Group 94R AGM battery/CTEK 3300 How to Charge?

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1,935
Location
British Columbia, Canada
I have a Motomaster Eliminator Ultra AGM Group 94R (L4/H7) battery and a CTEK Multi Us 3300 4 step charger. I like to charge the battery periodically if I haven't been driving my BMW very much.

The battery charger has 3 settings: Motorcycle 14.4V/0.8A; Auto 14.4V//3.3A; and AGM/Cold Temp 14.7V/3.3A.

The CTEK instructions are vague about whether to use the AGM cycle for all AGM batteries and suggest consulting the manufacturer. Good luck consulting Canadian Tire with a technical question.

Battery experts - Which setting should I use? Auto (14.4 V/3.3A) or AGM (14.7 V/3.3A)
 

ecotourist

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1,935
Location
British Columbia, Canada
Thanks UncleDave.

The CTEK Manual says ".... recommended for many AGM batteries like Optima, Maxxima and Odysses. Consult your battery manufacturer when in doubt." Our battery doesn't look like an Optima battery. Maxxima seems to be a British Exide brand. And I haven't found any Odysses brand batteries (though there is an Odyssey brand manufactured by Enersys - which I've never heard of either). The photos of none of these batteries look even remotely like our battery.

My concern is harming the battery by charging it too much.
 
Messages
4,277
Location
Ca.
Thanks UncleDave.

The CTEK Manual says ".... recommended for many AGM batteries like Optima, Maxxima and Odysses. Consult your battery manufacturer when in doubt." Our battery doesn't look like an Optima battery. Maxxima seems to be a British Exide brand. And I haven't found any Odysses brand batteries (though there is an Odyssey brand manufactured by Enersys - which I've never heard of either). The photos of none of these batteries look even remotely like our battery.

My concern is harming the battery by charging it too much.

I have several Odysseys - best Ive owned. Ive got an 11 year old one in my titan now.

Barring any other info from the mfgr, and it is an AGM, 14.4 is a slight undercharge.

IF you want to play it safe and will never need the few 10nth undercharge it.
 
Messages
1,212
Location
Ontario, Canada
I have a Motomaster Eliminator Ultra AGM Group 94R (L4/H7) battery and a CTEK Multi Us 3300 4 step charger. I like to charge the battery periodically if I haven't been driving my BMW very much.
The battery charger has 3 settings: Motorcycle 14.4V/0.8A; Auto 14.4V//3.3A; and AGM/Cold Temp 14.7V/3.3A.
The CTEK instructions are vague about whether to use the AGM cycle for all AGM batteries and suggest consulting the manufacturer. Good luck consulting Canadian Tire with a technical question.
Battery experts - Which setting should I use? Auto (14.4 V/3.3A) or AGM (14.7 V/3.3A)
I have the very same CTEK, you could use the regular car battery setting for an AGM, but why would you? It would take a LOT longer to charge and may never get to a full charge, whereas the Cold/AGM setting can be used when the temperature is cold on a regular battery and recommended on AGM as it charges faster at a higher rate.
 

ecotourist

Thread starter
Messages
1,935
Location
British Columbia, Canada
I have the very same CTEK, you could use the regular car battery setting for an AGM, but why would you? It would take a LOT longer to charge and may never get to a full charge, whereas the Cold/AGM setting can be used when the temperature is cold on a regular battery and recommended on AGM as it charges faster at a higher rate.
The only thing holding me back is that odd little caution in the manual. And I know of no way to identify the manufacturer of my Canadian Tire battery to ask.

It would be nice to know why using the AGM setting would be an issue for any AGM battery. All things considered I probably should use the AGM setting.
 
Last edited:
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1,065
Location
Arizona
I beleive the AGM will be just fine to use. A Smart charger has algorithms that define the charging strategy by the tech in use. Initial voltage, charge ramp/rate and finish voltages will be similar between AGM's. Warnings telling you not to use the charger to pound in nails and check you manufacturer is just to release them of responsibility if something odd happens.
 

ecotourist

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1,935
Location
British Columbia, Canada
I beleive the AGM will be just fine to use. A Smart charger has algorithms that define the charging strategy by the tech in use. Initial voltage, charge ramp/rate and finish voltages will be similar between AGM's. Warnings telling you not to use the charger to pound in nails and check you manufacturer is just to release them of responsibility if something odd happens.
Probably right. Just a little CYA comment.
 
Messages
4,277
Location
Ca.
I have the very same CTEK, you could use the regular car battery setting for an AGM, but why would you? It would take a LOT longer to charge and may never get to a full charge, whereas the Cold/AGM setting can be used when the temperature is cold on a regular battery and recommended on AGM as it charges faster at a higher rate.

Using the regular setting will get it to 14.4 and show "fully charged".

- but it wont be -

fully charged is 14.7 so youll get a false green light.
 
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1,695
Location
Northeast Nebraska
I have the very same CTEK, you could use the regular car battery setting for an AGM, but why would you? It would take a LOT longer to charge and may never get to a full charge, whereas the Cold/AGM setting can be used when the temperature is cold on a regular battery and recommended on AGM as it charges faster at a higher rate.
I have an AGM from AA and a 4.3 Ctek and it is way faster using the AGM setting and only takes a couple hours to get to stage 7 compared to 15ish hours on Normal. I have never put a mulitmeter on it afterwards so not sure if it's charging it higher or not.

I'm just not sure if the AA AGM is considered a power AGM, here is a screen shot of my manual.

Capture.JPG
 

ecotourist

Thread starter
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1,935
Location
British Columbia, Canada
I have an AGM from AA and a 4.3 Ctek and it is way faster using the AGM setting and only takes a couple hours to get to stage 7 compared to 15ish hours on Normal. I have never put a mulitmeter on it afterwards so not sure if it's charging it higher or not.

I'm just not sure if the AA AGM is considered a power AGM, here is a screen shot of my manual.

View attachment 34244
The manual for my charger is similar to the first 3 categories you show but without the temperature range. My CTEK 3300 charger only has 4 steps.
 
Messages
3,231
Location
Idaho
I have a Motomaster Eliminator Ultra AGM Group 94R (L4/H7) battery and a CTEK Multi Us 3300 4 step charger. ........
Battery experts - Which setting should I use? Auto (14.4 V/3.3A) or AGM (14.7 V/3.3A)
If the battery is manufactured by East Penn, they recommend a optimum charging voltage of 14.4-14.6 @68F and a optimum float voltage of 13.5-13.8 @68F
If you want to charge at 14.7V, make sure the battery temperature is 60F or a little lower.
 
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