UK Replacement Battery

[Barry]

I mentioned recently that I was ordering a new battery to replace my 12 year old Varta wet cell.

They sent the wrong one !

It should have been an AGM sealed battery with standard lug terminals.

Instead it's a a Gel AGM sealed battery with M5 vertical threaded terminals.

The good news is it fits nicely being almost identical in size to the stock Varta perhaps 1 or 2 mm narrower and lower which means it went in a little easier.  It's definitely easier to make the connections from above with the supplied stainless steel bolts and washers so I've decided I like the terminals.

Gel AGM vs AGM had me puzzled for a while. They are both sealed maintenance free batteries although not exactly the same. AGM batteries use liquid electrolyte similar to a wet cell the difference being it is absorbed into glass mats in contact with the plates.

Gel batteries have the electrolyte in a thickened gel form but no glass mats.
 
Gel AGM seems to be a new type that combines the advantages of both. Gel can last a little  longer and deep cycle better but have lower cranking amps. Combining gel with glass mats has improved that if not to the same level as an AGM. This battery is quoted as having a maximum current of 300 Amps although the temperature isn't specified. It works anyway with a cranking voltage of 11.2 volts which seems very respectable.

I'll report back in 12 years if it last as long as the VARTA which incidentally was still starting on the button. The self discharge rate had just got high enough to be tiresome and needed charging at least once a week. The new battery is supposed to lose only 3 % a month so with regular use I might not have to charge it at all.

[clonmore1]

Hmm, 12 years seems a little long for a test report Barrry, I may need an earlier result before I purchase mine!

[Barry]

Hmm, 12 years seems a little long for a test report Barrry, I may need an earlier result before I purchase mine!  

We'll see. I don't really expect it to last that long.  This is a very inexpensive battery at £33.99 delivered. I couldn't buy the cheapest wet cell for that. My guess is they are a generic made in China type that may even be the same as the ones available in the US and other parts of the world under a different brand name. In other words badge engineering. Although many are using them in bikes they are a general purpose battery not specifically designed as a starter battery.

All I can say so far is it spins the engine very smartly and the rested voltage is much higher than a wet cell. I measured 13.12 volts after charging and an overnight rest. I may have to tweak the voltage regulator up a little. The battery is no lightweight at 12lbs but the old stock Varta was exactly the same weight on the scales so I'm no worse off.

One disclaimer if anyone is thinking of purchasing this type of battery. Compared to a wet cell AGM's and Gel cells are not very tolerant of being overcharged as they can't gas off like a wet cell so you need an automatic or voltage limited battery charger to look after them. I've got an automatic charger with an internal adjustable pot which I've set to suit at 14.5 volts full charge and 13.8 volts float.