Battery tender vs trickle charger
12-27-2009, 01:24 AM
#21
Burning Brakes
Here is some info on batteries:
http://jgdarden.com/batteryfaq/carfaq14.htm
And this:
http://jgdarden.com/batteryfaq/carfaq15.htm
http://jgdarden.com/batteryfaq/carfaq14.htm
And this:
15. HOW LONG CAN I PARK MY VEHICLE?
The amount of time, usually referred to as "airport", "garage", or "storage" time, that you can leave your vehicle parked and still start your engine is dependent on such things as the battery's initial State-of-Charge (SoC), the Reserve Capacity (or amp hour capacity), the amount of natural self-discharge and parasitic (ignition key off) load, temperature and battery type (plate chemistry). Car manufacturers normally design for at least 14 days or more "airport" time; based on a fully charged battery in good condition, moderate weather, and no additions to the original car's parasitic load (for example, an after market alarm system). The number of days will vary based on the temperature. When a battery drops below 100% SoC, sulfation starts slowly occurring, and this will reduce the capacity of the battery and if left unchecked, will kill the battery.
If you leave your vehicle parked for more than two weeks, then you have several options:
15.1. The best long term (over one month) option is to continuously float charge your car battery by connecting a "smart" battery charger or a voltage regulated float charger because it will keep the battery fully charged, thus eliminating sulfation. If there is no AC power available, use a five watt (or greater) solar float charger. These options will allow you to park you vehicle indefinitely, but the battery should be checked periodically. You will need a "float" charging voltage between 13.2 and 13.8 VDC at 80° F (26.7° C) and at least .5 amps (500 milliamps) to overcome the vehicle's parasitic load and the natural self-discharge of the battery. Do not use a cheap "trickle" charger, because it will overcharge your battery and dry out the electrolyte.
15.2. Disconnect the grounded battery cable (which is normally the NEGATIVE (-) cable) to remove the parasitic load, but be sure that you have saved any security codes or radio stations presets that will have to be reprogrammed, but the battery's natural self-discharge will continue. This option will work from one month to six months depending battery type and temperature.
15.3. Replace the battery with the largest AGM (Ca/Ca) or Spiral Wound AGM VRLA battery that will fit, e.g., an Optima or Exide Select Orbital, with very low self-discharge rates. For periods greater than two months, also disconnect the grounded battery cable to remove the parasitic load. This option will work for six months to twelve months depending battery type and temperature.
15.4. Install a battery with a larger reserve capacity or connect an identical battery in parallel, but the battery's natural self-discharge will continue. For periods greater than two months, also disconnect the grounded battery cable to remove the parasitic load. This option will work for two months to twelve months depending battery type and temperature.
15.5. Replace the battery when you are ready to drive the vehicle again, especially if the battery is over three years old and in a hot climate.
15.6. Have someone drive your car during the day at highway speeds every two weeks for at least 15 minutes to keep the battery charged.
15.7. Jump start the battery and hope that there is no latent damage.
15.8. Install a low voltage disconnect. This is especially helpful if the driver forgets to turn the headlights off.
The amount of time, usually referred to as "airport", "garage", or "storage" time, that you can leave your vehicle parked and still start your engine is dependent on such things as the battery's initial State-of-Charge (SoC), the Reserve Capacity (or amp hour capacity), the amount of natural self-discharge and parasitic (ignition key off) load, temperature and battery type (plate chemistry). Car manufacturers normally design for at least 14 days or more "airport" time; based on a fully charged battery in good condition, moderate weather, and no additions to the original car's parasitic load (for example, an after market alarm system). The number of days will vary based on the temperature. When a battery drops below 100% SoC, sulfation starts slowly occurring, and this will reduce the capacity of the battery and if left unchecked, will kill the battery.
If you leave your vehicle parked for more than two weeks, then you have several options:
15.1. The best long term (over one month) option is to continuously float charge your car battery by connecting a "smart" battery charger or a voltage regulated float charger because it will keep the battery fully charged, thus eliminating sulfation. If there is no AC power available, use a five watt (or greater) solar float charger. These options will allow you to park you vehicle indefinitely, but the battery should be checked periodically. You will need a "float" charging voltage between 13.2 and 13.8 VDC at 80° F (26.7° C) and at least .5 amps (500 milliamps) to overcome the vehicle's parasitic load and the natural self-discharge of the battery. Do not use a cheap "trickle" charger, because it will overcharge your battery and dry out the electrolyte.
15.2. Disconnect the grounded battery cable (which is normally the NEGATIVE (-) cable) to remove the parasitic load, but be sure that you have saved any security codes or radio stations presets that will have to be reprogrammed, but the battery's natural self-discharge will continue. This option will work from one month to six months depending battery type and temperature.
15.3. Replace the battery with the largest AGM (Ca/Ca) or Spiral Wound AGM VRLA battery that will fit, e.g., an Optima or Exide Select Orbital, with very low self-discharge rates. For periods greater than two months, also disconnect the grounded battery cable to remove the parasitic load. This option will work for six months to twelve months depending battery type and temperature.
15.4. Install a battery with a larger reserve capacity or connect an identical battery in parallel, but the battery's natural self-discharge will continue. For periods greater than two months, also disconnect the grounded battery cable to remove the parasitic load. This option will work for two months to twelve months depending battery type and temperature.
15.5. Replace the battery when you are ready to drive the vehicle again, especially if the battery is over three years old and in a hot climate.
15.6. Have someone drive your car during the day at highway speeds every two weeks for at least 15 minutes to keep the battery charged.
15.7. Jump start the battery and hope that there is no latent damage.
15.8. Install a low voltage disconnect. This is especially helpful if the driver forgets to turn the headlights off.
12-27-2009, 10:54 AM
#22
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St. Jude Donor '09-'10, '14
But a trickle charger is fine also. They will shut themself off when a battery is fully charged, or at least the one I have does.
I completely understand why people use a tender but taking care of a battery is not rocket science either. Just plug it in every couple weeks and your good. Once a month is adequate.
I have never used a tender and never had any problems with my Dodge Ram or vette, whch both sit for extended periods of up to a month. The vette in some cases longer but not often.
But for full disclosure I have been thinking of buying a tender, just cuz.
Last edited by RetiredSFC 97; 12-27-2009 at 10:58 AM.
12-27-2009, 05:59 PM
#23
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Just out of curiosity, is it necessary to disconnect the battery when using a tender? Is there a possibility of damaging the electronic dash if you leave the cables connected?
85 Gold
85 Gold
12-27-2009, 07:51 PM
#24
Burning Brakes
I bought 2 of the Black & Decker automatic battery tenders for my Boat. They offer a choice of 1 amp or 2 amp charge. They were $20 each. So far, no problems.
12-27-2009, 08:00 PM
#26
Race Director
12-27-2009, 09:46 PM
#27
Flatulent Dwarf
Never had a problem with my digital stuff using the Battery Tender....the REAL Battery Tender has copyrighted circuitry and algorithms....if y'all would go to the link I put in a few messages back you can see for yourself and get just about all the questions answered.
12-27-2009, 11:08 PM
#28
Melting Slicks
The beauty of the Battery Tender (TM) is that it shuts itself off when the batt is full charged. Trickle chargers do not. That is why they are typically cheaper.
Last edited by MK 82; 12-27-2009 at 11:14 PM.
12-28-2009, 11:12 AM
#30
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St. Jude Donor '09-'10, '14
The typical lead acid battery self discharges at about 4 to 6% per month. So your 4-6 wks should produce about 5 to 8% discharge-not flat. This does not take into account any parasitic drains. Batteries don't rot internally.
The beauty of the Battery Tender (TM) is that it shuts itself off when the batt is full charged. Trickle chargers do not. That is why they are typically cheaper.
The beauty of the Battery Tender (TM) is that it shuts itself off when the batt is full charged. Trickle chargers do not. That is why they are typically cheaper.
My trickle charger shuts itself off when the battery is charged. Well it doesn't actually shut completely off but it does quit charging.
12-28-2009, 11:20 PM
#31
Melting Slicks
12-29-2009, 10:19 AM
#32
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St. Jude Donor '09-'10, '14
First because the instructions tell me it does. 
And second, if you look at the charger dial, it will go down to the position as if it is turned off.
I have hooked up this charger, on my tractor, and got busy and forgot I had it hooked up and after several hours went back to find all was ok and the dial was in the off mode.
I believe a tender is the easiest and probably safest way to go but not a have to. I also believe if you just put a trickle charger on for a couple hours once a month everything will be fine.
just depends on what type of set up a person has. I personally don't like to plug something in and just forget about it especially when it's around combustibles. It's probably safe but I get nervous.
But you cannot just hook up the trickle and leave it hooked up either. The cut off is just a safety mechanism.
And second, if you look at the charger dial, it will go down to the position as if it is turned off.I have hooked up this charger, on my tractor, and got busy and forgot I had it hooked up and after several hours went back to find all was ok and the dial was in the off mode.
I believe a tender is the easiest and probably safest way to go but not a have to. I also believe if you just put a trickle charger on for a couple hours once a month everything will be fine.
just depends on what type of set up a person has. I personally don't like to plug something in and just forget about it especially when it's around combustibles. It's probably safe but I get nervous.
But you cannot just hook up the trickle and leave it hooked up either. The cut off is just a safety mechanism.
Last edited by RetiredSFC 97; 12-29-2009 at 10:24 AM.
12-29-2009, 11:15 AM
#33
For $11 bucks why add an issue with the trickle
I have a $11 harbor freight tender (actually 2) and it has been flawless. I am not one for using something that it is not intended for, Trickle charger with a timer. For what reason, to save $11 dollars? I am a cheap one, but why do this?
My car sits for 3-4 months over the winter, I do start it and move it up and down driveway every 2-3 weeks and the tender does a greeat job.
My car sits for 3-4 months over the winter, I do start it and move it up and down driveway every 2-3 weeks and the tender does a greeat job.
12-29-2009, 12:20 PM
#34
It not only uses Float maintenance but also Pulse maintenance.
You can get one for $60 on ebay.
It's well worth the $60 http://www.youtube.com/watch?v=qHSI_qHOI4U
CTEK Sweden is proud to supply battery chargers and develop adapted solutions to some of the worlds most recognised car and motorcycle manufacturers in the world: Porsche, Mercedes, Maybach, Harley Davidson (Scandinavia), Aston Martin, Bentley, Ferrari and Lamborghini.
Charging process starts in the video at 2:40 seconds.
Last edited by xlr8nflorida; 12-29-2009 at 01:22 PM.
