"Volts mean nothing. Amps mean everything!" - Your Battery

isn't the best way with tech stream while driving?

 

Seems like people have been talking amp-hours since the earliest battery-reconditioning posts I ever saw around here.

 

Step one: there's ten thousand posts on this topic that you could catch up on........

 

The first question when testing for Ah is the load the testing should be. No point in the lead acid high load test, depending on the chemistry, NiMh in this case, the load current can be huge, enough to destroy the testing machine, so the load in amps over a given time will determine the C value, C is the capacity, the number after the C is the number of hrs this battery should be able to provide a current (amps) before dropping below a given voltage .....

This sort of testing is done at cell level generally, can't do that with a Prius module, because each module is made up of 6 cells, it only requires a single cell to be weak to condemn all 6 cells, so a high C value could destroy a cell that simply needs to be balance charged and most likely, all 6 cells need to be topped up, they refer to it as rehydrating on this forum, so try looking up that topic to get more information regarding that topic, along with forcing the pressure relief valve free so the electrolyte no longer leaks out of the terminal seals ......

To find the C value, you need the cells to be in their best condition first, so all those steps must be completed first, then we can talk about C values, the cell capacity is only 6 Ah in as new condition, so a C1 test would be possible with 6 cells in good condition, so, get that part sorted first ....

T1 Terry

 

The terminology is one of the first things to make sure you get right, and that helps everything else be less confusing.

'Cell' is the smallest unit. It's a standard term. One cell has an anode and a cathode and an electrolyte between them, and the chemistry of the anode and cathode and electrolyte determine its characteristic voltage. For one NiMH cell, that's 1.2 volts, nominal. (Doesn't depend on who built the cell or how big it is or what it looks like, but only on the chemistry.)

'Modules' are the smallest things you can take the Prius battery apart into. Each module is long and flat and contains six cells. So the voltage of one module is 7.2 volts, nominal.

'Blocks' are pairs of modules. Because the modules have terminals on both ends and are all wired in series, and all the ECU's voltage sense wires attach to the terminals along one side of the battery, each pair of those adjacent terminals will measure the combined voltage of two adjacent modules, otherwise known as one block. So the nominal voltage of a block is 14.4.