Battery charging issue

I got tired of trying to select a charger a few years back. I bought a 30V 10A programmable power supply. When I need to charge a battery--car, motorcycle or boat--I simply look up the temperature-corrected charging and float voltages and set a timer on my phone. So far it's recovered a PC680 in 6 discharge/recharge cycles in one case and a year later recharged the completely dead 28V battery bank in a 50' lobster boat (a neighbor's) when its ecu drained it while sitting for a month.

rxcrider said:

Any idea why it would stop at 14.4 for the FLA and 14.7 for the Odyssey AGM if they don't have some sort of logic in it? Batteries were charged back to back on the same day and temperature was nearly the same, maybe a touch cooler when charging the FLA. I went back to the Odyssey after the FLA and it went to 14.7 again. Could they just be watching for the voltage to spike and at a certain rate of increase, they select a cut off point?

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No idea yet. I'll see if I can borrow one and put my data logger on it while charging a FLA and AGM. That'll be a winter project.

Here is a good one from Battery Tender which is why I have so little faith in anything from them, not to mention they are ultra vague when it comes to specs.

Looking up the Battery Tender Plus which is what you have, the last line states: "Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell)".

Yet they produce a Battery Tender Plus GEL. And on their Technical Info page they state that a GEL requires a reduced voltage (which is why I see a maximum of 14.2V on my R1150 GSA and usually less at 14.0V...voltage measured at the battery). Mind you, the most I have seen on my R1200 GSA LC is 14.1V indicated (14.3V max at the battery) and it has a YUASA AGM.

akbeemer said:

Not letting an excessive quest for perfection get in the way of good enough.

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Kevin as I already mentioned, any battery charger/maintainer, provided it does not overcharge the battery, is better than not using one at all.

And right from the Battery Tender site which is what I also posted earlier in response to a poster who claimed some chargers did not charge his battery where another charger did. Just something to keep in mind since users never read the instructions.

WORKING WITH A DEAD BATTERY OR A BATTERY WITH A VERY LOW VOLTAGE:
If you try to charge a dead battery having a voltage below 3 Volts, the Battery Tender®Plus charger will not start.

Click to expand...

And other brand of chargers may not work at higher voltages. You need a DC power supply attached to the battery to bring them up to a level high enough for the charger to work.

roger 04 rt said:

I bought a 30V 10A programmable power supply.

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Roger, what make and model is it?

I lucked into a mint HP lab grade 40V 10A power supply that I got on ebay. I use it often as well, but it isn't programmable (maybe it has an HPIB port...I never checked).

Battery Tender chat window conversation from this morning - sticking to their story:

→ On the Plus charger, can you tell me how it selects the voltage at which bulk charging stops and it goes into the absorption step?

Loretta: The micro processor determines which type battery it is connected to.

→Can you tell me how?

Loretta: It has to reach about 14.4-14.9 volts before it goes to absorption

Loretta: How The micro processor works?

→That I get, I'm trying to understand how it knows what battery it is hooked to and what voltage to select in the 14.4 - 14.9 range aside from temperature.

→missed your one comment - yes, how the micro-processor works

Loretta: You may submit an email requesting specific information and we will get it to our engineering department. Some of this information is proprietary.

Loretta: service@batterytender.com

→ok - thank you

Loretta: You're welcome
_______________________________________________________________

Off goes the email:

Per a chat window conversation this morning, please forward this question to engineering.

I have work on a fair number of motorcycles, mostly BMWs from the '90s with a mix of FLA, Gel (BMW / Panasonic), and AGM (Odyssey, Westco...) batteries. I've had two chat window conversations with Batttery Tender representatives regarding the Junior and Plus (My Plus is ~10 years old). In both, it has been stated that the microprocessor determines the type of battery it is connected to and sets peak voltage for the bulk charge and maintained voltage for the absorption step accordingly. (ignoring temperature compensation since it doesn't apply to the Junior). Without getting into proprietary details such as the actual values you use to make the determination, I'd like to know the following:

1) What parameters are you looking at to determine the type of battery / the peak voltage for the bulk charge and maintained voltage for the absorption step? Is this all done during the initialization step?

2) If you are adjusting the charging voltage, why float at 13.2V regardless of battery type?

3) Why is there a standard Plus charger and a Plus Gel? If you are able to determine the battery type and adjust your charging algorithm accordingly, why not cover all common lead acid battery types with a single charger?

4) Your product descriptions refer to a 4 step charging algorithm. Your technical section on your web site talks about a 5 step algorithm which includes an optional equalization step. Do any of your chargers offer the equalization step? If so, what is the voltage held at during equalization?

Thanks for your time - Jonathan

rxcrider said:

Some of this information is proprietary.

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That is such BS. I got that reply some time ago asking them about their charge algorithms because at the time, their specs were a joke and not much better now. Puck, all I have to do is connect my data logger which I have done for both my CTEKs ad Optimates to see what the charge algorithms are doing.

Notice how they didn't answer most of your questions. These things are made off shore to a price point. You should have seen the inside oh my CTEK. Fancy outside but the inside was not much to write home about.

I'll withhold judgement until I get the engineering response. I haven't opened my charger up (nor am I sure what it would teach me), but there is plenty of stuff they could monitor before and during charging to adjust their targets. This assumes they have done enough development work to determine which measurable characteristics they can use to somewhat reliably determine what their targets should be. I'll be curious to see if I get a response that makes sense. Maybe then I'll pop it apart and we can see if there are enough components to support their claims.

GlobalRider said:

Roger, what make and model is it?

I lucked into a mint HP lab grade 40V 10A power supply that I got on ebay. I use it often as well, but it isn't programmable (maybe it has an HPIB port...I never checked).

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I don't have the make & model with me but it's a generic that I got on amazon.

I should have said adjustable switching supply with voltage/limit, current/limt with fine/coarse for each--it's not literally programmable. It's my second unit, the first was a linear supply that I blew up after reversing the polarity for a second time.

It takes some care and feeding but it's worth it for me.

rxcrider said:

I'll be curious to see if I get a response that makes sense.

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So am I.

When I was working in the lab testing & evaluating chargers, one company made the same claims. It simply did not work as claimed.

Besides, if a charger can tell what battery it is hooked up to, Xantrex would have done so. Instead, the user has to select the type of battery on the touch panel, that it is connected to.

We had all the big names lent to us: Schumacher, PulseTech, Midtronics, etc. for evaluation. Simply incredible what they were trying to sell to us at defense and the $$$ they were charging.

Maybe there is just a lot of variability in what the battery tender does. Or maybe you need to hook up the battery first and then plug it in for it to do its thing. (Whatever that is)

I tried it again on the Odyssey and it repeated topping out at 14.7 V.
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Then I went to the FLA battery (Yuasa 51913) without unplugging the tender from the wall and it topped out at 14.6 V.
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I went back to the Odyssey (again without unplugging it from the wall) and got 14.6 V this time.
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I unplugged it from the wall and switched to another FLA (East Penn U1 tractor battery) and it:
- climbed steadily to 14.2 and was still hanging there for a half hour when I had to leave
(I wasn't paying attendtion to order on this one so not sure if the battery or wall plug was connected first)
- came back an hour later and it was in float at 13.1V - guess we'll do this again...

(This is is not the best battery in the world. For being only 2 years old, it doesn't do too well on the 100A load test, dropping to just under 10V after a few seconds, just a day or two after coming off the battery tender. This one may be a good test to see if the Optimate can really work magic.)

I unhooked the battery and unplugged the tender. I hit the battery with the 100A tester, then let it sit for a couple minutes. That dragged it back to 12.5V. Now I'll start over again...
- Plug in the battery, then the tender
- Climbed steadily to 14.3 in bulk and then dropped to 14.2 and I can hear it gassing.
- It went back up to 14.3 as it switched to absorption and then up to 14.4 and I can still hear it bubbling away.
- And now bubbling down to 14.3.
- And after 2 hours, it went into float, the bubbles began to subside and voltage slowly dropped to 13.2 after 5 minutes.
- After sitting for 20 minutes, I hit it with the load tester again and it held at 10.5V under load. 10 minutes later it had bounced back to 12.6V.
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For giggles - lets jump back to the Yuasa at 12.4V.
- hook up battery, then plug into wall outlet
- voltage climbed briskly and the battery started to gas at 13.9V
-within a couple minutes, voltage peaked at 14.4 and the tender switched into absorption, still at 14.4V.
- Stayed in absorption, slowly bubbling at 14.4V for an hour at which point I disconnected it.
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I disconnected the tender from the Yuasa and hooked it up to the 12.9V Odyssey without unplugging the tender from the wall.
- It went quickly to 14.4V in bulk mode and switched to absorption at 14.4V

I unplugged the tender from the wall and disconnected it from the Odyssey as well
- put 100A load tester on the odyssey for 10 count
- voltage recovered to 12.8
- reconnect to tender to Odyssey, then plug into wall.
- bulk charge voltage climbed steadily, peaking at 14.4 then switching to absorption.
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I unplugged everything and tried it on a smaller AGM (Everstart / Johnson Control ES9BS)
- hook up battery, then plug into outlet
- started gassing around 14V and it peaked at 14.40, then switched to absorption at the same voltage. It was late so I unplugged it and put it back in the bike without waiting for it to go into float.

______________________________________________________________________________

I'm dumbfounded by their supersmart charging. It almost seems like it randomly changes the charging voltage; whatever they are sensing certainly isn't foolproof. If you keep it plugged in and swap batteries, it appears to keep going with the settings from the previous battery. Alternatively, I guess their voltage regulation could just really stink and it can end up anywhere in the 14.4V - 14.9V range, but it seems to like 14.4 & 14.7 and then a float setting of 13.2.

Side note: The battery tender SAE plug volt meter seems to read a bit low or maybe just not round up. When it reports 14.6, I've seen my Fluke display as high as 14.67.
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2016-09-28:
Optimate 7 select delivered and I picked up a couple U1 riding mower batteries that have been sitting at under 5 volts for a day in one case and for a few weeks in the other. Let the games begin.

After using it to trick the optimate into charging battery #1 below, I put the FLA Yuasa 51913 on the load tester at 13.1V. It ran 10V @ 100A (at least in terms of what it is rated for current draw, not measured) and then popped back to 12.4. I put it on the battery tender and left it for a while as voltage slowly climbed. When I noticed it in absorption, it was at 14.5V and climbed to 14.6V while I watched; so much for steady voltage. After over an hour, it was still gassing away in absorption and back down to 14.5V. After ~1.5 hours it went into float at 13.3V. I disconnected it and after a minute, it was still showing 13.2V.

Odyssey at 12.9V
10.6V on the 100A tester
Then back to 12.7V
Hook up to battery tender, then plug it in
8:43pm 13V
8:50pm 13.5V
9:19pm 14.5V in absorption
9:34pm 13.2V in float

That is enough playing with the Battery Tender Plus. It does stuff, but who knows what, when, why or for how long. Maybe the engineering department that hasn't responded to my email.

Battery #1
East Penn U1 150 CCA
Went to the scrap bin yesterday, but maybe it has been sitting discharged longer than that.
Built in March of 2015
-0.14V

Piggybacked on Yuasa 51913 to get optimate to recognize a battery present and start charging.

The pair clear the bulk mode and go into absorption in under 10 minutes.

disconnect everything

U1 at 12.48 V
That was too quick - can't be good
Reconnect to optimate by itself
Plug optimate in
Runs tests and diagnostic lights indicate a deeply discharged battery.

Optimate goes into save (NOT turbo save / desulfate) after initial tests
6:10pm 14.8V constant
6:27PM ~13 -16V pulsing @ ~1hz
7:11 pm ~13-15.5V pulsing @ ~1hz
8:10pm ~13-14.5V pulsing @ ~1hz
8:30pm ~13-15.5V pulsing @ ~1hz
8:45pm past the charge step and onto optimize: ~13-14.5V pulsing @ ~1/2-2hz
9:20pm ~13-14.5V pulsing @ ~1/2-2hz
11:11pm in float; rapid pulse ~13.2-13.6V
Diagnostic light indicates battery is capable of 60-80% of what it should be

Unplug optimate and then disconnect battery

12.7V
1V @ 100A load
Returns to 11.5V
Then slowly to 12.5V

That isn't 60-80%

I'll give it another go later
___________________________________

So the Optimate is looking for some resistance value to decide if it is hooked to a loose battery or one installed in a vehicle. If it thinks it is installed in a vehicle, it won't go into turbo save / desulfate mode, even if it thinks the battery needs it. I hooked it up again this morning without a volt meter attached in case I was impacting the charger's performance. We will see if can work miracles, but this battery really should be toast.

Home from work and once again, diagnostic light indicates battery is capable of 60-80% of what it should be

Unplug optimate and then disconnect battery

12.7V
3.5V @ 100A load
Returns to 11.7V
Then slowly to 12.5V

Calling it Kaput

Battery #2
East Penn U1 275 CCA
Built Nov 2010
6.49V

Hooked up battery & plugged in optimate

Test indicates deep discharge and into some sort of save mode it goes. We'll see what it does tomorrow.

The morning dawned on a flashing red light on one of the test indicator lights. I'm not sure if that means it is still testing or if it has failed miserably. I unhooked it and went back to battery #1 with the optimate. I'll read the manual again tonight and load test the battery.

Home from work and

10.4V
5V @ 100A load and bubbling
Returns to 8V

Flashing red during test period indicated that voltage was dropping rapidly.

Stick a fork in it.

Battery #3
East Penn U1 230 CCA
Built February 2015
12.45V
Drops to 10V with 100A load tester.
Not sure why this was on the scrap battery skid

5:05 pm Optimate says 40-60% charged and goes straight into charging

6:30pm in optimize mode

7:07 flashing green test light for 30 minute voltage decay test. Battery at 13.0V

7:39 solid green indicator for good battery
Had already started float cycle so voltage is up above 13 and slowly falling
10.6V @ 100A
Recovers quickly to 12.6V
Charged up nicely

Battery #4
Yuasa 51913 FLA
This one will give me a comparison against the battery tender.

9/28: After using it to trick the optimate into charging battery #1 above, I put the FLA Yuasa 51913 on the load tester at 13.1V. It ran 10V @ 100A (at least in terms of what it is rated for current draw, not measured) and then popped back to 12.4. I put it on the battery tender and left it for a while as voltage slowly climbed. When I noticed it in absorption, it was at 14.5V and climbed to 14.6V while I watched; so much for steady voltage. After over an hour, it was still gassing away in absorption and back down to 14.5V. After ~1.5 hours it went into float at 13.3V. I disconnected it and after a minute, it was still showing 13.2V.
-----------
9/29 7:00pm:
12.5V
10V @ 100A on load tester
Came back to 12.2V quickly

7:48pm: Optimate indicates a weak battery @40-60% charge and goes straight to charge w/some gassing, but significantly less than battery tender.

9:07pm: the Optimate is optimizing w/ the occasional bubble still rising up.

9:43pm: flashing green for good battery in 30 minute decay test. 13.0V

9:52pm: solid green for good battery- disconnect and let it sit to load test tomorrow. 13.2V

9/30 3:50pm:
12.5V
10V @ 100A on load tester
Came back to 12.3V quickly

Essentially the same result as the battery tender which is ok for a used FLA battery pulled out of a bike for replacement because it cranked slowly at times.

Battery #5
Odyssey PC680

9/28 on the battery tender
12.9V
10.6V on the 100A tester
Then back to 12.7V
Hook up to battery tender, then plug it in
8:43pm 13V
8:50pm 13.5V
9:19pm 14.5V in absorption
9:34pm 13.2V in float and time to disconnect it
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9/29 @9:52pm:
12.9V
10.8V @ 100A
Recovered to 12.7V quickly
Set optimate to 14.7V and hook up.
Optimate indicates a good battery and goes into charge mode.

10:50pm: optimize mode

10:54pm: flashing green in 30 minute decay test.

11:42pm: green light for a good battery in float charge mode. Disconnect and let it sit 'til tomorrow for a load test. 13.2V

9/30 3:57pm:
13.0V
10.8V @ 100A
Recovered quickly to 12.7V

Again, no better than the battery tender. If it is truly better at long term storage / float charging on an AGM, I have no intention of finding out.

Here is the email I sent to Battery Tender and their response.
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My email:

Per a chat window conversation this morning, please forward this question to engineering.

I have work on a fair number of motorcycles, mostly BMWs from the '90s with a mix of FLA, Gel (BMW / Panasonic), and AGM (Odyssey, Westco...) batteries. I've had two chat window conversations with Batttery Tender representatives regarding the Junior and Plus (My Plus is ~10 years old). In both, it has been stated that the microprocessor determines the type of battery it is connected to and sets peak voltage for the bulk charge and maintained voltage for the absorption step accordingly. (ignoring temperature compensation since it doesn't apply to the Junior). Without getting into proprietary details such as the actual values you use to make the determination, I'd like to know the following:

1) What parameters are you looking at to determine the type of battery / the peak voltage for the bulk charge and maintained voltage for the absorption step? Is this all done during the initialization step?

2) If you are adjusting the charging voltage, why float at 13.2V regardless of battery type?

3) Why is there a standard Plus charger and a Plus Gel? If you are able to determine the battery type and adjust your charging algorithm accordingly, why not cover all common lead acid battery types with a single charger?

4) Your product descriptions refer to a 4 step charging algorithm. Your technical section on your web site talks about a 5 step algorithm which includes an optional equalization step. Do any of your chargers offer the equalization step? If so, what is the voltage held at during equalization?

Thanks for your time - Jonathan
-------------------
Their response:

This is the response from our engineering department.

There is a misunderstanding that chargers have the ability to determine battery chemistry and/or type of lead acid battery. Our chargers cannot do that nor can anybody else’s. Electrically, each type of lead acid battery looks virtually identical to the others. What we do is make compromises so that we can do a good job charging a battery no matter what type lead acid it is. This allows a hook it up and forget it experience for the customer. This eliminates questions 1) through 3). Question 4) only applies to the AGM setting of the DVD-40 and all golf cart type chargers except the Emergency Vehicle charger. These chargers have an additional stage to equalize the charge of each battery cell. The maximum voltage of this stage is 15.7V with a current limit around 2 amps.

Thank you,

Loretta
Deltran USA, LLC
801 International Speedway Blvd.
DeLand FL 32724

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So there you have it. An honest answer from Battery Tender engineering which contradicts the myth perpetuated by customer service / sales.

I think I've run away with this thread long enough. Both the 10 year old battery tender plus and the latest Optimate 7 select can charge a battery. They go about things a bit differently and the Optimate should run quicker on larger batteries, but the are both capable. Neither of them can work outright miracles. Despite being capable of running 10A, (in theory at least) The Optimate appears to do a good job of turning down the flow for small batteries based on the reduction in gassing and long charge times. If the Optimate can last as long as my Battery Tender, I'll be perfectly happy with both purchases.

m_stock10506 said:

The OP says his bike is an R1100RSL. These battery replacement steps sound just like the steps for my RT. Are these steps the same for an RS? Similar enough?

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The RT has a snorkel that unhooks at the front whereas the other models need to be unscrewed. That's the only difference I can think of.

rxcrider said:

There is a misunderstanding that chargers have the ability to determine battery chemistry and/or type of lead acid battery. Our chargers cannot do that nor can anybody else’s.

Loretta
Deltran USA, LLC

--------------------------
So there you have it. An honest answer from Battery Tender engineering which contradicts the myth perpetuated by customer service / sales.

Click to expand...

Bingo, exactly what I said and what we told these marketing people passing BS when I worked in the lab evaluating chargers.

BTW, your battery should not "gas" if you stay under the voltage cut-off for the battery unless it is defective. This is a per-cell voltage which you can multiply by the number of cells to get your end voltage. Of course if the cells need balancing, you'll need to go over-voltage and some cells will gas. You simply top off the cells with distilled and you are set again. As mentioned before, the Xantrex will not allow you to go into equalization mode on an AGM or GEL for that reason.

GlobalRider said:

BTW, your battery should not "gas" if you stay under the voltage cut-off for the battery unless it is defective...

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Pretty much the case on the batteries which were gassing. They have all been replaced in service but serve purposes like emergency spare or the power supply for my fuel transfer pump.



Sent from my iPhone using Tapatalk

PGlaves said:

I admire Global Rider's expertise in his area. I truly do. But i am a pragtimist. I have Schumacker chargers. I have Battery Tender Chargers. I have several other brands. I have about 10 such devices. NONE are optimal. I just try to keep 9 motorcycles and three 4 wheelers running, and starting. I can't afford $150-$160 chargers. So I try to keep stuff ready to start. Sometimes it is gold - sometimes it is @#$$%. Such is life. If I had one bike or one car then I might try to find the optimum. Otherwise, I look for adequate. Will it start?????

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+1 on Expertise and thank you GlobalRider! +1 on avoiding unecessary Battery Charger cost. Batteries are extremely costly as well. Since I only have two vehicles to care for over winter (my R1200RT - Odessey PC680, my son #2 4WD Rally Turbo Celica car - Odessey PC680) and the fact that I am home most of winter I can get by with one charger and swap it around as needed. On both vehicles I tried Battery Tender versions and this led to premature no start conditions after three years of Battery Tender Odessey winter charging on both the bike and the car. Then I had to replace both the batteries more than once.

Due to GlobalRider and this forum I heard the CTEK Multi US 7002. It is the perfect battery charger for my situation balancing both the cost of battery chargers, effectiveness of the charging long term and the cost of premature battery replacement. I am currently using it to bring another PC680 back from the dead for son #1 who found he had a persistent drain in his rally car over this winter that already flattened his battery (5.9V) after at two week -25C two week cold snap which may have also froze the battery.

Why are my kids using PC680's in their cars? They have so much stuff packed into the engine compartments there is literally no room for a conventional battery.

Thanks all for this excellent information, help and updates via the forum.