Optima Blue Top Battery Charger

[jooleyen]

I bought an Optima Blue Top battery and I have a high speed charger. I heard these are bad for the blue top.

What specifications should I look for in a battery charger and what would you recommend?

Thanks

[zooker]

2 amp trickle charger it is what i use.. and have been using for 5 years now on my optima...

zooker

[nofearengineer]

There are some guidelines I read about as far as what size charger to get for any battery, where you divide the reserve capacity of the battery by a certain number to get the maximum charging amps for the battery.

I also have a blue top Optima, and the number for it was 6 (I can't find the webpage any more). Since the battery has a 120AH reserve capacity rating, it shouldn't be charged any higher than at 20A.

Some guys will tell you not to charge a battery faster than 10% of its AH rating (reserve capacity rating again). That's a more conservative number than the method above.

That being said, I still only charge mine at 5A. It gets the job done in time for the next fishing trip, and is cheaper than a faster charger.

[jooleyen]

Thanks all. Here is what I learned...

An Optima battery is an AGM battery, not a "gel" battery or regular flooded acid battery. A deeply discharged Optima battery (less than 10.5V) will not test or recharge properly if treated as a regular flooded battery or gel battery. A handheld electronic battery tester will most likely provide inaccurate test results.

An Optima battery has the benefit of very low internal resistance, which allows high amperage output as well as efficient charge acceptance. This benefit also allows an Optima battery to run longer than its specified ratings and run to a lower voltage than typical flooded batteries. All of this can lead to confusion when it comes to recharging a deeply discharged Optima. Most basic battery chargers have a built-in function to prevent charging a battery with less than 10.5 volts. If your Optima is discharged beyond that, the battery charger may not start up.

Most high-quality, modern battery chargers now have built-in features to charge AGM batteries like Optima. Some have specific AGM settings which should be used to charge an Optima. Do not use “gel” or “gel/AGM” settings, as they will not fully charge an Optima and could damage it over time. However, even some AGM compatible chargers will not recharge deeply discharged (less than 10.5 volts) Optima batteries. It may be necessary to follow the instructions for deeply discharged batteries.

For regular charging we recommend max 10 amps, 13.8-15.0V. For float charging we recommend 1 amp max, 13.2-13.8v.

Under normal (engine starting) conditions, an Optima battery should never experience “at rest” voltages below 10.5 volts. In these applications, most 12 volt chargers (old or newer) or alternators will sufficiently recharge an Optima with at least 10.5 volts.

Typically we only see issues with charging when it relates to standalone deep cycling applications or severely discharged Optimas. The chargers below generally will charge a deeply discharged Optima battery.

Here are a few chargers/maintainers that we have tried and like:

Ctek, Multi US 7000 or 7002:
http://www.ctek.com/EN-US/Buy-US-Charger.aspx
ACI, 7 amp version 1214CC
http://www.acichargers.com/product_specs.htm
Interacter, EX 12 volt model:
http://www.interacter.com/EX_Page.htm