What amp charger?

[Kyle Sandberg]

While buying a new battery, the salesman told me that you should use a 1.5 amp charger instead of a 2 or 10. He went on to say the higher amp burns out the battery. What do you guys think?

[harvey lee]

I have used a 2amp maintainer for years without any problems. I still use it today and my batteries will last very well.

I always put my charger on the battery as soon as I get home and do believe that helps alot in battery life.

[Whoaru99]

Me thinks it's an old wives' tale...

I have a 10-amps-per-bank charger and I believe this is year 5 or 6 on the same pair of relatively low cost (~$60/each) batteries.

About the only one to really look out for is the true gel cell. They don't like real high charge rates because the construction and gel electrolyte does not allow the gasses from charging to readily escape.

The two worst things for a battery, IMO, are not charging soon after use and/or maybe using a manual charger and forgetting to shut it off - essentially cooking the battery.

[Cabela10]

It is true... the 1.5 or 2 amp trickle chargers are the way to go. It's better to bring the batteries back to full charge slow. Don't ask me why, but the faster you charge them or the more amps you have going to each battery "CAN" do harm to the batteries. I'm read and heard this from professional installers and numerous fisherman.

[Surface Tension]

I use a Schumacher 15 amp charger. Its good for Flooded,

Auto, Truck, Marine, SLA, AGM, and GEL batteries. Believe me, I have deep cycle batteries that are over 10 years old.

I'll have to go out and get the dates off them.

I keep the fluids up and batteries charged, thats it.

Now this might be a 15 amp charger but its not charging at 15 amps all the time. In fact I don't think I've seen it charge at over 8 amps and it tapers down to nothing like it should. If and when I have to replace the charger I know what I'll be getting.

I'm not saying a 1.5 amp charger isn't going to work because it will. Something to consider is if your battery is at 50% after a day on the water and you plan to use it the next day, calculate the charge time. 1.5 divided by say 50 amps = 33 hours.

I can hook up my Schumacher, leave it on overnight without worrying about over charging it and its ready in the morning.

[harvey lee]

Exactly right Frank. I use to have a charger like your talking about and it worked great. Now, with the 2 amp, it takes forever to charge up for the next day and then I only have a partially charged battery.

[efgh]

Shumacher makes a charger that has setting for 2 amps, 15 amps, 50 amp boost, also deep cycle and regular batterys. It costs more than a regular charger but isn;t much bigger. I really like it because you can boost a lawn mower or any small engine that has electric start.

[mnfishman]

If you are buying an onboard charger they come in 5, 10 or 15 amps per bank. The size of the charger should be determined by how often you fish. If you are tournament fisherman and you need to recharge your batteries after a days use for the next tournament then a 20 amp charger per bank is the way to go. It will be able to recharge your batteries faster. If you are like me and you fish once or twice a week but never consecutive days then a 5 or 10 amp is fine.

The onboard chargers are all smart chargers where once the battery is fully charged it goes into maintenance mode and it will keep your batteries topped off. They will not cook your batteries unless the battery is bad and it won't take a full charge(happened to me last year not good). A good brand of on board charger is a Dual Pro charger if you are in the market.

[sparcebag]

I've got chargers 4 of them but I just purchased one from menard for 46$ 2-6-10 amp auto shut off,Gonna off all the others it's nice.I also have read the slower the charge going into a battery the longer the battery life and a longer lasting charge,I guess at slow low amps the battery can store better.the 1 amp & 2 amp motorcycle bat chargers I have work great but like surface said they need lots of charging time!

[Cabela10]

Quote:

---

I'm not saying a 1.5 amp charger isn't going to work because it will. Something to consider is if your battery is at 50% after a day on the water and you plan to use it the next day, calculate the charge time. 1.5 divided by say 50 amps = 33 hours.

---

I'm not positive, but I'm thinking it's not calculated like that. My 2 amp on board charger takes 8 hours to charge batteries from drained state, no juice. So I'm not sure where you got your 33 hours.

I think it only takes a 1.5 amp trickle charge like 12 hours to charge fully.

[PierBridge]

I wish....

[Surface Tension]

My calculations are correct. If you had a fully discharged 115 AH battery charging at 2 amps it would take you around 70 hours to charge it.

[harvey lee]

I agree with those numbers Frank. My deep cycle takes 3 days on a 2 amp after a day of fishing. Way to long. I usually have to use a bigger charger if I'm going out the next day.

[Whoaru99]

Quote:

---

I'm not positive, but I'm thinking it's not calculated like that. My 2 amp on board charger takes 8 hours to charge batteries from drained state, no juice. So I'm not sure where you got your 33 hours.

I think it only takes a 1.5 amp trickle charge like 12 hours to charge fully.

---

You must return to the battery what was removed, and perhaps slightly more due to losses.

I'm not disputing your recharge time, but if that's the case, then the batteries are either very small capacity or they were not discharged very much.

Recharge calc is pretty straighforward.

(Amp-hours of the battery X % of discharge) / amps of charger = approximate time to recharge.

[harvey lee]

All I know is the charger is on for three days before the light comes on that it is fully charged. Battery and charger are both brand new also.

[sparcebag]

Just drained my batt. today at 2A it will be ready in bout 50-55 hrs but I'll start it @ 6A and finish W/2A. I can probably cut time down to 18-20 hrs.

[Cabela10]

I've got two Trojan 27 series batteris which has a 115AH I believe and a Trojan starting battery. When I'm on my trolling motor all day long running the shore for bass, it usually only takes my batteries 4-6 hours to charge, unless my amps for charging is way higher than I thought, ha ha ha. Could be the case. Trolling motor is a 80lb thurst Maxxum Pro.

[firebug]

WHEN I BUY NEW BATTERIES. I LIKE TO DRAIN THEM WITH A 12VOLT LIGHT AND THEM RECHARGE THEM THEN DRAIN THEM. THIS WILL HELP THE BATTERY GET A MEMORY. I'VE SOLD THE MINN KOTA 5AMP CHARGES AND THEY CHARGE UP THE BATTERIES REALLY WELL. THEY COME WITH A 3 YR. WARRANTY AND THEY HAVE A $25.00 REBATE ON THEM NOW.

[Cabela10]

I thought deep cycle batteries don't have memory?, so there would be no reason to drain and recharge them to give them a memory. Is this right or wrong?

[Surface Tension]

Deep Cycles don't get a memory. When the battery goes dead or low for that matter its starts to sulfate. Thats the reason for charging it as soon as you can. Short periodic uses then charged ASAP is way better then draining them down low.

When I look back, the batteries that were used with a trolling motor without a Maximizer(Minkota's Technology)were the batteries that didn't last more then a couple years. That is probably attributed to the battery being drawn down low at almost every use which accelerated the sulfacation(sp).

Any Deep Cycle Multistage charger will give you the Absorbsion, Bulk, and Float charge that your battery needs and you won't have to worry about boiling and over heating your battery.

So if you charge your battery as soon as you can, keep the levels up, and charge periodically during storage, you've done all you can to ensure the batteries life what ever that may be.

[pfluemis]

Quote:

---

Quote:

---

I'm not positive, but I'm thinking it's not calculated like that. My 2 amp on board charger takes 8 hours to charge batteries from drained state, no juice. So I'm not sure where you got your 33 hours.

I think it only takes a 1.5 amp trickle charge like 12 hours to charge fully.

---

You must return to the battery what was removed, and perhaps slightly more due to losses.

I'm not disputing your recharge time, but if that's the case, then the batteries are either very small capacity or they were not discharged very much.

Recharge calc is pretty straighforward.

(Amp-hours of the battery X % of discharge) / amps of charger = approximate time to recharge.

---

Ummm, going by your formula, it would take 2500hrs for a 2 amp charger to charge a 100 amp/hr battery that was 50% drained.

100 X 50 / 2 = 2500

[pfluemis]

Quote:

---

While buying a new battery, the salesman told me that you should use a 1.5 amp charger instead of a 2 or 10. He went on to say the higher amp burns out the battery. What do you guys think?

---

10% of the amp/hr is a good rule of thumb. For example, if you have 200 amp per hour batteries, the charger should put out 20 amps to each battery. Faster charge is better than slow charge to the point you are not heating or over charging the battery. The 4 things that kills batteries are, heat, over stressing (over charging), low electrolite, and leaving a battery drained.

[Pat K]

pfluemis, in the formula, 50% would equal .50

100 x .5/ 2 = 25 hours.

Wouldn't be any time for fishing if it took over 3 months to charge our batteries!

[pfluemis]

Quote:

---

pfluemis, in the formula, 50% would equal .50

100 x .5/ 2 = 25 hours.

Wouldn't be any time for fishing if it took over 3 months to charge our batteries!

---

No, in the formula, 50%=50.

If 50% should be .5, then the formula that is trying to be conveyed should read:

(Amp per hr(% discharge/100))/amps of charger

(100(50/100))/2

(100(.5))/2

50/2

25

[Pat K]

50%=50/100=1/2=.5

[Whoaru99]

Quote:

---

50%=50/100=1/2=.5

---

Thank you.

[HaywardBound]

Quote:

---

50%=50/100=1/2=.5

---

Now I'm confused, you mean half full or half empty?

[pfluemis]

Quote:

---

50%=50/100=1/2=.5

---

Nice try....wrong. The formula clearly said to insert percentage of drain. That means the number 50 must be inserted. Nowhere in the formula was there a conversion for the percentage to be made into a decimal or fraction. Accuracy is the only way to get a mathmatical formula to work correctly. There is NEVER any room for assumption in a mathmatical formula.

[Cabela10]

I thought a % always gets converted to a .50 when in an equation. It just simply doesn't turn into a 50. You put it in the calc as 50% or .50 It's always .50, you always move the decimal point over 2 spots. Learned that in like 6th grade.

[Whoaru99]

Quote:

---

Quote:

---

50%=50/100=1/2=.5

---

Nice try....wrong. The formula clearly said to insert percentage of drain. That means the number 50 must be inserted. Nowhere in the formula was there a conversion for the percentage to be made into a decimal or fraction. Accuracy is the only way to get a mathmatical formula to work correctly. There is NEVER any room for assumption in a mathmatical formula.

---

Percent is universally understood (by most, anyway) to mean a fraction having a denominator of 100.

So, when the formula say PERCENTAGE of drain (using the example of 50) it means 50/100, or 0.5.

No need to make such a simple and universal concept so difficult.