Optima Yellow Top D35 Battery Review

This moderately priced and fully capable dual purpose battery is well-suited for a wide range of boaters looking for a single battery to handle their engine cranking and deep cycling needs.  It is light and durable, but it still provides enough electrical power to satisfy all but the high end of energy demand.


This product has a solid CA (cranking amps) of 770, more than twice what is needed to start a normal, mid-size boat or automobile engine. Its CCA, the ability to generate power at zero degrees Fahrenheit, is 620, so this is a product that can deliver in extreme weather conditions.

As its reserve capacity, the time the D35 battery can produce a 25 amp current without recharging, is 98 minutes, this product will work well with all but the very largest trolling motors.  The Optima D35 Yellow Top’s Ah (a measure of overall energy storage capacity) is 48, which places it in the mid-range of dual purpose batteries.

This battery is also designed to last.  Optima offers a warranty of three years, but customer feedback indicates that they get as many as eight years out of it.  According to the manufacturer, the battery can be fully discharged and recharged 300 times.

This is an AGM battery with the special Optima feature of Spiral Cell technology. The AGM technology involves using glass layers between the coated lead plates of the battery to absorb acid in a way that maximizes energy and minimizes leakage and the potential for corrosion.   Optima has added a new twist in substituting the normal flat lead plates with a spiral design that makes the battery more efficient and more resistant to temperature changes and to damage from vibration.  It also makes these batteries significantly lighter.

Because of the AGM technology, this battery can be mounted in any position and its design prevents the acid solution from spilling and causing the corrosion that can leave you stranded on the water.  The thick and durable plastic exterior also contributes to the ruggedness of this battery.  I offer one word of warning here about mounting this battery.  It comes with a cover which also serves as the height adjustment / tray stand so that you can mount it securely.  Do not discard this cover as you unpack the battery or it might cripple your attempts to properly fit the battery in place.

An advantage you get from an AGM battery like this one is that they charge about five times faster than the wet cell or gel cell batteries, and they are more reliable in providing electric current.  You need to be careful with charging them, though.  If you attempt to use a charger designed for non-AGM batteries, you are likely to experience failure and frustration.

For a 12 volt battery of group size BCI 35 (9 and 5/16” x 6 and 13/16”x 7 and 5/8”), this Yellow Top is comparatively light.   At 36.4 lbs, this battery, like Optima batteries in general, run about 15 to 20 lbs. lighter than other 12 volt batteries.   This has made it a favorite of stock car drivers, but even skippers of small crafts or anyone who has had to lug these lead-filled boxes from boat to parking lot.


Weight:                36.4 Lbs.

C20 Capacity:     48 Ah

Post Type:           SAE Post

CCA:                   620 amps

Width:                 6.75 inches

Length:                9.38 inches

Height:                7.69 inches

RC:                    @25 amps:  98 minutes

Voltage:               12 volts

Group Size:         BCI 35

Int. resistance:  .0003

CA:                    770 amps

Advantages and Limitations

The light weight makes the optima yellow top d35 battery portable.  As it less than 10” by 7” and light, you can mount it in smaller crafts that do not have the space for mounting bulkier batteries.

The reserve capacity makes this battery very good for almost all trolling motors.

If you are dealing with large outboards and large trolling motors while running multiple accessories, you might need to go up to a higher capacity.

You do have to be careful charging these batteries.  They can be damaged if you overcharge them.  They will be undercharged if you do not use the proper AGM-friendly chargers.  You should not let them run down all the way or that also can damage the battery.  If you take care of them well, though, they have many advantages.


The Optima Yellow Top D35 battery will serve the needs of the average boater well.    If you are looking for a battery to crank a mid-size outboard, and power a normal trolling motor while using sonar devices, this one is absolutely fine.  If your electrical needs place you on the high end of the spectrum, you might need to pay more and get more Ah.