iMAX B6 80 W / 6 A: What This RC Charger Can Do and What to Check on Clones

The iMAX B6 80 W / 6 A is an RC charger designed to balance-charge multi-cell lithium batteries. The listed version includes an external power adapter and supports LiPo, Li-ion, LiFe, LiHV, NiMH, NiCd and Pb batteries.

The iMAX B6 name, however, is used for both original SkyRC products and many clones. Their specifications, calibration and safety features may differ. Check the supported programs, power requirements and voltage readings of your particular unit.

Why balance mode matters

With a multi-cell LiPo battery, monitoring the total voltage alone is not enough. For example, the individual cells in a 3S pack can have different voltages even when the total looks normal. Without monitoring each cell, one could reach an excessive voltage before the others.

Balance mode monitors the cells through the JST-XH balance connector and tries to equalise their voltages. For balance charging, connect both the main power lead and the balance connector: the former carries the charging current, while the latter allows the charger to monitor individual cells.

The B6 design supports lithium packs up to 6S. Before connecting a pack, check the capabilities of your particular version and the correct connections in its manual.

What the 80 W and 6 A limits mean

The charger is limited by both maximum current and maximum power. At a lower voltage, it may reach 6 A; at a higher voltage, the 80 W power limit will restrict the current first.

For a 6S LiPo at 25.2 V, the theoretical limit is:

80 W / 25.2 V ≈ 3.17 A

At that voltage, the charger cannot supply 6 A. The actual current may be lower because of losses or limitations in the power supply. In addition, current gradually falls during the final constant-voltage, or CV, phase. The 6 A figure therefore does not tell you the current throughout the entire charge cycle.

The external adapter matters too

The listed version comes with an external adapter. Different B6 packages use power supplies of approximately 12–15 V, depending on the version. Before connecting one, check the required input voltage and specifications of both the charger and the adapter.

If the adapter cannot supply enough input power, the charger will not reach its full 80 W output. Assess the whole setup rather than just the figure on the charger: the power supply and energy-conversion losses both matter.

Choose the right program for each chemistry

LiPo, Li-ion, LiFe and LiHV batteries require different charging parameters, including end voltage. Selecting a “similar” program is not enough. Choose the battery type and cell count shown on the battery label, and before starting, check that they match the settings and information on the display. If they do not match, do not start charging.

Supported chemistries can vary between versions and clones. If your unit does not offer the correct program, do not charge the battery using another mode.

NiMH and NiCd batteries use a different charge-termination method from lithium cells. The charger monitors delta peak and other parameters, so selecting the correct chemistry matters here too.

The Pb program is intended for lead-acid batteries. It may be useful for smaller batteries, but the 80 W and 6 A limits do not automatically make it an ideal charger for a large car battery.

Storage and fast charge

Storage mode brings a LiPo to approximately the level suitable for storage. It is useful when you do not plan to use the pack soon and do not want to leave it fully charged for a long period.

Fast charge shortens the final CV phase. Charging may finish sooner, but the battery may not be charged as fully as it would be with a normal balance charge. For regular use of a multi-cell LiPo, balance mode is the more conservative choice.

What charging current should you set?

A rate of 1C corresponds to a current numerically equal to the battery's capacity in amp-hours:

• For 5000 mAh, 1C is 5 A.
• For 2200 mAh, 1C is 2.2 A.

That does not mean 1C is safe for every pack. Follow the battery manufacturer's instructions and maximum charging current; the permitted value may be lower. A higher current can shorten charging time, but it can also put more strain on the battery.

Clones and checking voltage readings

Clones can differ in build quality, calibration, safety features and achievable power. Before regular use, it is sensible to compare the cell voltages displayed by the charger with readings from a quality multimeter. Make the check before the battery is fully charged rather than waiting until the end of the cycle.

• Record the individual cell voltages displayed by the charger.
• Stop charging and disconnect the battery.
• Using a correctly configured multimeter, measure each cell through the balance connector and compare the readings with those you recorded.

Only do this if you know how to use a multimeter safely and understand the connector's pinout. Do not short adjacent contacts with the probes; if you are unsure, ask an experienced professional to perform the check. Small differences can also result from meter accuracy and the time between readings.

For example, if the charger shows 4.20 V and a verified measurement of the cell is 4.26 V, do not use the charger until the cause has been resolved. With LiPo batteries, even differences of a few tens of millivolts matter.

LiPo charging safety

Charge LiPo batteries under supervision, in a suitable non-flammable location and according to the battery and charger manufacturers' instructions. Before starting, check the chemistry, cell count, current and both cable connections. Stop charging if you notice unusual heating or another problem.

Do not attempt to rescue a swollen or mechanically damaged LiPo by charging it.

Who is the iMAX B6 suitable for?

The B6 is a versatile option for RC users who need to handle different battery types and use balance or storage mode with multi-cell lithium packs. Its 80 W output limits charging current, particularly at higher voltages, and the suitability of a particular unit also depends on its adapter and build quality.

Before buying or using one regularly, check the functions of that version and, after purchase, check its voltage readings. For LiPo batteries, accuracy matters more than an “80 W” label on the box.