was running a power vamp 25 but it failed last night !
coozer - 15/4/15 at 08:58 AM
It failed? What happened?
Was it spectacular?
CosKev3 - 15/4/15 at 09:03 AM
Yeah.a lot of people moan about the extra weight of a car battery though!
Fatgadget - 15/4/15 at 09:34 AM
quote:Originally posted by greavesy7
Can you run any type of car battery on a BEC ??
was running a power vamp 25 but it failed last night !
Supercapacitors!..check this out
coozer - 15/4/15 at 09:43 AM
Hmm, I looked into the capacitor route.. But, where can we buy super capacitors cheap enough in this country???
The yanks get them cheap bit here???
britishtrident - 15/4/15 at 10:14 AM
As rough guide batteries for engines 1000 to 1300cc need to be rated at 280 cca minimimum most small car batteries are rated about 340cca
The Amp Hours capacity rating depends on the pattern of your your useage but Caterham use 30AH, you probably won't find many car batteries
with a smaller capacity.
Hi,
When I first got the BEC I had no end of trouble with the battery. Was a nightmare. Went through 2/3 bike batteries. (Yes charge rate was all ok and
car behaved ok)
If I didn't get it started on the first time would not really start.
Got a battery off eBay for about 45 pound think they do one with a charger for 70 ish
Never missed a beet now.
The battery was a powervamp.
They are lot lighter than car battery and similar size to bike battery
britishtrident - 15/4/15 at 05:00 PM
CCA is a rather odd measurement because it is based on the amps a battery can supply at a specified low temperature for a specified time before the
voltage drops below a specified cut off voltage.
Par for the course the North American SAE, European DIN and Japanese measurement methods are totally different.
I have always used a traditional high current load tester for battery testing but I am increasing wary of using them especially on modern sealed
batteries.
As the big Varta tintop battery was given a hard time over the winter, flattened to 10.2v having been drained by parasitic current due six weeks
without being used or charged I decided to join the 21st century and blow £50 on a Ring RB50 digital battery analyser.
I am really very pleased with it it provides an percentage estimation of the charge capacity of the battery relative to a new pristine battery and an
estimate of the remaining CCA.
It has given me reassurance I can fly off to Italy without coming back to a flat battery.
Answer of - yes, small car battery no problem. People get the idea that too large a battery overwhelms the bike-style regulator, but it is not true*.
I ran a 38AH VW Polo-size battery on an R1 for a year or so with no issues (quite the opposite - *instant* start) and it lives on in the garage as the
jump pack.
I only tried this because my R1 (5PW) burnt a stator, as they do, and I bought the smallest car batt available nearby to get home running total loss -
no probs, despite 2hrs+ home! I then replaced the stator, left the battery - no problem. Got paranoid about the weight so the last 18months have run
the recommended Yuasa r1 replacement without any issues. But I also now have a small LED voltmeter on the dash (under a fiver from amazon) that comes
on with the battery isolator switch, and it is invaluable - if only to know for sure that running the fan and the headlights at idle causes no problem
*Bike regs are shunt regulators, that is, when the alternator's rectified DC output runs too high, they selectively short-out the stator windings
to clamp the output voltage - sounds brutal but it is pretty efficient, actually (near-0v winding output * however large current = very small loss).
This system is totally blind to load support on the output side - has no problem at all supplying a battery as large as you like, or a huge draw; it
only acts when total system voltage gets too high. Stick a 'scope on such a system running even a 100AH car battery, it is informative
What is *not* a good idea is jump-starting such a bike system from a car with a running engine - because it will try to load-down the cars
(compartively- huge) alternator output and burn out; the cars alternator will do anything to maintain its voltage output, using field regulation, and
will win. If you must jump from another vehicle's battery, simply don't start its engine.
[Edited on 16/4/15 by The Huff]
bigfoot4616 - 17/4/15 at 09:49 PM
quote:Originally posted by russbost
A bit more tried & tested than capacitors!
5% discount for LCB just give us a ring 07905 879407
i'm in need of a new battery now, one of the terminals is broken on mine. current one is a bike battery on a 5VY R1 motor.
as its 99% a track car how small a lithium battery do you think i could get away with?
Recommended battery as standard for the 5VY R1 is the LIPO10A, CCA 210A £128.45, weighs 900g however you could certainly get away with something
smaller/lower CCA. Providing you're still running an alternator, then as soon as the engine is running the battery is no longer doing any work
other than recharging, so it's simply a question of having something adequate to start the engine & have sufficient reserve that if it
doesn't start on first few attempts then you are able to fault find without getting a flat battery in no time.
Simply for the above reason I wouldn't recommend going ridiculously small, the LIPO12E gives CCA of 180A at £115.90, so saves you a few bob, but
still 900g, smallest I could possibly suggest going to would be Lipo07A CCA 140A £104.95, weighs 600g, tho' pesonally I would only go that small
if I was going to have a backup/boost battery available for initial start
All above prices I can do 5% off the battery price & all the above INCLUDE P & P, what a lot of people seem to be missing is that prices &
CCA's are very similar to the Powervamp, but the LIPO's are around 1/3 of the weight!
bigfoot4616 - 18/4/15 at 11:45 AM
not even thinking about a powervamp, the standard bike battery has done me well for the last 7 years and it didn't look very new when i got the
car. i would just get another normal cheap bike battery but the LIPO's seem to be a relatively cheap way to save weight.
decision time now, the 210A or the 140A and backup battery. are any of the booster packs ok to use with the LIPO batteries? also if it fires up
immediately on the button which it always does i assume the 140A would still start it?
only downside i can see is if i read it properly i wont be able to use my ctek maintenance charger on one?
do you have both of the ones i mention above in stock?
rodgling - 18/4/15 at 11:57 AM
I have one of Russ's LIPO batteries, it's really good. Doesn't lose it's charge if unused for a long time, and easily starts my
3.2l engine, no issues with it in about a year of use. I've got the largest one which is 1.4 kg if I remember rightly.
[Edited on 18/4/15 by rodgling]
russbost - 18/4/15 at 01:37 PM
quote:Originally posted by bigfoot4616
not even thinking about a powervamp, the standard bike battery has done me well for the last 7 years and it didn't look very new when i got the
car. i would just get another normal cheap bike battery but the LIPO's seem to be a relatively cheap way to save weight.
decision time now, the 210A or the 140A and backup battery. are any of the booster packs ok to use with the LIPO batteries? also if it fires up
immediately on the button which it always does i assume the 140A would still start it?
only downside i can see is if i read it properly i wont be able to use my ctek maintenance charger on one?
do you have both of the ones i mention above in stock?
Yes, both in stock, but even if we go out of stock can normally replace stock next day. No problem with using any normal battery powered booster pack,
but don't use one of the big garage type mains boosters as you must not exceed 14.5V when charging & some of those boost chargers put out
around 18V. I'm sure the 140A would start it, but you may get a shorter life from the battery than normal (usually good for 2000 cycles, about 4
- 5 times that of lead acid). I've not used the ctek charger, as long as it doesn't go into an anti-sulphation cycle (which it
shouldn't because they automatically recognise that requirement IIRC) then it should be fine, if you have any doubts, just put a voltmeter across
it & check what it's charging it too, as long as under 14.5V it will be fine.
bigfoot4616 - 20/4/15 at 09:13 PM
think i'll go for the 12E as that's the best fit in the space i have.
my charger does have a desulphation cycle but if i understand you correctly it should still be ok, could you check the user manual at the bottom of
this link and let me know what you think?
if you could U2U me payment details and amount i will get payment sorted tomorrow or wednesday.
thanks
russbost - 21/4/15 at 08:03 AM
Theoretically these automatic chargers should only ever go into the anti - sulphation cycle if they recognise the battery needs it, but they were of
course designed b4 Li Ion batteries were around so you can never be 100% certain. However so far as I can see from the manual the anti sulphation
cycle is still only at 14.4V so can't do any harm.
