Battery Charger

PGlaves said:

Without verifying the numbers I suspect that most any 12 v charger can charge most any 12 v battery to somewhere between 80% and 90% (or maybe a little higher) of full charge.

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True. Batteries reach 85 to 90% of full charge quickly. Its the last 10 to 15% that takes far longer to charge. That is why that stage is called "bulk charging" which is the constant current phase.

PGlaves said:

The penalty the owner pays for using less than the optimal charger for a specific battery is probably less than full charging and maybe reduced battery life.

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And possibly overcharging. Both cases shorten battery life.

Charge voltage depends on the battery temperature and ideally a battery charger should take cut-off voltage into account based on that. Unfortunately, our low priced chargers do not have that feature. The CTEL MULTI US 3300 has a two stage voltage cut-off that you select; either 14.4 or 14.7, the later is used for temperatures under 41F (your cold garage) or for certain AGM batteries that need the higher charge voltage.

We have a Cadex charger at work; there are three leads...positive, negative and a thermocouple temperature probe. Big coin though!

The following East Penn Technical Manual for GEL and AGM Batteries discusses battery voltage vs temperature (page 11) and battery life vs overcharging (page 4).

In a garage at 32F batteries should be charged to about 15V. Down in Texas in the middle of summer, that voltage should be about 14V.

And in the end, since our batteries are charged by the alternator most of the time, which I doubt temperature compensates, why worry about it.

PGlaves said:

What I pay the most attention to is the peak charging rate allowed.

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And the general and safe rule of thumb is 10% of the Ah capacity. In our cases, thats usually under 2A.

I've got chargers for my lead acid batteries, but I'm coming to suspect that they don't have the voltage for my AGMs, and I'm slowly converting everything that way. I have one Odyssey

So, studying all the above advice, I've checked the various battery charger suppliers. It's making my head swim, and I haven't been drinking today. (yet)

It appears that Odysee has helped develop a charger they recommend, the Optimizer, a big box and 6A for $110. But West Coast Batteries also describes the ACI Advanced Charger as acceptable for the Odyssey or any battery.

The "new" ACI charger is available in 3A for $55 and in 7A for $75.
from batterycentralmall.com.
http://www.batterycentralmall.com/Chargers/ACI/Tech.html

OK, I'm going into future shock over today's prices, but it seems to me that the ACI charger does what I need, for less bucks. Since I usually keep chargers on everything, price would be an object.

Opinions, please.

Here's a chart showing typical automatic functions

pmdave said:

Opinions, please.

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I'd go for the 1A model which they say is equivalent to 2A models.

None of my battery maintainers are more than 1A, and I have four Optimate III.

You'll never need to charge the battery that much anyways. The 1A unit will top it up in no time and just maintain it while it is parked.

Design of chargers

As a design engineer I've dealt with UPS and starter battery power charging & have dealt with AGM batteries for years. There is a fine balance between temperature compensated long term maintenance charging, charging to 100% and extending battery life on starter batteries. For deep cycle batteries constant delivery of power is important, so chargers should have temperature compensation and at least the minimum classic 3 stage charging algorithm / method, which is bulk, absorb and float. Some also have cell equalization. The absorb mode tops off the battery and for deep cycle this mode is important as that final 15-20% makes a big difference. It for the absorb mode you need temperature compensation as overcharging will most likely occur here. For starter batteries the final 15-20% is not that important as it's main job is to deliver instant massive current within 1 - 3 seconds (just to start turning the motor takes the most current). Even a 80-90% charged AGM can deliver it's stated current (they are usually over designed). Most maintenance chargers for starter batteries avoid temperature compensated charging as 1) they cannot predict what make and type of battery is being connected 2) each manufacturer demands a slightly different thermal regulation curve to the other. 3) Different batches from the same manufacturer have been known to have slightly different properties. Long term storage / maintenance chargers therefore use different methods with the better ones without temperature compensation not having an absorb mode. Now, slightly overcharging an AGM is certainly better than undercharging - they are designed with pressure valves that will only open if the pressure exceeds a high value, typically happens from 2,6V per cell (15,5V per 12V battery). So, if you hear a whistling sound from your battery, don't run, just disconnect that charger ASAP and don't use again! So, I suggest, if your charger claims to have an absorb mode (BT, ACI, Yuasa, AccuMate etc.), check if it is temperature compensated, otherwise the design should be taking the safest route - summer charging requires a lower voltage OR the current at which it stops charging in absorb mode should be at least 1/100C of your battery (0,2A for 20Ah), but the higher the better. If it does not, you should look for cyclic charging methods to top off the battery (OptiMate, CTEK being the better ones in my opinion). AGM batteries can last a long time and continue to deliver the starting current it is designed for, as long as they are properly maintained when not in use. That is a lot more important than charging to 100% every time within hours. In any event, over weeks of maintenance the charge will slowly creep up to 100%.

Design of chargers 2

Sorry, forgot to attach something that could answer the age old question: should I remove my battery from the bike in winter in temperatures below freezing? Not necessary if you keep the battery fully charged. A fully charged battery's electrolyte has specific gravity at 1,25 to 1,30 where the freezing point is minus 65 to minus 95 F.
Electrolyte in a discharged battery is more water than acid, specific gravity close to 1. Water expands 6/5 and will move / break anything in it's way to do so. As a result discharged batteries die in winter mostly due to internal mechanical damage (bent / shorted plates).
So, you can keep your battery in temperatures below zero as long as;
1) the battery casing can cope (most modern batteries can)
2) the charger is designed to operate down to your storage area's lowest temperatures. Cables are the weak point usually: std SPT2 cable is rated down to +8F, but will be stiff and the rubber/PVC will be easy to snap some degrees above that if bent, some chargers have SPT2W cable rated down to -40F, working temperature typically a few degrees above that though.

Thanks for the very helpful responses.

I had the stock AGM battery in my Spyder drain while sitting for about two months, and it has only recovered after several charging attempts. The battery checks out OK by the dealer, who believes that the parasitic loads can drain the battery very quickly, and some machines are more of a problem than others.

I've taken voltage measurements on all my chargers, and they all drop to a float voltage of 12.5V after an initial charge of 13.5 to 13.7V. That has worked OK for the lead/acid batteries in my motorcycles, tractor, etc. but apparently that's not high enough voltage for the AGMs. I am purchasing a new charger that will bring my AGMs up to recommended voltage.

Although my past habit has been to connect an automatic charger to each machine after a run and then leave it connected, I'm thinking that may be the lazy man's way, but not necessariily the best way to keep the AGM batteries alive.

I'm thinking that rotating a charger among the machines might be better, say moving the charger every week between three machines. That would allow each battery three weeks to discharge, then give it a shot to recharge up to capacity, then disconnect--which would prevent overcharging. The AGMs such as the Odyssey are reportetd to be much better at holding a charge (on the shelf) than the lead/acid types.

My machines are all parked in a heated garage, so low temperature isn't a problem.

pmdave

pmdave said:

I've taken voltage measurements on all my chargers, and they all drop to a float voltage of 12.5V after an initial charge of 13.5 to 13.7V. That has worked OK for the lead/acid batteries in my motorcycles, tractor, etc. but apparently that's not high enough voltage for the AGMs.

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Thats not even high enough for a flooded lead acid battery.

I have several different brands of "automatic" chargers, including Deltran, Battery Doc and Schumacher. I'm taking the voltage measurements at the battery installed in the machine with the charger attached.

For the first 24 hours or so, the voltage is only around 13.6 or 13.7. Then a day or so later the voltage drops to 12.5 (measured with a VOM)

I'll take some measurements when I get the new charger, and report back.

Does having the charger attached to the battery change the indicated voltage output of the charger? When attached to the AGM batteries, the chargers never seem to turn on the "float" light. They just keep humming away on "charge" as the voltage slowly drops down to 12.5

I described what was happening to a "battery tech" at the Seattle motorcycle show (I think it was the Yuasa booth, but maybe not), and he said, "it sounds like your'e doing the right thing." I'm thinking the right thing would have been to get out of the booth, fast.

pmdave

to pmDave; I am familiar with Deltran and Schumacher's operation, I have seen the Battery Doc before, on their site the specs only state 2 stage charging (constant current and then maintenance). However, this article on their site tells one a little more: http://www.batterydoc.com/pressh.htm
Battery Doc does not appear to have a maintenance mode where it continually delivers a charge, when the green light is on no charge is delivered. So it probably waits for the voltage to drop down below a certain level (per article 13V?), then goes back to charge mode. If so, it is a two stage cyclic charger.
Deltran BT Plus or Junior should have maintenance mode at 13,2V. Older versions only delivered 10mA in this mode, that may be why it is dropping to 12,5V? The Plus comes with thermal regulation, maybe it is not working correctly.
Schumacher chargers are typically cyclic like Battery Doc.
Your voltage measurements indicate the charger modes and voltages may be too low for AGM. The charger should deliver at least up to the 14,2 - 14,4V range and then maintain it at around 13,5 to 13,7V. Some chargers, like OptiMate 3 or 4 have a maintenance mode that does the rest bit automatically, during every hour of storage or maintenance charging they maintain for 30 minutes, then allow the battery to rest for 30 minutes, The cycle repeats until you disconnect the battery.
Others chargers are cyclic, like CTEK, Scumacher, Battery Doc (I think, based on article) and these can be cycled around to each battery, but no need to wait for the battery to discharge.
Something important to note about lead-acid batteries (std, AGM, GEL what-ever), they will last for many many years if kept at a perfect 100% charge as much as possible and never cycled / drained below 50% of charge. Think of your car battery, used every day, always charged whilst you are driving because of this usually lasts 4 years or more, or, until that moment you left the lights on or something like that and once recharged it usually is never the same again.
BTW I am lazy, don't want to run around and do the cycling the charger between bikes etc., so I have a number of OptiMates in my garage, on my bikes, on my cordless trimmer and blower. Both cordless tools 4 and 5 years old respectively and still working fine, oldest bike - just sold to a friend - 2004 suzuki Vstrom 650 with original battery. Gave him the OptiMate for the bike too.

Martin, thanks very much for the information and advice.

One of my concerns is with the AGM battery that discharged well below 50%. Apparently there are several parasitic draws on the battery on a Spyder, so charging is essential if stored for (I'm guessing) a month or longer without running.

Since the original battery failed within less than a month, I had assumed the replacement battery had also failed. But the dealer tech tested it, and said it was OK, just discharged. I've had it on the charger ever since, but I've left the Odyssey in the machine. The Odyssey is slightly smaller and with a slightly less capacity, but it seems to start the engine just fine.

I like to charge the batteries via a pigtail from the battery, making it easy to plug in either an SAE or molex connector, which also serves as power source for vest, GPS, etc. since it's hot battery.

I was somewhat surprised at the comparatively low charge rate for the "automatic" chargers I have. If the chargers are actualy cyclic, it's possible they are not actually charging when I'm making the voltage measurement, and what I'm measuring is battery voltage, not charger voltage. Can we expect that a fully charged battery will rest at 12.5V?

pmdave

I'm apparently in the process of re-educating myself about batteries and chargers.

I stumbled upon a site that has a LOT of information on the subject:
http://jgdarden.com/batteryfaq/carfaq9.htm#stages

I've just ordered a Tecmate Optimate 4 charger from www.smartchargers.com
(US$ 69.90; free shipping).

pmdave

Here's the test for a battery dealer (Odyssey) to determine the state of a questionable battery:

http://www.batterysales.com/pdf/Odyssey-Battery-Testing-Procedures.pdf

pmdave

pmdave said:

I'm apparently in the process of re-educating myself about batteries and chargers.

I stumbled upon a site that has a LOT of information on the subject:
http://jgdarden.com/batteryfaq/carfaq9.htm#stages

I've just ordered a Tecmate Optimate 4 charger from www.smartchargers.com
(US$ 69.90; free shipping).

pmdave

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Dave, that charger is only 0.8A, while a BT Plus is 1.0A, and a Jr. is 0.75A. Most of the issues known with the BT is whether they are a Jr or a Plus, as the Jr cannot output enough for charging an Odyssey battery. This same conversion is going on here.

Certainly this thread has been very informative to anyone wanting to know more about batteries and charging! The Odyssey battery test methods are widely used by other manufacturers too, especially the 1/2 CCA one when a load tester is used. For those armed only with a voltmeter and the bike itself ....
Rest voltage of batteries at 68 F / 20 C around 12 hours after recharging (too allow battery to cool to room temperature) are typically as follows: (can be found on manufacturer sites too).
STD filler cap (wet cell): 90-100%: 12,50 - 12,60V. 75% - 90%: 12,40 to 12,50V. Below 12,40V - problems!!
AGM (in general all are relatively similar except for 100% charged voltages): 90%-100%: 12,70 - 12,90V. 75%-90%; 12,60 - 12,70V. Below 12,60V, expect problems soon (unless it is the charger causing the problem, then get one to recharge it to the correct levels)!
Of course voltage measurements are a reasonble indication of battery health & state of charge, in the end it is the crank test that counts most. Simple test: Ignition key on, killswitch OFF. Crank the engine. If the cranking starts slowing within 15 seconds, you have problems! The longer it can crank (30 sec plus is my safe level) before the sound changes (cranking slows), the better. Below 60F / 15C expect shorter times. The lower the test temperature, the shorter ....

About Odyssey batteries

I've done many tests on Odyssey batteries - As long as the battery is in good condition any charger delivering the correct maintenance voltage (13,5V to 13,7V) during storage / maintenance charging and that can deliver at least 0,05C (500mA for a 10Ah battery) will maintain it.
That means: A typical 'junior' or plug in charger of any manufacturer is 2 stage is good for maintaining batteries that are in good health as long as the maintenance float charge level is in the range above.

It is when the Odyssey battery becomes deep discharged / partially sulfated that you need a charger delivering current of at least 1/3C and that has an absorption mode delivering at least 14,5V ro up to 14,7V or a cyclic charger that drives the voltage up to that level continuously (pulsing), to bring that battery back towards 100%. So, if you want 'insurance', buy the high current charger.

Popular Odyssey motorcycle models typically range between 12 and 16Ah, so you'll need a charger delivering (min.) 4 to 5A. Problem is, you cannot charge through canBUS, limit is 5A. So, a direct connect pigtail is your only option for on bike charging. (Don't recommend charging with battery clips, if the positive clip accidentally touches the vehicle body whilst connected to the battery ........ ).

I can say with pride that my methods of battery maintenance have resulted in batteries lasting from 9 to well over 16 years. The 16 year old battery started a car down to -30C, so its not like it had an easy life.

Now you all have something to aim for.

Try that in the heat we have. Optima and Odyssey batteries all are replaced halfway through their warranties and OEM batteries last 11-13 months.

rambrookian said:

I had planned on purchasing a new Odyssey PC680 this Spring for my 2000RT, as well as an Accumate Pro 7amp charger. Since I already have one BTP charger plus their BMW Gel version, I figured that I could use this new charger on ALL of my vehicle batteries... irregardless of battery type. However, MartinRSA's raises an important point about the 5amp CanBUS limit. Will the 7amp Accumate Pro fry the RT's electrical system?

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no concern, as your 2000 RT is pre-CANBUS. that system did not come into play until the 2005+ bikes

Battery question

What is the life span for a BMW gell cell? mine was installed in May 07 so it is nearly 3 years old.
It appears that it will not take a charge.

Will the Odessey PC 680 fit in an 2002 R1150 RT? What is a good source ( price ) for the Odessey?

Thanks Don in Mystic, CT

this may not be the lowest price available, but it is definitely a damn good one.
http://www.portablepower.com/odyssey...2042436f53b966
at checkout, you'll see that it's another $25 less than posted. shipping is gonna add about $20 of that back in. Still a hell of a deal.

and if you do a simple google search on "odyssey batteries", you'll find the application chart:
http://odysseybatteries.com/applications/motorcycles.htm

(yes, it's the PC680 for the RT)