Battery Charging Questions

[Tom-TX]

I have an electric fence around 2 sides of my hay field, and have 2 12V batteries, whick I put one on the fnece charger, take the other to barn and charge it.
One battery is Kirkland (Costco brand) and is a "marine starting and deep cycle conbination battery" the other is a Stowaway brand and is a "deep cycle" only battery.
Questions:
1. My charger has 2-amp or 20-amp setting.
Which charging rate setting is best, if time is not an issue?

2. My charger has buttons for selection of battery type: regular, deep cycle, or agm.
Which setting should use for the combination starting/deep cycle battery?

3. I have seen charts on the internet which say that 12.7 volts (tested the day after finishing the charging) is 100 percent charged.
Would this vary for starting battery versus deep cycle?

Thanks for your input.
Tom

 

[John T]

1. My charger has 2-amp or 20-amp setting.
Which charging rate setting is best, if time is not an issue?

If times NOT an issue Id opt for a long slow 2 amp charge....Although if its real low it wouldnt hurt to give her 20 amps a while to bring her up then top her off with a long slow 2 amp

2. My charger has buttons for selection of battery type: regular, deep cycle, or agm.
Which setting should use for the combination starting/deep cycle battery?

Id "guess" deep cycle not having any specs or data in front of me, its not a pure regular and not a AGM so that sort of narrows it down Id say

3. I have seen charts on the internet which say that 12.7 volts (tested the day after finishing the charging) is 100 percent charged.
Would this vary for starting battery versus deep cycle

NO Both are still flooded lead acid bateries

John T

 

[Geo-TH,In]

Many chargers sold today are smart chargers that will turn off when the battery is fully charged. They have settings for marine batteries, 2 amp, 15 amp and jump starting modes. Depending on the amp hour rating of the battery, you may want to use the 15 amp setting for a marine battery.

I use the 2 amp setting for charging a mower and cycle battery.

I think the 2 amp setting is better than using a trickle charger. You can leave a smart charger on for weeks without damaging the battery and it will turn on automatically when needed and they won't over charge a battery like the old manual chargers.

The down side to a smart charger is they won't charge a completely dead battery.

 

[Kentb of SWMO]

For the deep cycle only battery use the deep cycle position on the charger and the 2 amp setting. For the marine starting and deep cycle battery I would use the 2 amp setting and the regular setting on the battery type.

Kent

 

[36 Coupe]

Get a hydrometer and check the state of charge.Batteries quickly take on a surface charge.Smart chargers aint as smart as you think.A 20 amp rate is too much.Batteries start gassing at 6 amps.

 

[ASEguy]

Best charging rate on most lead acid batteries is the lowest setting or 1-2 amps. If the battery has sulfated somewhat it will allow the sulfated substance to flow back into the water/acid mixture. A fully charged battery, if it's a 12 volt battery is 12.65 volts because each of the six cells has a fully charged voltage of 2.1 volts. I would use a hydrometer to determine charge condition. If any cells vary by more than 50 points with a hydrometer the battery is considered defective. Hope this helps. Gerard

 

[buickanddeere]

Depends on who you ask. Some folk who have boiled a battery over or boiled a battery dry will shy away from rapid charging.
Anybody ever care to guess just how many amps the 160 amp charging system on your vehicle rams into the starting battery on your vehicle. For the first 5-15 minutes after starting? Certainly not as much now with fuel injected vehicles as the bad old days with carbs but......... A 50amp bulk charge is not uncommon.
As for backup batteries in a nuclear plant. If caught trickle charging them after a deep discharge test. You will screamed at by the supervisor and a few engineers for sulphating the plates.
A heavy fast high current bulk charge at 5-10% of the battery current capacity is used. 1000amp battery is charged at 50 to 100amps. As long as the battery isn't over filled , it doesn't boil.
Actual temperature is more of a concern. Above 77F a lead acid battery's life is shortened at an exponential rate.
At approx 80% charge the rate is backed off to a trickle to 100%.