Xantrex Technology 10 owner manual Parallel

Operation

Parallel

Connecting two batteries in parallel will double the amp hour rating of the battery bank, while the voltage will be the same as each individual battery. For example, two 12 volt 105 amp-hour batteries in parallel will produce one 12-volt, 210 amp-hour battery bank.

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Figure 3-6Parallel Battery Connection

Only similar batteries should be connected together in one bank. Do not connect old and new batteries or wet and gel cell batteries together. In the above drawing, note that the load is connected to the positive terminal of the first battery and the negative terminal of the last battery. This practice helps to balance the battery bank.

Important: Always use proper terminals for your interconnecting battery cables and cable which is 2 AWG or larger.

Battery Bank Ratings and Sizing

Deep-cycle batteries are usually rated in amp hours. The amp-hour rating is based on a 20-hour discharge cycle; therefore, a 100 amp-hour battery can deliver 5 amps for 20 hours. If the discharge rate is greater than 5 amps, the available amp hours are decreased. If the load is increased to 100 amps, only about 45 amp hours will be available.

Another common rating is reserve capacity expressed in minutes. This is derived by placing a 25 amp load on the battery and measuring the time until the battery voltage reaches 10.5 volts.

Deep-cycle batteries can be discharged about 80% before permanent damage occurs, though shallower cycling will result in much longer battery life. Fifty per cent cycling is generally considered to be a good compromise between long battery life and a reasonably sized battery bank.

To achieve 50% cycling, you should calculate your amp-hour consumption between charging cycles and use a battery bank with twice that capacity.**

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