Technical FAQs

Please find below some of our frequently asked technical questions.
If you can't find the answer you need or wish to discuss our customisation capabilities please contact our technical team:
01189 795319

What is the capacity of my battery?
The unit used to describe battery capacity is an Ampere-hour (Ah). This is a measure of how long a continuous current can be supplied before completely draining the battery of useful energy. There should be an indication on the battery that gives an Ah value. The most common discharge rates are 20h, 8h and 1h.
Example: A 20Ah battery can supply 1A for 20h.

What is energy density?
It is the amount of energy than can be stored in a volume or mass. Therefore, there are two ways to write this.
Volumetric energy density is how much energy can be stored in a volume. The units are Watt-hours per litre (Wh/l).
Gravimetric energy density is the amount of energy that can be stored per unit mass. The units are Watt-hours per kilogram (Wh/kg).

How long does it take to charge a battery?
If the charging current (I) and the capacity of the battery (C) in Ah are known, then you can estimate the charging time using the following formula:


1.2 is a factor that adds 20% extra time to ensure the charge cycle is fully complete.

Will any charger work with any battery?
No, each battery chemistry and each capacity battery will require a different charger. This is due to the detection methods varying amongst them. Using a battery charger designed for a 10Ah lead acid battery will not be suitable for a 10Ah in any other chemistry.
Carefully check the chemistry of your battery when selecting a charger.

How can I find the manufacturing date of my product?

On each product there is a label that indicates the year and week of manufacture.

How do I select an appropriate power supply?

A power supply will deliver a fixed voltage up to a maximum current and delivers only the current required by the device. A device requiring 0.8A will function perfectly using a 1A power supply if the voltage is correct.

If you're unsure please contact our technical support team:

01189 795319
08:00-17:30, Monday – Friday

Should I fully discharge my battery before charging it?

This depends on the chemistry of the battery. A lead acid battery in ideal conditions should not be drained further than 50% in order to prevent sulphating. Other chemistries including Lithium-ion, Nickel metal hydride and LiFePO4 can be used until very low percentages and recharged with no issue. Nickel-cadmium batteries are prone to memory effects meaning they should be drained fully occasionally to ‘reset’ their capacity memory.

How should I store my battery?

If you are storing a lead-acid battery it should be stored with as much charge as possible at ~20˚C and will last between 6 months and 2 years depending on the quality of the battery. Other chemistries including NiCd, NiMH, Li-ion, LiFePO4 should be stored in cool dry places with approx. 40% charge. In this state NiCd can last between 1.5 to 3 years, NiMH last approx. 3 - 5 years while Li-ion, LiFePO4 can last up to 2 - 5 years. Storage under ideal conditions can double these estimates. The timeframes above are drawn from experience in household conditions. Shelf life will depend on the quality of individual products – consult the manufacturer guidelines for more specific information about your product.

Is Pulsar Developments able to fit output cable connectors?

Yes, Pulsar Developments has an experienced team of engineers that can replace a wide range of output connectors. All you need to do is provide a connector type/spec (preferably with a product code) and a polarity requirement and we can fit it for you.
Please contact our technical support team:

01189 795319
08:00-17:30 Monday – Friday

Can Pulsar Developments provide batteries for my charger?

Pulsar Developments can source and supply a wide range of lead acid, NiMH, and Li-ion batteries or cell packs. Please contact Pulsar Developments directly for more information on custom made battery packs.

Is Pulsar Developments able to provide a power supply/charger to meet my exact requirements?

Yes, we have support from Mascot’s experienced design team and can either configure standard products or find a non-standard solution by generating a custom design.
Please contact our technical support team:
01189 795319
08:00-17:30 Monday – Friday

Can Pulsar Developments program nickel metal hydride chargers to suit my cell being used?

Yes, there are multiple parameters that can be adjusted to meet your needs. The settings that can be programmed by Pulsar Developments include negative voltage drop (-dV), temperature gradient (dT/dt), safety timer, start timer and top off charge timer.

Does temperature affect the performance of batteries?

Yes, as batteries rely on chemical reactions.

Cold - the colder they are the slower these reactions are reducing electrical performance.

Hot - The hotter a battery is, the more energy is lost to the surroundings. This is due to faster reactions occurring increasing the self-discharge rate of the battery – lowering the effective capacity of the battery.

Each battery manufacturer will provide an operating temperature range for the best performance.


Are there any potential dangers when carrying loose batteries?

Yes, care must be taken to safely handle batteries to prevent the terminals short-circuiting. Any metal or conductive material such as coins in pockets can link the anode and the cathode together and damage the battery and those nearby.

Can NiCd batteries be replaced with NiMH batteries?

While they are similar it is not recommended to do this exchange. Chargers for NiMH need to be much more sensitive to correctly detect the end of charge and so a NiCd charger cannot be used on NiMH. However, a NiMH charger could be used to charge NiCd batteries.

Can NiCd/NiMH and Lead Acid batteries be replaced by rechargeable Lithium-ion/Polymer batteries?

No, Li-ion batteries are much more energy dense than other chemistries and work at different voltages. Usually entire systems and chargers are designed specifically for lithium-ion batteries and using them in a setting without these design considerations can lead to damaged devices and could pose health concerns to those nearby.

Can battery brands, ages and chemistries be mixed to power a device?

No, as each battery chemistry and capacity require a unique charging solution. Charging with the wrong charger will cause damage to the batteries. Batteries of the same chemistry at different ages will have varying capacities and so can give false charging signals – potentially damaging the batteries and device via overcharging.

Batteries in a device should always be of the same chemistry at the same voltage, capacity and of the same age.


What does IP rating represent?

IP (ingress protection) classifies and rates the level of protection of mechanical casings and electrical enclosures against intrusion, dust, accidental contact, and water. The first digit gives the level of intrusion protection and the second digit gives the amount of moisture protection. Higher numbers/digits indicate greater protection.

On a Mascot NiMH battery charger where dT/dt is used, which is the best thermistor to use?

Pulsar developments have prepared a technical document that you can review to learn more information about this here.

What is an alternative item?

An exact alternative is functionally identical (same form, fit and function) but has a different unit of measure from the same manufacturer. An upgrade alternative is a product that has been improved by the same manufacturer. A suggested alternative is a product that is functionally similar with similar form and fit.