If the ECU does not receive full voltage, the injectors and spark plugs do not get full energy, and do not operate as intended. This can result in less fuel being injected, and misfires from the ignition system, as the ECUs on 99% of all motorcycles do not have a way to correct for lower voltage supply. In order to combat this problem, many riders install a low amperage battery maintainer. This is not a full battery charger, but simply a 0.8 - 2.0 amp trickle charger that just has enough supply to keep the battery charged when it is not ridden regularly – a "tender" if you will. In colder weather, the chemical reaction in the battery slows down, and the battery voltage and amperage output is reduced. Many of these low amperage "tenders" cannot offset this reduced chemical output, and as a result, the battery is not fully maintained. This results in lower voltage and reduced cranking and reserve capacity.

On racing bikes where power and consistency demand great loads on the battery (especially at peak torque and high rpm, or with nitrous oxide and turbochargers) system voltage and reserves are extremely important. This is even more important when running reduced output charging systems or for total loss (no charging system). The wrong battery selection can mean you are NOT the first to cross the finish line. Here weight and capacity are always competing priorities – especially for total loss systems.

Batteries are rated by the reserve capacity in amps per hour, as well as cold cranking amperage (CCA).

Most stock batteries are selected by the motorcycle manufacturers based on a wide range of requirements. The most important of these is cost, space, and the minimum requirement to start the engine. For performance use, we really need to add a few more requirements – additional cranking amperage, additional amp/hour reserve power, and light weight.

Battery technology over the past decade has improved by leaps and bounds. The common lead-acid battery over past 100 years, has been recently improved by sealed gel cells, absorbed fiberglass mat (AGM) cells, and over the past few years by lithium polymer (LiPO) technology. LiPO battery cells offer a quicker release of energy than older technology cells, and this can result in faster starting speeds, as well as better output to injectors and coils under the most demanding conditions. The most recent advances in LiPO battery technology is lithium ferrous polymer (LiFePO) designs that reduce size and weight drastically, while releasing energy much more rapidly than possible with older battery technologies. This new battery technology has been expensive... with 4 – 12 amp/hour 12 volt batteries costing $250-$500 or more. This cost has mostly kept this technology on the race track, and off the street, out of the hands of the budget limited enthusiasts.

Shorai Batteries have changed the battery industry. Their LiFePO batteries for motorcycles come in two case sizes that are both smaller and drastically lighter than the stock battery they replace, but most importantly this comes at a price that is only slightly more than what most dealerships charge for a replacement battery. By selecting the smaller case size, even the bikes that come from the factory with very limited battery room, and amp/hour reserves, can replace their stock 7 or 9 amp/hr battery with a 14 amp/hr unit, and still reduce size and weight. This gives the motorcycle better starting in all conditions, and most importantly, more reserve output to ensure that the ECU is getting the power it needs for performance. And the weight loss that is located high on the bike means that the bike will now be more agile, nimble, and quicker in the twisties or on the track.

For reference use, below you will find a list of common lead-acid and AGM battery sizes and weights compared to a similar Shorai battery. These weights are taken from manufacturers' sites.

YTZ7S                 5         LFX07A2-BS12     1.06

YTZ10S               7         LFX09A2-BS12     1.27

YTZ12S               9         LFX12A1-BS12     1.35

YTZ14S               9         LFX14A1-BS12     1.68

YTX14AHLBS     8        LFX14A2-BS12     1.68

YTX18-BS         11.4     LFX18A1-BS12     2.19

From the above, you should be able to see that the compact size and weight of the Shorai batteries allows for an increase in output and reserve capacity, and still greatly reducing the battery weight in even the most cramped street and track bikes. On our personal and shop bikes, we have stepped up the output and reduced weight by using Shorai batteries. We have even gone as far as replacing the expensive LiFePO batteries in our racing and track bikes with Shorai units due to the reliability, ease of maintenance, and warranty, with a big reduction in cost.

Selecting a replacement Shorai battery is not as hard as it would first seem.

Look at the Shorai part numbers. For part number LFX14A2-BS12 the LFX is just a prefic for the LiFePO technology. The 14 is the amp/hour reserve time. The A in a normal terminal design [an L means the terminal polarity (+ or -) is reversed]. The 2 means a smaller case size. And the -BS12 means that it is a 12 volt battery. Part number LFX18L1-BS6 is a 18 amp hour reserve, large case, reverse terminal, 6 volt battery.

Simply look at the battery you are currently using to see its size and which side the terminal posts are on. What we suggest is to compare this with the small case Shorai cells (A2 or L2 in the part number) with as much amp/hour reserve as you can. Then make sure the terminals are on the correct side (A or L post design).

Or better yet, simply use the battery application selection for your make, model, and year at www.shoraipower.com then contact us for the best pricing possible. We will meet or beat anyone's advertized price on Shorai batteries, and we are very competitive on shipping prices to get you the best rate possible, just give us a call at 205.663.4304.

The reason we suggest the small case size is that until you need an 18 amp/hr battery, there is no benefit to the larger case batteries in output or weight. Comparing the lowest Shorai amp/hr (the 9 a/h cells) to the highest reserve in the small case size (the 14 a/h cells) only adds .62 pounds, but gives 210 cold cranking amps compared to 102 CCA for the 9 a/h cells. To us, the choice is simple. But if you want a lower a/h or CCA rating in the small or large case size, the choice is yours, and these are a bit less expensive if you are on a tight budget.