super small car battery

[Muzza_NZ]

hi everyone.
we're putting a new battery in the project RX7 and came across a small sealed battery that this crowd are selling for street applications:

http://www.batterydirect.co.nz/vertex_drycell_battery.htm

Another company selling the same thing rebranded:
http://www.performancedistributors.com/batteries.htm

They were reasonably priced and only weigh ~5kg so Chris got one sent to us. The battery specs were surprisingly similar to those of my 'cheap and nasty' jump starter so I pulled it to bits, and wouldn't you know, the batteries were dimensionally identical; name plate data was pretty close too. (see attached pics)

The vertex battery was tested at ~400A cranking, but the maximum charge current @~14V is ~5A, so a few repeated starts on a cold engine will pretty much flatten it, and take 10-30min of driving to recharge (pretty hard on the battery if you ask me)

Time will tell whether it was a wise purchase or not, it appears to start the car ok, and I'm guessing that if I have a maintenance charger on it when it's in the shed it will last a while.

Interestingly, notice the elcheapo battery has 'do not recharge' written on it, and under the vertex label you can see toyoma or something simliar.

Anyway, the point of my long winded ramble was to ask you knowledgable chaps what you reckon about using it...

 

[sideshow]

what is car being used for
small and dry cell batteries can not always but can cause headaches

odyssey batts if half flat are very hard to charge up by driving car

i dont usually use them for every day cars

and even race cars if they go flat afew times u throw them out

for the sake of afew kgs u cant o past a normal 13 plate

but each to their own

dry or small batteries are bloody good except when they break down

 

[cribbj]

I ran an Odyssey SLA type battery in my Supra for a few years, and it was good, except it had no cranking reserve. If the car didn't start in the first 5-10 seconds, that was it. No more juice.

I wouldn't use one of these in a cold climate, or with a hard to start car, and I would definitely keep a trickle charger on it whenever the car is in the garage.

 

[Muzza_NZ]

Thanks Jim and John,
the car will be used pretty infrequently so a trickle charger will be on it whenever it's in the garage. It will be a combination track/road car.

The 1UZ will be completely standard for 6 months or so and the climate here in NZ is relatively warm by global standards, so am picking that we'll be ok for a while.

The seller does suggest that if we're doing work or repeated starts on the car, that we replace the battery with a conventional full sized one. That makes complete sense with such a small reserve.

Cheers,

Muzz