Leisure battery size

we have just had a new leisure battery of 90AH fitted when the old one was 110AH ( we asked for the same size)  Will this make very much difference in the length of time we can run our lights?

Hi there,

The percentile length of time will be 90 divided by 110 multiplied by 100 = 82% of previous battery amps available. i.e. a loss of 18%.

We manage quite well with as ordinary 70Ah lead-acid battery without any problems even in winter running the heater, TV and lights.  

Hope this helps. 

Best regards,

I agree with Dutto that you have lost out but it would be worth checking the C5 & C20 values of the old and new batteries before getting into a discussion.
It's possible, but unlikly, you find that the C5 value on the new battery is higher than on the old battery and this would potentially give you more time on battery power, assuming a constant load of 5A.

Regards

Charles

What is C5 and C20? Presume it is to do with AH vs discharge rates?

Hi Jaytee

Correct, they are industry standards discharge/time rates.

Yes, I did notice that when looking at batteries a while ago. One was brilliant 115 AH but only at a 115 hr rate, when at a sensible 5 or 10 amps if was quite poor.

Jaytee wrote:Yes, I did notice that when looking at batteries a while ago. One was brilliant 115 AH but only at a 115 hr rate, when at a sensible 5 or 10 amps if was quite poor.

Hi there,

That's why the old term for them was/is "Traction Battery".

The ordinary lead-acid batteries are designed to give a massive amount of amps for the purpose of starting an engine (i.e. to power the starter motor) whereas the standard "Leisure Battery" is designed to give a steady outflow of amps and in many cases just wouldn't deliver sufficient amps to start an engine.

For us, we manage quite well with an ordinary 70Ah traction battery for three reasons ....

1.  It is generally much cheaper than a Leisure Battery.

2.  It is there as a standby if we need it to start the engine.  (That's why we carry the jump-leads.)

3.  Even in the wintertime it delivers adequate amps for heater fan, lights and TV for at least 24 hours without EHU or solar input.

To prevent the possibility of damage we monitor the voltage and ensure that it is kept at or above 10.4V.  This hasn't been a problem and the one we have fitted at the moment (a 70Ah Bosch bought from Halfords) has been in place for just over four years and is still working very well.

Hope this helps. 

Best regards,