A good $4.99 battery tender/charger

[Cruizin]

With winter coming I thought I'd share this $4.99 battery tender. I paid full price a couple years ago for one of these and it works great, used it last two winters and the batteries were in tip top shape in the spring. Motocentric Battery Tender/charger

[DavidS]

and type in code "fs-thx-153" for free shipping

[2and3cylinders]

Whereas it may work OK, optimum charing is achieved for most motorcycle batteries at 1.25 amps at 14.45 volts, so this charger is providing only half the prescribed amperage

[Cruizin]

Yet somehow my battery is in tip top shape. I just bought five more for christmas presents for some friends.

[wessie]

Whereas it may work OK, optimum charing is achieved for most motorcycle batteries at 1.25 amps at 14.45 volts, so this charger is providing only half the prescribed amperage

I suggest you read http://jgdarden.com/batteryfaq/carfaq9.htm#equalization and the rest of http://www.batteryfaq.org/  
Ideal battery charging is a combination of current limited charging, constant voltage charging and fixed current charging - that website has some typical charging algorithms used by smart chargers. 
 
Here's one for an AGM battery as fitted to the FJ09

 
You will note that only 2 hours of the 16 hour cycle is at a fixed current. The figures, using 10A as the current limit are for a heavy duty car charger. 
 
A 750mA charger is fine for motorcycle batteries - it would struggle to charge a large battery from a diesel car or petrol V8 as it will probably go into float mode before it has added enough electrons. 
 
If you look at the Ctek range of chargers, probably the best chargers for the home & professional user, they start with a 800mA charger for motorcycles. 

[zachd]

Thanks Cruizin...picked one up. The free shipping coupon code definitely helped the purchase too, thanks David!

[2and3cylinders]

Whereas it may work OK, optimum charing is achieved for most motorcycle batteries at 1.25 amps at 14.45 volts, so this charger is providing only half the prescribed amperage

I suggest you read http://jgdarden.com/batteryfaq/carfaq9.htm#equalization and the rest of http://www.batteryfaq.org/  
Ideal battery charging is a combination of current limited charging, constant voltage charging and fixed current charging - that website has some typical charging algorithms used by smart chargers. 
 
Here's one for an AGM battery as fitted to the FJ09

 
You will note that only 2 hours of the 16 hour cycle is at a fixed current. The figures, using 10A as the current limit are for a heavy duty car charger. 
 
A 750mA charger is fine for motorcycle batteries - it would struggle to charge a large battery from a diesel car or petrol V8 as it will probably go into float mode before it has added enough electrons. 
 
If you look at the Ctek range of chargers, probably the best chargers for the home & professional user, they start with a 800mA charger for motorcycles. 
 
 
 
Yes I agree and understand the science of battery charging.  What I was trying to convey is that optimum motorcycle battery charging typically requires a minimum of 1.25 amps which the charger in question cannot provide (it's rated at .75 amps).
 
Also, I prefer brand name chargers made by Deltran (http://www.batterytender.com/Frequently-Asked-Questions/#answer4) and Tecmate (http://tecmate.com/products/optimate5/)

 

[megroovy]

personally I just stick a small solar panel on the roof of the garage. does the job for me.

[oldfart]

I'm not sure whether I enjoyed this page about the science of battery charging (Not to be confused with tending) more than I enjoyed the two pages about whether the FJ-09 is best fueled on the side stand or center stand. Hmmmmm.....

[wessie]

I suggest you read http://jgdarden.com/batteryfaq/carfaq9.htm#equalization and the rest of http://www.batteryfaq.org/  
Ideal battery charging is a combination of current limited charging, constant voltage charging and fixed current charging - that website has some typical charging algorithms used by smart chargers. 
 
Here's one for an AGM battery as fitted to the FJ09

 
You will note that only 2 hours of the 16 hour cycle is at a fixed current. The figures, using 10A as the current limit are for a heavy duty car charger. 
 
A 750mA charger is fine for motorcycle batteries - it would struggle to charge a large battery from a diesel car or petrol V8 as it will probably go into float mode before it has added enough electrons. 
 
If you look at the Ctek range of chargers, probably the best chargers for the home & professional user, they start with a 800mA charger for motorcycles. 

 
 
Yes I agree and understand the science of battery charging.  What I was trying to convey is that optimum motorcycle battery charging typically requires a minimum of 1.25 amps which the charger in question cannot provide (it's rated at .75 amps).
 
Also, I prefer brand name chargers made by Deltran (http://www.batterytender.com/Frequently-Asked-Questions/#answer4) and Tecmate (http://tecmate.com/products/optimate5/)

 
I have corrected the cocked up formatting in your post.
 
I don't suppose anyone buying a $5 charger worries about optimum charging. All they want is for some electrons from the national grid to be transferred into their battery and the will sleep just the same if they trickle in at 750mA or romp in at 1250mA. The number of electrons stored is finite so after a few hours, current inflow will be 0mA.