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How about a battery charging / testing tutorial?


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I posted a while ago that I drained my relatively new YTZ10S by leaving the bike sit a couple weeks without a tender on it. (I have since disconnected the clock wire and will be sure to keep it plugged in 24 /7). Anyway I put it on a 2 amp cycle charger (not a tender) for 7 hours. I assumed this was plenty and didn't want to fry the thing. Apparently it was not, the battery was ok and just needed to be fully re-charged. That said, my questions are:

How long to charge? Is this based on ampere / hours? Is there a formula?

What is minimum voltage that a battery should have when a tender won't do and it will need a trickle charge such as this?

I have access to a Sun Vat-40 automotive-type load tester. I know with cars, you normally take half the cold cranking amps of the battery and load it to that amount for 15 seconds. The battery should read 9.6 volts or more to indicate a 'good' unit. Does this apply for cycle batteries?

Thanks in advance, YO

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Yo,

All very good questions.

There are general guidelines but lots of different answers. Your battery, is typical of AGM type sealed batteries, has a 1 hr charge rate and a 10 hr charge rate. (1 amp for 10 hr or 10 amp for 1 hr) Neither of which have very much to do with actual charge time. Your YTZ10S battery is a 10 amp hr battery (actually 8.6). So you might assume it could deliver 10 amps for 1 hr or 1 amp for 10 hr. In theory yes but in practice no. In practice, this type of battery is designed for starting (deliver lots of amps for a short time not the amp capacity over a longer time). For some strange reason M/C batteries are still sold by amp hr capacity not CCA. Charge rate is not highly important as long as it does not exceed the 1 hr charge rate (10 amps in your case). All cars and motorcycles seek to recharge the battery as quickly as possible after a start so the charging system is designed to do that.

A 2 or 3 amp basic charger is perfect for recharging. I just watch the terminal voltage to determine when the charge is complete. I look for 15 to 16 volts. The current will not stay constant so unless you have an amp meter in the system you do not really know the charge rate. "Smart chargers" with AGM setting will do a good job. Tenders I have my doubts about. Depends on brand, age and how hi-tech it is. The purpose of a Tender is to maintain charge not re-charge from dead. Once the battery is off the charger, let it sit for at least an hr no load then check the voltage. 13 to 13.2 volts is fully charged. If between 12.8 and 13, charge a little longer to see if the voltage will come up. If less the 12.8 after an extended charge period, the battery is probably not going to recover much more.

When a battery is really low like lights on for 12 hr, it some times takes a kick in the ass to get it going. By that I mean push the 1 hr rate for a little while (10 to 30 min) then switch to a lower charge rate. I'd say anything under 6 volts no load would need this treatment.

A load test is a good test for battery condition. But the specifications are not well published for motorcycle batteries. Your assumption of 1/2 CCA and 9.6 volts is a good assumption but I can not verify it. I have to wonder how many "good" motorcycle batteries would pass that test.

The standard YT7B-BS has a CCA of 85. The YTZ10S has a CCW of 190.

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So let me get this straight, I charge the battery at 2 amp for say 6 hours. Disconnect it for an 1/2 hour or so to stabilize, and if it doesn't read 15 or 16 volts it needs more charge?

No wonder my bike wouldn't start.....

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So let me get this straight, I charge the battery at 2 amp for say 6 hours. Disconnect it for an 1/2 hour or so to stabilize, and if it doesn't read 15 or 16 volts it needs more charge?

No wonder my bike wouldn't start.....

Once the battery is off the charger, let it sit for at least an hr no load then check the voltage. 13 to 13.2 volts is fully charged. If between 12.8 and 13, charge a little longer to see if the voltage will come up. If less the 12.8 after an extended charge period, the battery is probably not going to recover much more.

I think this is what Noble said, the 15-16 is when the battery is still on the charger.

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4 real - Your reference to the Yuasa manual is excellent. More info in 41 pages than could ever be presented here.

However if you could be more specific as to my "bad information", I would appreciate it. I am always willing to learn from those more knowledgeable than me. The 41 page Yuasa manual certainly is more in depth and complete but I don't see where it gives significantly conflicting information.

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4 real - Your reference to the Yuasa manual is excellent. More info in 41 pages than could ever be presented here.

However if you could be more specific as to my "bad information", I would appreciate it. I am always willing to learn from those more knowledgeable than me. The 41 page Yuasa manual certainly is more in depth and complete but I don't see where it gives significantly conflicting information.

First, I do not claim to be an expert. I have just spent a lot of time reading the manuals and researching charging algorithms and technology online. No disrespect intended, either.

1) The terminal charge voltage should be at the gassing voltage of ~14.4V at ~25C, not 15 -16V. 15 - 16V is too high and will cause excess hydrogen gas to be expelled. Since AGM is recombinant tech, that gas will be lost for good leading to less capacity over time. 15 - 16V is only for equilization of "wet" lead-acid batteries that can have their electrolyte/water replensished.

2) I think you are confusing capacity © in AH and charge rate. Yuasa wants a charge rate of no more than 1/10c for AGM. For a 10 AH battery, that means no more than a 1 A charge rate. Some other AGM manufacturers allow up to 1/3c.

Also, Yuasa specs most of their batteries at a 10-hr discharge rate. Thus, a 10 AH battery would be able to discharge at 1 A/hr for 10 hrs. However, this does not mean it could also discharge (or be charged) at 2 A/hr for 5 hours, 3 A/hr for 3.33 hrs, etc. Rated capacity is affected by discharge rate, so that's why it always accompanied by a a time spec. http://www.yuasabatteries.com/pdfs/2008yuaapp.pdf

3) If a battery is severly discharged (steady state condition of < 11.5V), you do not want to push a 1c charge rate, 10 A in the case of a 10 AH battery. Instead, you want push a higher V (25 V max) to create a larger potential difference to try and drive the regular charge rate (1/10c) into the battery. This should only be attempted for ~5 min.

4) Finally, you didn't say this, but it takes more than 100% of c to recharge a fully discharged (< 11.5V) battery. Typically, the charge that must be returned to an AGM battery to achieve a 100% state of charge is from ~110% to 140% of the charge removed depending on the charge rate used (lower charge rate = higher efficiency because of less heat generation). For a 10 AH battery, that means it would need to be charged at 1 A/hr for 11 - 14 hrs to be fully charged back to 100%.

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the christie battery charger spec'd to be in all honda shops charges at 15+ volts. its is used on all batterys.

we service hundreds of batterys per month.

but i havent read the 41 page manual.

once again,big difference between "theory" and what really happens.

nobles info is fine.

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Both chargers that Yuasa currently sells (900mA & 1.5 A models) reach a terminal charge coltage of ~14.4 V.

"The ‘Charging Mode’ begins when the Yellow L.E.D. is on continuously and charges the battery to approximately 14.4Vdc and then transitions into the ’Float Mode’ where the Green L.E.D. illuminates."

http://www.yuasabatteries.com/chargers.php

http://www.yuasabatteries.com/pdfs/Safety_Inst_12v_Charger.pdf

The latest Multi-Tech model that Christie makes only goes to a max of 14.5V for AGM.

"Voltage and Current are regulated for a range of sizes from large marine deep cycle batteries to small sealed motor cycle batteries, whether the battery construction technology is regular flooded lead acid (max 16.5 charging volts) or the new AGM (absorbed glass mat), Gel, or Spiral (max 14.5 charging volts) battery constructions."

http://www.christieautomotive.com/products/MTC-2012.html

All data that I've seen on line from both charger & AGM battery makers has specified ~14.4V as the terminal charge voltage at 25 C.

"Concorde Battery Corp., manufacturer of a complete line of AGM batteries, calls for 14.1 to 14.4 volts for bulk charging and 13.1 to 13.3 volts for float charging, at 77º F (25º C). East Penn Manufacturing, another maker of AGM batteries specifies a maximum charge voltage of 14.6 volts . . ."

http://www.zimmermanmarine.com/docs/AGM%20article.pdf

AGM table on p11: http://www.eastpenn-deka.com/assets/base/0139.pdf

That is not to say a higher charge V & current will not work with AGM, only that the battery life will be less than optimal.

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the christie charger is the only charger ive seen save a marginal AGM battery.

you really should have looked at the actual small battery charger.

honda is anal about batteries on a whole different level.

like i said it is required equpment.

check out the initial charging and desulfation rates.

http://www.christieautomotive.com/products/C-1012_2-S.html

real world........

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4 real - I see you have read a lot of literature on charging and chargers. I don't wish to get into a peeing contest, your information is quite good. But as Eddie points out, the practical often wins out over the theory.

I still don't think my information is "bad information". Somewhat incomplete perhaps.

I will try to address a few of your concerns:

1) terminal voltage. Right you are that only wet cells need periodic "conditioning" to correct for under charging. This is normally done once a month on marine battery banks and really does not apply at all to auto or M/C batteries. I can assure you that bringing terminal voltage up to 15-16 volts for a short period with very low current for initial charge and occasionally in the life of the battery has worked very well for me. I am not proposing to do it at every charge cycle or to hold it there for long. Even Yuasa SmartShot charger provides up to 16 volts for recovery. Being a cheap SOB, I don't think anybody gets longer battery life from motorcycle batteries than I do.

2) I am not confusing amp hr capacity with charge rate. Every AGM battery on my battery bench has a slow charge rate and a quick charge rate printed on the battery They are not all consistent but in general the slow rate is 1/10 the battery size and quick rate is the same as the battery size. I can assure you that the on board motorcycle charge circuit does not charge the YT7B-BS at .7 amps.

3) Severely discharged. No argument. I'm sure you are right. However it is not the only procedure that works. When dealing with a battery that has been severely discharged for a day or a week or a month, there is not much to loose when trying various procedures to revive it. My advise is usually to take it to a dealer that can deal with it properly.

4) Charge time, OK.

*

I can not comment on the Christie battery charger at all. I do know it is a very fine charger and that Eddie knows his business. I think there is a lot more going on in a Christie and Yuasa SmartShot charger than meets the eye. My only comment is that if a person is going to depend on a charger to do the job right and to maintain a battery, buy a good quality product. If you are depending on an inexpensive basic charger with no internal electronics, my methods work.

Thanks for your input - lots to learn.

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the christie charger is the only charger ive seen save a marginal AGM battery.

you really should have looked at the actual small battery charger.

honda is anal about batteries on a whole different level.

like i said it is required equpment.

check out the initial charging and desulfation rates.

http://www.christieautomotive.com/products/C-1012_2-S.html

real world........

Are you saying the Model C 1012/2S is what Honda specs? If so, it appears that it is mostly a manual charger with user selectable charging current & charging time, but with charging voltage being controlled by the charger.

"Recover batteries with partial sulfation due to seasonal use or discharge during long storage periods. Electronic controls automatically adjust charging voltage (up to 22 volts) during de-sulfation mode.

Designed for small lead-acid and gel cell batteries, the C1012/2S charges two batteries simultaneously and independently at 12 volts. Simply connect, set charger rate (0-10 amps) and set timer control (0-2 hrs)."

http://www.christieautomotive.com/specsheets/C1012_2s.pdf

Given that Yuasa specs a charge rate of 1/10c for their batteries, I find it odd that Honda specs a charger where charging current is set manually.

Take a 10 AH AGM battery, for instance. In a worst-case scenario, someone could set this charger to 10 A and 2 hours. Not only would that charge at 10x the rate Yuasa specs, but it would also overcharge by a factor of ~42% in a best-case scenario causing a permanent loss of gas and corresponding loss of battery life. Do that too many times and the battery is runied.

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1) terminal voltage. Right you are that only wet cells need periodic "conditioning" to correct for under charging. This is normally done once a month on marine battery banks and really does not apply at all to auto or M/C batteries. I can assure you that bringing terminal voltage up to 15-16 volts for a short period with very low current for initial charge and occasionally in the life of the battery has worked very well for me. I am not proposing to do it at every charge cycle or to hold it there for long. Even Yuasa SmartShot charger provides up to 16 volts for recovery. Being a cheap SOB, I don't think anybody gets longer battery life from motorcycle batteries than I do.

The purpose of an equalization charge (15 - 16V) is to vigorously bubble & mix up the electrolyte (eliminate acid stratification) and put all of the lead sulfate back into soultion. Thus, it is not the application of the battery that determines whether an equilization charge is done, it is the construction. All "wet" lead-acid batteries can benefit from equilization whether they are marine, motorcycle, or auto. OTOH, AGMs do not benefit from equalization because of their (A)bsorbed (G)lass (M)at construction, which does not have free electrolyte.

The Yuasa only goes up to 16V for the initial charging of "dead" batteries. For terminal charging it still goes to 14.4V. Like I said previously, "dead" batteries (< 11.5V) may require a higher initial charge voltage to start accepting current. The 16V creates a larger potential difference to try and drive the regular charge current (1/10c) into the battery. This is consistent with what is described in Yuasa's Tech manual.

2) I am not confusing amp hr capacity with charge rate. Every AGM battery on my battery bench has a slow charge rate and a quick charge rate printed on the battery They are not all consistent but in general the slow rate is 1/10 the battery size and quick rate is the same as the battery size. I can assure you that the on board motorcycle charge circuit does not charge the YT7B-BS at .7 amps.

You are correct. 0.7A at 14.4V would only be a little over 10W. I was only making the point that Yuasa specs a 1/10c charge rate to 14.4V for their batteries for maximum life. Other rates and voltages can be used, but they will result in a loss of battery life.

I think there is a lot more going on in a Christie and Yuasa SmartShot charger than meets the eye.

If you want to know what the Yuasa and some other chargers are doing, follow the link below. It explores their algorithms in great detail and confirms the ~14.4V terminal charging voltages in actual operation.

http://www.wingworldmag.com/archives/august2002/magazine/article/battery.html

How critical is recharge voltage?Why are all VRLA batteries so charge

sensitive?

All lead-acid batteries give off hydrogen from the negative plate

and oxygen from the positive plate during charging.

VRLA batteries have pressure-sensitive valves. Without the ability

to retain pressure within the cells, hydrogen and oxygen would be

lost to the atmosphere, eventually drying out the electrolyte and

separators.

Voltage is electrical pressure. Charge (ampere-hours) is a quantity

of electricity. Current (amperes) is electrical flow (charging speed).

A battery can only store a certain quantity of electricity. The closer

it gets to being fully charged, the slower it must be charged.

Temperature also affects charging.

If the right pressure (voltage) is used for the temperature, a battery

will accept charge at its ideal rate. If too much pressure is used,

charge will be forced through the battery faster than it can be

stored. Reactions other than the charging reaction occur to

transport this current through the battery—mainly gassing.

Hydrogen and oxygen are given off faster than the recombination

reaction. This raises the pressure until the pressure relief valve

opens. The gas lost cannot be replaced. Any VRLA battery will dry

out and fail prematurely if it experiences excessive overcharge.

Note: It is the pressure (voltage) that initiates this problem—

a battery can be “over-charged” (damaged by too much voltage)

even though it is not fully “charged.”

This is why charging voltage must be carefully regulated and

temperature compensated to the values on page 11.

http://www.eastpenn-deka.com/assets/base/0139.pdf

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Are you saying the Model C 1012/2S is what Honda specs? If so, it appears that it is mostly a manual charger with user selectable charging current & charging time, but with charging voltage being controlled by the charger.

"Recover batteries with partial sulfation due to seasonal use or discharge during long storage periods. Electronic controls automatically adjust charging voltage (up to 22 volts) during de-sulfation mode.

Designed for small lead-acid and gel cell batteries, the C1012/2S charges two batteries simultaneously and independently at 12 volts. Simply connect, set charger rate (0-10 amps) and set timer control (0-2 hrs)."

http://www.christieautomotive.com/specsheets/C1012_2s.pdf

Given that Yuasa specs a charge rate of 1/10c for their batteries, I find it odd that Honda specs a charger where charging current is set manually.

Take a 10 AH AGM battery, for instance. In a worst-case scenario, someone could set this charger to 10 A and 2 hours. Not only would that charge at 10x the rate Yuasa specs, but it would also overcharge by a factor of ~42% in a best-case scenario causing a permanent loss of gas and corresponding loss of battery life. Do that too many times and the battery is runied.

it is the charger that honda specs.

like noble said it more than just a "battery charger".

you dont select the charge rate.you only select the rating of the battery.the charger does the rest.

no ruined batterys.

saves many batteries that have been previously on normal battery chargers with out success.

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you dont select the charge rate.you only select the rating of the battery.the charger does the rest.

When I look at the spec sheet (and the picture on it), I see an adjustable charge rate of 0 - 10 A that is manually selected via a dial. The spec sheet also says this, "Simply connect, set charger rate (0-10 amps) and set timer control (0-2 hrs)." Are you saying that is not the case?

http://www.christieautomotive.com/specsheets/C1012_2s.pdf

no ruined batterys.

An AGM battery is not always significantly ruined from an acute episode of overcharging. However, when it is is chronically overcharged, the loss of hydrogen, oxygen, and/or water & the positive plate corrosion will start to take its toll.

"Perhaps the greatest shortcoming of AGM batteries —

although less so now that it is well understood by most

boat builders and professionals in the marine industry —

is their sensitivity to chronic under- and overcharging"

"Because of the recombinant technology

used in AGMs,they are entirely intolerant

of venting.That is, if seriously overcharged,

their regulating valves will

open to prevent over-pressurization of

the case, resulting in a permanent loss of

hydrogen and oxygen or water. If

allowed to continue, this process, tantamount

to never adding water to a conventional

flooded cell, will eventually

destroy the battery."

"Even if the battery isn’t driven to the

venting stage, constant, chronic overcharging . . .

will lead to galvanic corrosion of the positive grid

and shedding of the active plate material, which is essentially

the muscle within every battery."

http://www.zimmermanmarine.com/docs/AGM%20article.pdf

"If the right pressure (voltage) is used for the temperature, a battery

will accept charge at its ideal rate. If too much pressure is used,

charge will be forced through the battery faster than it can be

stored. Reactions other than the charging reaction occur to

transport this current through the battery—mainly gassing.

Hydrogen and oxygen are given off faster than the recombination

reaction. This raises the pressure until the pressure relief valve

opens. The gas lost cannot be replaced. Any VRLA battery will dry

out and fail prematurely if it experiences excessive overcharge."

http://www.eastpenn-deka.com/assets/base/0139.pdf

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Once the battery is off the charger, let it sit for at least an hr no load then check the voltage. 13 to 13.2 volts is fully charged. If between 12.8 and 13, charge a little longer to see if the voltage will come up. If less the 12.8 after an extended charge period, the battery is probably not going to recover much more.

This is the bit that I have a problem with. You should let the battery sit over night with nothing connected to it for it to settle properly. Then you test the terminal voltage.

12.8 volts is fully charged

12.0 is very low state of charge

11.5 is damaged.

That is also real world and not fiction. I've spent much time on lead acid batteries due to a passion self build motorhomes (campers).

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