Battery testers
QI have seen recently a few mentions of 12-volt car battery analysers. Gendan offer the Foxwell BT100 at £45 but they tell me it is not suitable for testing EFB batteries which I require. My second car has an AGM battery, so they recommended the Foxwell BT715 at £115 which can test both types. This price is more than I can justify for the limited times I would use such a device. Are you aware of any other reliable battery analyser that tests both types of battery for a more reasonable price?
Melvyn Allen
A
The EFB (Enhanced Flooded Battery) is built to accept increased dynamic charge current and can receive charge at a higher rate (around 170%) than the standard 12V battery. This is due to its improved design and the addition of special carbon additives, along with the high-charge acceptance envelope type separators it contains.
As the high-rate discharge tester is not an option on modern batteries and not one I would recommend on any battery now – and as the use of a battery hydrometer is not often possible due to the battery being sealed – this means the best method of testing the 12V battery is to use a modern tester.
Modern battery testers use a test algorithm to work out the state of the battery along with the capacity and the CCA of the battery. Due to the manufacture of the EFB battery, the algorithm needs to be highly-advanced and whilst the Foxwell BT100 would give a result, the result would be incorrect.
Unfortunately, the Foxwell BT715 is the lowest-priced tester I can find on the market to test the EFB and AGM batteries.
You may also be interested to hear that a recent study indicated that around 90% of small workshops do not have EFB testing capabilities and are using older style testers which do not cover the newer battery format. The average price of the testers which do cover all the battery configurations is around £250.