I don't ride that much but charge my battery every 2 weeks to top it up.

    Thanks in advance.
  2. No, in fact this will reduce their life. Lead Acid batteries (this includes gel cell and AGM) are happiest when kept full or almost full.

    Consider a float charger (aka trickle charger) or a 3 stage charger to maintain your battery. It will last longer when on a constant charge compared to just boost charging it every 2 weeks.

    * Some AGM technologies can be optimised by an occasional mild discharge but in reality and normal use, no difference.

    Wokwon's summary of battery chemistry (from memory so YMMV):
    Nickel Cadmium (NiCd): Memory effect, discharge completely before recharge; do not charge too fast. Old technology, not really around anymore.

    Nickel Metal Hydride (NiMh): Very small memory effect, almost negligible. Charge as fast as you want but watch the temperature and slow/stop charging when they get warm.

    Lead Acid (wet vented cell): Keep full, ideally at 2.3 volts per cell. Try not to discharge or charge faster than C/20. (C is capacity in Amp Hours). Avoid discharging beyond 50%.

    Lead Acid (not vented i.e. Gel Cell): Keep full, ideally at 2.3 volts per cell. Fast charging or high voltage charging will pop the emergency vent so keep charging current down. Avoid discharging beyond 50%

    Lead Acid Calcium: Same as Gel Cells above but these tend to last longer in terms of overall cycles.

    Lead Acid (AGM): Same as Gel Cells but can take more vibration, work in any orientation and can tolerate faster charging and deeper discharges. Still try to avoid discharging beyond 50% although they'll handle it better than a flooded cell.

    Lead Acid (Deep Cycle): Slow charge, slow discharge. These gas like a mofo when hit hard.

    Lithium Ion: They're on a timer. Once it's manufactured it'll last about 18 months regardless of how often you charge or discharge it. Will last longer if charged to 40-50 and kept in the fridge. Avoid fast charge or discharge as they tend to catch on fire.

    Lithium Polymer: Same as lithium ion, but higher energy density so more tendency to catch on fire. Lighter than Lithium ion.

    A lemon, a copper nail and a zinc nail: Not rechargeable but you can replace the lemon as needed.

    * Notes: Battery performance/management is a bit of an art. Everyone has an opinion. The above is my opinion, others may differ. Do not apply orally, see a doctor if pains persist.
    • Like Like x 2
  3. LOL

    Thanks for the info.
  4. Works with coke and a strip of aluminium and copper too (though as above zinc works better than alu)!
    I powered a real small radio i made in high school with it.

    Almost anything somewhat acidic will generate a current... hint vinegar :p.

    I opted against LiPe (lithium polymer) battery for my bike after they actually revealed they suck with a realistic starter motor drain test. After 1 cycle of 10 seconds the electrolyte was boiling and the battery could no longer turn over the motor - shorai.
    Holds promise and im interested, but seems a little early to jump the gun :p.

    Stuck with AGM for now, and can recommend a trickle charger yes.
    Got a CTEK MXS5.0.
  5. Check out hobbyking dot com for batteries - I would recommend the LiFePo4 (Lithium Ferrous-Phosphate) batteries, especially their 4-cell 4.2 and 8.4Ah packs. They're rated to 30C constant discharge (126 and 252 amps respectively!) and I have had heard people having no problems with using the 4-cell 4.2Ah pack in a late model 600cc Ninja.

    I use their smaller packs in my electric model airplanes and frequently discharge them at maximum stated rate without ill effects. Many of these packs are still around with near full capacity and discharge rate after 18 months and I expect them to be still around in another year. Frequent cycling (ie riding) keeps them healthy.

    BTW, LiFe batteries are very stable and offer superior (500 to 1000+) cycle life. They have a nominal voltage of 3.3v/cell, topping out at 3.6v/cell, thus a 4-cell pack is best for automotive use. If you get thingy about them I'd put them on a balance charge once a month - the charger I use is worth $20 from the aforementioned site (Turnigy brand) and works a treat.

    Cheers - boingk
  6. Another vote for the turnigy cells. I've used a 4S rc lipo pack to jump start a car with a flat battery. The current those things can put out is ludicrous
  7. Took my battery to work and hooke it up to a laboratory power supply to recharge it. @14.40VDC till the current dropped and remained unchanged for a few hours which was 0.12A

    Been a 8 days now and it reads 12.67VDC on a Multimeter.

    Charger I have at home is 2.4A not sure how smart it is. Pretty sure its just a bulk charger.

    Anyway's I will get something decent for home. This MXS5.0 looks good thanks for the recommendation.
  8. I have a lemon tree in my back yard, how many lemons will I need to generate 12 CCA?

  9. Depends on the acidity of the lemons and the surface area of the zinc you use.

    But would probably be somewhere around the 600,000 mark.
  10. Hmmmm... Might need a sidecar...