28 replies to this topic

[sheepy89]

the benefit of a second battery with controlled charge/isolation is you can use the second battery for audio, fridge, alarm etc while the engine is off, then not having to worry about returning to the car with a flat starter battery.
Also useful if for some reason you do have a flat starter battery, flick the relay on and you've got a built in booster pack!
[/quote]



that way your coverd either way. its a win win situation. sounds good to me

[david@skeggyminis]

i have a shelf built above the o/s/r shock and the scooter battery sits on it so takes up know room in the boot

[sheepy89]

if you run your audio through the second battery do you have to change how its wired up? like would you have to wire it directly to the other battery?

[pbrain]

if you run your audio through the second battery do you have to change how its wired up? like would you have to wire it directly to the other battery?

yes, you'd have to cut & insulate the existing permanent & ign live going into your ISO connection. Put a small guage cable from 2nd battery (~20A handling) with a fuse to the RED & YELLOW going into the head-unit. The benefit (downside for some) is you have the head-unit playable with ignition on or off.
Your 'remote out' cable will still work with any device attached to either battery because of the shared earth/ground. I always put 'remote out' to a relay, slight fault or surge will pop the little transistor inside the head-unit (typically max 500mA).

[sheepy89]

when you say a small gauge cable what does that mean (sorry not very good with terminology) and when you cut the red and yellow wires from the ISO connector do you wire them into one wire to the battery or two wires going to the battery?

sorry about this dont want to make a hash of it so trying to cover all posibilities haha

cheers for your help

sean

[pbrain]

when you say a small gauge cable what does that mean (sorry not very good with terminology) and when you cut the red and yellow wires from the ISO connector do you wire them into one wire to the battery or two wires going to the battery?

sorry about this dont want to make a hash of it so trying to cover all posibilities haha

cheers for your help

sean

'small gauge' means 'thin cable', where as 'thick gauge' typically refers to high-power cables such as 8 gauge upto 0 gauge. newbies to cables get confused by the cable numbering, 8 gauge is thinner than 4 guage etc. typically there's 4x 4 gauge cables to a 0 gauge & 8x 8 gauge cables to a 0 gauge. think of it like fractions (1/2 is larger than 1/4).
You can connect the yellow & red at the ISO and use just 1 cable going back to the 2nd battery, as mentioned before try and use a cable with around 20 Amp handling or better, with an inline 20A fuse as near to the battery as possible.

[sheepy89]

question time lol

to wire up a few smaller batteries together is it a case of just joining the + and - on each battery together?

if so would the split charger charge all the smaller batteries?

and then im guesing id have to wire the stereo up to the end battery?

can anybody link me to a website i can get a few small batteries from? i want them to fit under the rear seats.


sorry if there dumb questions lol

cheers

sean

[pbrain]

question time lol

to wire up a few smaller batteries together is it a case of just joining the + and - on each battery together?

if so would the split charger charge all the smaller batteries?

and then im guesing id have to wire the stereo up to the end battery?

can anybody link me to a website i can get a few small batteries from? i want them to fit under the rear seats.


sorry if there dumb questions lol

cheers

sean

If you're going to have multiple batteries (assuming they're all 12v) then connect all the (+) together and the (-) together (parallel), the voltage will remain the same, the Ah (capacity) increases with each battery added. ideally use the same batteries with the same history (example new 4x 12v 10Ah which will be the same as a single 12v 40Ah battery). Also to make it safer, put a fuse holder on each (+) terminal, unless you can 100% certain that the connections will not fail/come loose. Also, the (-) don't have to be linked to each other, they can be individually grounded (preferably to one point of the chassis, making sure the connection is as close to 0 ohms as possible)
The battery bank should charge as normal, obviously the more batteries you have, the more current the alternator has to supply.
You can take the stereo supply from any point of the battery bank...first battery, middle or last one.
Lastly, batteries, i'd keep my eye open on ebay using keywords such as "alarm 12v battery scooter" i was luckliy enough to buy a new set of 12v 8Ah's for a toy motorbike off the car-boot for £3 each!

PS: if you happen come across some cheap new 6v batteries, you can use these (in pairs) just link the one battery's (+) to the other battery's (-) (called 'series'). the Ah stays the same but the voltage doubles (example 2x 6v 15Ah becomes 12v 15Ah linked). and if you get say 4 or 6 of these, then it gets a bit more complicated. firstly, make pairs (ie 2x 6v pairs or 3x 6v pairs), then link the remaining (+) and (-)'s together as though they where normal 12v. (this is called a 'series/parallel' connection...very similar to wiring subwoofer banks up) so your 4x 6v 15Ah makes 12v 30Ah & the 6x 6v 15Ah batteries becomes 12V 45Ah.

Sorry for any confusion or if i come across as tedious, i try to explain how it works! If someone can draw the examples & upload that would help others out.

Edited by pbrain, 05 September 2010 - 12:26 PM.

[xBR4DLEY]

As someone said using a battery from a electric scooter I thought couldnt you use a moped/motorbike battery? Or are they too big/small for whats needed

[sheepy89]

thanks for all your help i was looking at puttin the extra batteries under the rear seat behind a kickboard so could do with the smaller ones.

ill keep my eye out on ebay then for any that are knocking about.

and dont worry i like people explaining things thouraly as it makes it less likely that ill screw it up haha

cheers again no doubt ill come up with some other questions sometime soon lol


sean

Edited by sheepy89, 05 September 2010 - 06:13 PM.

[sheepy89]

well iv been looking on ebay and cant find anything small enough with a big "ah"

any suggestions?

cheers sean

[pbrain]

well iv been looking on ebay and cant find anything small enough with a big "ah"

any suggestions?

cheers sean

these are ideal...

http://cgi.ebay.co.u...=item27b4edeab6

it depends on your budget & what you intend to use them on, one of these should run a typical HU for 30-60mins at average volume. Forget putting a 1000wRMS amp on though!

[sheepy89]

i was planning on running my whole audio system through the other batteries so 16cm component speakers and putting 2 10" subs in the boot so could do with something that can handle it all. i mean i dont mind having to get a few seperate batteries and wiring them together just dont want to be paying loads for them

[sheepy89]

just wondered how much "ah" i would need to run my audio system through the seperate batteries?

cheers sean