Just got a new AGM battery and......

[John Schmidt]

I need to know if a regular Battery Tender can be used on it. Anyone!

[old2soon]

           While I am Not sure about any charger my newer one from wally wurld do have a switch for A G M. I Know-not much help. RIDE SAFE.

[sandy]

Get a CTEK 3300 on Amazon.

[98valk]

AGM Type - Yes any battery charger can be used.

[Jess from VA]

John, I did a lot of reading on this, and the conclusion I came to (from the Yuasa instructions and website) was that a regular charger set to two amps (I think 1.5 amps was called for, but my charger, and most, only have trickle, 2, 10 and 50 amp settings) was best for the initial charge, for the time specified (I took a little time off going with 2 instead of 1.5 amps).  

Using one of my Battery Tender Jr's might have been OK, and it would just run (red led) until fully charged up (green led), but there was a real question as to whether this was the best way to do the all important first charge with new acid.  DO NOT stick those semi permanent (AGM) plugs in the cells until after that first charge.  It must breathe, and could explode (esp at 2 amps).  The fumes in my shed were pretty strong.

The charge rate on my BT Jr's is really tiny.

Maybe I worried for nothing.  I dunno.

[WintrSol]

If you never discharge the battery very low, a Battery Tender (1.5A or 750mA) will work just fine. It's when you take the battery down more than 1/2 way that you need a different charger. This is especially true of gel batteries, but AGM, being sealed, needs a different charger than your typical flooded battery.

[h13man]

I tried last spring using the BT Jr. to fulfill the charging need's for the new AGM Yuasa, not. Had to use my regular charger on 2 amp. setting. All is good.

[RonW]

I've been using Battery Tender Plus for years on AGM batteries. I'm sure Battery Tender would have mentioned something like, "Do not use on AGM batteries!!" Does it take longer? Dunno, it's the only charger I've used. Also, dunno if an AGM charger would have been that much faster to make it worth the extra money.

[Malkozaine]

I think Lithium Batteries are really the only ones that need a special charger outright.  I have used a Tender on a AGM before.  On that note anyone try a Lithium Battery in a Valkyrie yet?

[The emperor has no clothes]

I always thought the battery tenders were for just keeping the charge up on a bike that is going to sit a while. Not for charging. (I think hubcapsc put in one of those new fangled lithium things in a while back)

[98valk]

I think Lithium Batteries are really the only ones that need a special charger outright.  I have used a Tender on a AGM before.  On that note anyone try a Lithium Battery in a Valkyrie yet?

a charger that has a Desulfation mode Cannot be used for a LiFePO4.  any other charger can be used as long as voltage Does Not go above 14.6v, which most modern smart chargers do not.

I have this Bikemaster in the Valkyrie. 8lbs lighter
https://www.ebay.com/itm/BikeMaster-Lithium-Battery-Kawasaki-VN1500G-Vulcan-DLFP16-BS-780824-270-CCAMPS/352440127440

[WintrSol]

I tried last spring using the BT Jr. to fulfill the charging need's for the new AGM Yuasa, not. Had to use my regular charger on 2 amp. setting. All is good.

The battery probably came with less than about 50% charge, which is about 12.20V at the terminals (higher for a gel battery), after resting. When that low, a battery needs more of a boost to get the charge process going, which is something like 10% of the Ah rating, so 1.4A for the stock size Valkyrie battery.

I had the same issue with the flooded battery in my wife's car, which had drained until the lights had dimmed, maybe to 25% left. I had to use a big charger to get it going, then the 1.5A BT could finish it overnight.

[RonW]

I don't think 'AGM' and 'gel' shouldn't be used interchangeably. The letter 'G' in AGM stands for 'glass' ..... absorbent glass mat. Actually fiber-glass mat. I don't think AGM batteries even use gel.

[Jess from VA]

And a Battery Tender Plus charges at a higher rate than the Juniors.

I used to have both.  The Plus is the only one that ever crapped out on me, and all but one of my Juniors are over 10-12yrs old (and in nearly constant use).  The Plus came with one of my bikes, and was old when I got it. 

BT Plus: (1.25 Amp, and probably close enough to 1.5 for government work)


BT Jr: (.75 Amp)

[WintrSol]

I don't think 'AGM' and 'gel' shouldn't be used interchangeably. The letter 'G' in AGM stands for 'glass' ..... absorbent glass mat. Actually fiber-glass mat. I don't think AGM batteries even use gel.

Correct. Gel batteries behave differently than the other types, and have more restrictions on charge rates. Above 25% state of charge, the gel types have a consistently higher resting Voltage, they do not tolerate charge Voltage greater than 14.7V at standard temperature, and are more sensitive to temperature during charging, so a compensating charger should be used.
AGM are just regular liquid based batteries, with the liquid soaked into a fiber mat that is between the plates.

[h13man]

I tried last spring using the BT Jr. to fulfill the charging need's for the new AGM Yuasa, not. Had to use my regular charger on 2 amp. setting. All is good.

The battery probably came with less than about 50% charge, which is about 12.20V at the terminals (higher for a gel battery), after resting. When that low, a battery needs more of a boost to get the charge process going, which is something like 10% of the Ah rating, so 1.4A for the stock size Valkyrie battery.

I had the same issue with the flooded battery in my wife's car, which had drained until the lights had dimmed, maybe to 25% left. I had to use a big charger to get it going, then the 1.5A BT could finish it overnight.

The Yuasa came uncharged as the acid was shipped separate and yes its a AGM. Instructions said to use 1.4 amps for 10 hrs. if the memory serves me well ??? thus .75 amp didn't work thus the full charge with the 2 amp setting.

[98valk]

I don't think 'AGM' and 'gel' shouldn't be used interchangeably. The letter 'G' in AGM stands for 'glass' ..... absorbent glass mat. Actually fiber-glass mat. I don't think AGM batteries even use gel.

Correct. Gel batteries behave differently than the other types, and have more restrictions on charge rates. Above 25% state of charge, the gel types have a consistently higher resting Voltage, they do not tolerate charge Voltage greater than 14.7V at standard temperature, and are more sensitive to temperature during charging, so a compensating charger should be used.
AGM are just regular liquid based batteries, with the liquid soaked into a fiber mat that is between the plates.

yep, my charger has a separate switch to charge Gel batteries

[9Ball]

I need to know if a regular Battery Tender can be used on it. Anyone!

Are you asking about the initial charge or maintenance after the battery is charged and being stored over winter?

The answer is no, then yes.  The battery tender does not have sufficient amperage to charge a new battery after the acid is added.  You need something with a charge rate of 1.5-2 Amp hours for initial charging.

[John Schmidt]

Well, just so you all will know, I put my Battery Tender on it the afternoon I got the battery. By nightfall it was still a red light so I left it hooked up overnight. Next morning....green light. Installed it that afternoon and fired up the bike. Due to other responsibilities I've had to let the bike sit with the Tender plugged in. It cycles from green to red and back, depending on conditions. The one question I do have is this....will an AGM battery just go bad without warning? That's what the old battery did; one day it fired right up and ran fine, didn't have to grind on the starter for an extended period. This was after the bike sat for nearly a month while I worked on it. Two days later I wanted to take a ride and it was dead....did not have the Tender hooked up during that short period. It seemed so sudden which really surprised me.

[Jess from VA]

They usually don't go bad without some warning.  But it really depends on how long they sit with no use and no charger.  Long enough, and it may/will eventually die.

My bikes sit on Battery Tender Jrs 24 x 7 x 365 unless riding or traveling.  From my 200 amp circuit box to my outdoor GFCI circuits, to my 30amp dogbone, to my fusebox, and the fuse in each Tender, I don't worry about fires, and in many years I've never cooked a battery to death.

In decent riding weather and temps, and with perfect tune-ups, my bikes nearly always fire up (with choke) instantly.  Only in winter cold and sitting for weeks at a time (but still on Tenders) will they have to crank a bit to start.  But, after 5-6 years, in good warm weather with routine use, my bikes will eventually begin to need two, three long seconds of cranking to fire.  That's when I get a new battery (well, I always have a spare on hand, but no acid in it).

 

[9Ball]

If not charged initially at the rate listed on the battery you may not get much life out of that battery.  The initial charge is extremely important and a battery tender performing this function is not wise or recommended.

Good luck...

[hueco]

I have a Schumacher  trickle charger that works on my  AGM batteries.  Another Schumacher  3 amp, 5 amp, 20 amp and 75 start amp. Choice of standard ,agm and one other setting i can't remember.  Ride safe.

[WintrSol]

If not charged initially at the rate listed on the battery you may not get much life out of that battery.  The initial charge is extremely important and a battery tender performing this function is not wise or recommended.

Good luck...

Not the Battery Tender Jr, but the BT Plus should charge it just fine. This is discussed near the bottom of the FAQ page: http://www.batterytender.com/faq/products

[Jess from VA]

That's what I was trying to say above.  (with pictures)

[9Ball]

If not charged initially at the rate listed on the battery you may not get much life out of that battery.  The initial charge is extremely important and a battery tender performing this function is not wise or recommended.

Good luck...

Not the Battery Tender Jr, but the BT Plus should charge it just fine. This is discussed near the bottom of the FAdQ page: http://www.batterytender.com/faq/products

In accordance with the FAQ referenced, you are correct but there are a few conditions regarding the initial charge using a BT+ that in my opinion makes it a poor choice for this purpose.  The battery initialization chemistry requires sufficient Amps to complete the reaction.  Even if all the BT+ initial charge guidelines are followed, I would worry that the overall battery life will be negatively affected.  Per the BT+ FAQs and Qualification B...

For example, a 16 Ah battery will take about 13 hours to get to the absorption voltage (constant 14.4 Volts). It may take another 6 to 8 hours to reach the float voltage (constant 13.2 Volts). This may sound awkward; because what happens is that the battery charge current drops while the absorption voltage is held constant. When the battery current drops to 0.1 amp, or if 6 to hours have elapsed at the absorption voltage, the charger automatically switches its output from 14.4 V to 13.2 V. So it may take the better part of 20 hours to reach the float stage. Add another 24 hours to that and you are at 44 hours. Throw in another 4 hours for good measure and you get a nice round, even 48 hours, or 2 days.

Qualification B) Although there are probably several charging methods that will be equally effective, regardless of who manufactures the battery, in the interests of technical consistency, they will not officially sanction any initial charging method other than those published in their technical applications literature.

I have been using Battery Tenders for decades now.  I had one BT+ go bad just outside the warranty period and one BT Jr stop working.  All three of my bikes are currently resting on BT Jr tenders.  They provide a lot of bang for the buck.

Hope all works out.  I’ve only had one bad battery from Yuasa that didn’t take the initial charge and their customer service replaced it free of charge.  One of the best benefits of using a battery tender is the long life of the battery.  It’s not unusual to get 7 to 10 years out of a Yuasa battery that is maintained by a BT.

[98valk]

with a LiFePO4 battery, a tender is not needed, since the battery goes to sleep and doesn't discharge.  After 2-3 months of winter, all that is needed is turn the headlight on for a minute then shut off for a few minutes to wake it up. then start and ride.

[MarkT]

I follow the directions packed with the battery and use a manual NAPA cart-mounted manual charger for the time and amps required for the initial charge.  On a bike battery that is 2amps for 10 hours IIRC.  This one is also able to restore a sulfated battery - or even start a car/truck engine with up to 225 amps max power.  The rest of the time I use 6-amp max automated chargers.  They will put enough charge in a dead battery for it to start in 5 minutes or so.  This has been a good program for me.

[Mtn Valk]

Just swapped out my Yuasa battery for a new one (Yuasa). Emptied acid into cells, left cell cap strip off during initial charge at .9 amps, with my new Battery Minder Plus. Was fully charged after approximately 12 hrs. Replaced cell cap strip, placed in bike. Motor turns over rapidly now.
My old Yuasa began to show its age through last year with slower starts, then finally the battery succumbed to the cold. I also never used to keep a Battery Tender/Minder on my battery, but will do so now, if I don't plan riding for a week or longer.