What is the difference between a Ni-Cd and Ni-MH chemistry battery?
The main difference between the two is the fact that Ni-MH batteries (the newer of the two technologies) offer higher energy densities than Ni-Cd's. In other words, pound for pound, Ni-MH delivers approximately twice the capacity of its Ni-Cd counterpart. What this translates into is increased run-time from the battery with no additional bulk to weigh down your portable device. Ni-MH also offers another major advantage: Ni-Cd batteries tend to suffer from what is called the "memory effect". Ni-MH batteries are less prone to develop this dreaded affliction and thus require less maintenance and care. Ni-MH batteries are also more environmentally friendly than their Ni-Cd counterparts since they do not contain heavy metals (which present serious landfill problems).
What is a Sealed Maintenance Free Battery?
Sealed batteries are known as maintenance free batteries. They are made with vents that (usually) cannot be removed. A standard auto or marine maintenance free battery is sealed, but not fully leak proof. Sealed batteries are not totally sealed since all batteries must allow gas to vent during charging. There are sealed lead acid (SLA) batteries that are non-spill able. Please read information on our SLA batteries, see AGM and Gel batteries below.
What is a WATT-HOUR (Watt-Hr, WH)?
A WATT-HOUR is the unit of measure for electrical energy expressed as Watts x Hours.
Can I take a wheelchair, scooter or other equipment that is powered by a sealed AGM or Gel battery on a airplane or cruise ship?
Yes. There should be no problem, the battery is considered non-spill able, non-hazardous, since it is a absorbed glass mat design. These sealed lead acid valve regulated (VRLA) batteries are classified as "Battery, wet non-spill able, not subject to regulations" by DOT and IMO. By IATA they are classified as "Not restricted for air transport" and they are in compliance with IATA/ICAO special provision A67. For the gelled electrolyte batteries, they are classified as "Battery, wet, filled with acid, UN2794, Class 8". They can be legally shipped via air with special packaging etc.
