Thread: Shoot

Originally Posted by Mickey

Lead Acid batteries have a very low self discharge rate. The low wintertime temps reduce the self discharge rate even further. But with the low temps, the battery is less able to provide heavy current loads starters demand.

Winters are mild here and all I do when I put away the equip in the fall is to make sure the batteries are fully charged. Come spring I'll hook up a charger for a few min while I check the fuel and oil levels. Batteries tend to last 5 yrs on avg.

As for over charging, an automotive sized battery can handle a 2A charge rate in definitely without worry of over charging. A 5-6 watt charger is a little less than .5A. No way that small of current is going to hurt a battery. Even using a large charger, if the charge voltage isn't any higher than 13.8V, you can't over charge the battery.

Without some sort of "float" system in your charger, which means it stops the 2 amp effort...bad things result...

Exide Technologies FAQs - Marine & RV Batteries
Can you overcharge a deep cycle battery?
Overcharging a battery occurs when the battery remains on charge after it has reached full charge. Overcharging causes excess heat that can cause the plates within the cells to buckle and shed their active material. Also, the battery will react to the overcharge by producing excess hydrogen and oxygen as the water within the electrolyte breaks down. The water that is lost due to overcharging can be replaced in a non-sealed battery; in a sealed battery the water loss is permanent and will negatively effect the battery's service life.


Car and Deep Cycle Battery FAQ, Battery Manufacturers and Brand Names List, and
16.2. How do I prevent permanent sulfation?
The best way to prevent sulfation is to keep a lead-acid battery fully charged because lead sulfate is not formed. This can be accomplished in three ways. Based on the battery type you are using, the best solution is to use an external charger in a well ventilated area that is capable of delivering a continuous, temperature compensated "float" charge at the battery manufacturer's recommended float or maintenance voltage for a fully charged battery. For 12-volt batteries, depending on the battery type, usually have fixed float voltages between 13.1 VDC and 13.9 VDC, measured at 80° F (26.7° C) with an accurate (.5% or better) digital voltmeter. [For a six-volt battery, measured voltages are one half of those for a 12-volt battery.] This can best be accomplished by continuously charging using a three-stage for AGM (Ca/Ca) or Gel Cell (Ca/Ca) VRLA batteries or four stage for wet (flooded) batteries, "smart" microprocessor controlled charger. If you already have a two-stage charger, then use a voltage-regulated "float" charger or battery "maintainer", set at the correct temperature compensated float voltage to "float" or maintain a fully charged battery. If you need Web addresses or telephone numbers of charger manufacturers, please see the Chargers and Float Chargers and Battery Maintainers sections of Battery Information Links List. A cheap, unregulated "trickle" or a manual two-stage charger can overcharge a battery and destroy it by drying out the electrolyte.
A second method is to periodically recharge the battery when the State-of-Charge drops to 80% or below. Maintaining a high State-of-Charge tends to prevent irreversible permanent sulfation. The frequency of recharging depends on the parasitic load, temperature, battery's condition, and battery type. Lower temperatures slow down electrochemical reactions and higher temperatures will significantly increase them. A battery stored at 95° F (35° C) will self-discharge twice as fast than one stored at 77° F (25° C). Standard (Sb/Sb) batteries have a very high self-discharge rate; whereas, AGM (Ca/Ca) and Gel Cell (Ca/Ca) VRLA batteries have very low rates. Please see Section 7.1 for more information on battery types.
There are trade-offs between the economics of continuous "float" charging, where self-discharge and resulting sulfation does not occur, and periodic charging with the increased potential for a shorter battery life due to permanent sulfation. If you decide to periodically recharge the batteries while in storage, increasing recharge frequency, disconnecting any parasitic load, or storing them in colder temperatures will impede the self-discharge and reduce the possibility for permanent sulfation, but will also reduce the total number of life cycles.
A third technique is to use a solar panel or wind or water generator designed to "float" charge batteries. This is a popular solution when AC power is unavailable for charging. The size of a solar panel or wind or water generator required will depend on the average amount of available natural resource, battery capacity and temperature. Normally a five watt or larger panel is required for an average car battery. A charge controller (voltage regulator) is required when the peak current output exceeds 1.5% of the amp hour capacity of the battery.
A desulfator may be used in conjunction with any of the above methods.