Batteries

[classic1952]

My recently bought 2005 SV with the 1800 k-series is currently fitted with a Powervamp Racing 25aH battery. My only concern is that the first turn of the engine is always very slow, even on a fresh charge, but once it is spinning it starts OK. I just wondered if this battery is really powerful enough for an 1800 engine? If not, should I revert to the usual Banner 30aH battery or a larger gel battery?

[Jonathan Kay]

Which model of Powervamp?

What's the battery voltage at rest, minimum during cranking and at 3,000 rpm?

I'd recommend checking all of the relevant cables and connections, including earths.

That "Ah" value measures the energy stored in the battery, not the peak current it can deliver during starting. That's described by various measures of which "CCA" is probably the most common.

Jonathan

PS: Today's summary of batteries for Sevens!

[classic1952]

Thanks. The only info shown on the battery is as above, but I will look up the spec and do a voltage test on it. I am leaning towards a Banner battery as they were trouble free on my previous Caterham.

[Jonathan Kay]

If you measure the external dimensions we can probably work out what you've got.

There's general satisfaction with the PC680 and that's what I have on my 1800 K. It's unlikely that you've got anything smaller but it's possible, 

I wouldn't use an unsealed battery.

Jonathan

[classic1952]

Thanks. I will do that in the morning. I suspect you are right about the model.

[anthonym]

I wouldn't use an unsealed battery.

Why?

 

[classic1952]

The model is definitely Powervamp Racing 25, leading me to think it is a few years old. The 20 hour aH is given as 18, whilst the cranking torque is 680, way below the batteries in the Odyssey spec sheet. The batter measures 180mm long by 170mm high by 80mm thick, which does not tally with any of the currently listed batteries. The latter figure might explain the slow initial cranking, which speeds up once the engine is turning. I think in all probability the battery is marginal for an 1800cc engine.