AGM - Absorbed Gel Matt batteries are safer than SLA - Sealed Lead Acid. AGM batteries contain a thick gel liquid, SLA contain a thin watery type substance. GEL Cell batteries differ from AGM, GEL Cell contain a thick silica type gel cell that the electrolyte is suspended in. Gel Cell are more expensive than AGM and require careful maintenance and the correct charger must be used. AGM and GEL batteries are approved for use on aircraft but SLA batteries are not.
AGM batteries contain just enough thick liquid to allow the electrolytes to travel around the plates, they should not leak if the casing is broken. SLA will leak acid if the casing is broken. AGM are accepted by airlines as they are deemed safe for this type of travel.
The average life span of an AGM battery is 12 - 18 months if maintained properly. I have come across some batteries that are several years old and still working well so please remember the above is an average.
It can become very confusing choosing the correct battery with so many options out there. AGM batteries are reliable and seem to be the most popular choice at the moment. If you use your mobility aid daily then AGM are perfect for this, remember to charge them each time you use them. If storing your batteries for more than 2 weeks disconnect the batteries to prevent the batteries discharging. Check the batteries at least once a month and put them on charge when doing this. An AGM battery will hold its charge for up to 6 months but charge it before use. When charging always leave the charger on for a few hours after the LED light o the charger has gone green.
Sealed Lead Acid - SLA are still a good battery, if you use your scooter or Power Chair for occasional use say once or twice a week then this cheaper option is perfect for you. You will get up to 10% more range from SLA than AGM.
CAR BATTERIES ARE NOT DESIGNED TO BE USED FOR MOBILITY AIDS! Car batteries are designed to give a short high amp discharge to start the engine. 'Deep Cycle' batteries that are used for mobility aids are designed to give a steady output for a long period. NEVER USE A CAR OR MOTORCYCLE BATTERY CHARGER TO CHARGE YOUR MOBILITY AID BATTERIES! I have seen the consequences of this, the battery had been charged using the incorrect charger and had swollen so much that they had burst. The customer was trying to save money by not buying a new charger, they ended up having to buy new batteries and the battery box. By trying to save £30 they ended up paying over £200. If you are ever in need of help or advice please call me, nothing is ever a 'stupid question' it could save you a lot of money. I have seen many problems that the customer felt a little embarrased for calling me out when I point out the cause but they learnt something and all was well. There are many subjcts I struggle with and need help so it is better to ask than get it wrong.