Overcharging Batteries – Scooter Batteries

When performed correctly (and as soon as possible after using the scooter), charging a set of scooter batteries is about as complicated as plugging in the right amperage trickle charger with automatic cut-off and disconnecting it at the end of its proper recharge cycle. However it may be nearly impossible to fully charge an old battery that is nearing the end of its usable lifespan, or perhaps has seen too many seasonal extremes of hot summers and cold winters. It may be tempting to try and force a charge that the marginal battery doesn’t want to take, but this is a self-defeating and often a dangerous thing to do.

An inherent issue with almost any type of rechargeable battery, whether it sparks your Jazzy, your Vespa, your car or your MP3 player, is the problem of overcharging. Too much charge can cause heat and pressure to build up to inside of the battery until it deforms the exterior case. Automotive and marine batteries –which are in fact just larger versions of scooter batteries — have been known to burst after being grossly overcharged.

There are several ways your battery may try to tell you that it has been overcharged. Depending on your scooter model, very often the batteries themselves are hidden away under decks and panels, so it is a good idea to visually inspect them at the time of every recharge session. If your scooter battery is exhibiting any of these four symptoms, overcharging is probably the culprit.

Scooter Battery

  • Won’t Hold a Charge
    Overcharging a battery will degrade the lead plates between the cells, causing the electrolytes to evaporate, reducing its ability to hold the charge. Reduced electrolytes further increase the heat inside of the battery, which boils off even more electrolytes in a vicious cycle ad infinitum.
  • Overheats
    As the lead plates degrade from the overcharging process, internal electrical resistance increases. This resistance is felt as excessive heat on the batteries’ plastic case. This increase in heat further evaporates the electrolytes, causing even more destruction to the cells.
  • Leaks & Residue
    Scooter batteries are supposed to be fully sealed and all but leak proof. The heat and pressure from overcharging can cause the outer case to crack and leak acid. Often corrosive “salts” are visible around the seams.
  • Warped, Swollen, & Busted
    The most obvious sign of severe overcharging is a battery’s case that has been warped, rounded, bloated or bulging. Excess heat and pressure inside of the battery can eventually split the case wide open, spilling acid. In extreme cases, a single spark from a bad electrical connection or even static electricity can ignite the explosive gas and spoil your whole day.

The best charge for almost any battery is a slow trickle charge which cuts off automatically when the desired charge is reached. On the other hand, the worst charge for a scooter battery is a boost or jump from one of those high-amp automotive chargers. A boost charge is far too “hot” for the relative low-amp batteries found on most small scooters, and will probably damage the batteries as much as rejuvenate their power.

It cannot be stressed enough that getting a good scooter battery recharge starts with having the correct battery charger for your scooter.

3 thoughts on “Overcharging Batteries – Scooter Batteries

  • Great post! Problems with scooter batteries are sometimes hard to detect because they are so small. I had a friend that overheated his battery in the middle of the road, fortunately he got some help and his battery was under warranty.

  • Question,
    I just purchased a used EV Rider Stand and Ride Mobility Scooter, used. It is not holding a charge. Figures, I just bought it 2 days ago.
    I want to replace the batteries as they are not holding a charge. I have the 12V 20AH sealed lead acid batteries in my cart to purchase. (An upgrade from the current 12V 18AH)
    However, I can’t figure out how to get the case off the current batteries to change them out. I don’t want to purchase them if I cannot get the case off the batteries. I removed all the screws under the case and now there seem to be two more that are holding it down where it connects the charging plug. They spin and spin but won’t come out. Any ideas on how I can replace them? If so, I’ll order the replacement batteries. I just can’t figure out why the two screws won’t come out?
    If you know, please advise.
    Thanks much,
    Ragan Brown

    • These batteries will defitantly come out and they are meant to, so that they are able to be replaced. I have located a user manual for the Ride Mobility Scooter it does have a battery installation section. I am not to sure if one came with it or not. However it does not have anything on taking out the screws etc. Here is the link for pdf version of the user manual. When I did some digging around the forums and google I found that this is somewhat of a normal problem in these models I am going to keep looking around and asking several people what they have done or recommend doing when the screws can not be removed.

      Link to user manual: http://evrider.com/manuals/SNR-1000.pdf

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