Author Topic: adding a secondary battery (Read 1878 times)

craziechild · « **on:** January 19, 2007, 09:52:45 PM »

hi all....

well i am not facing any light dimming problem but planning to add a secondary battery just for my amps cuz will relocated them to the trunk from the front seat... so thinking of saving some money on the wires and at the same time be assured with enough power supply for my amps...

currently i hav upgraded my stock alternator from 75A to 95A... volt meter reading is constant at 13.5 when idling and sometimes can go up till 13.8 while driving...

so first question... what else to i need to look on before i add another battery? and how to wire the batteries? parrarel or series? planning to use a dry-cell and locate the battery at the trunk...

any advise or comment or criticism or experience sharing are welcomed...

thanks....

wengweng · « **Reply #1 on:** January 20, 2007, 09:46:06 AM »

Can pull the +ve to the +ve.
-ve can try a new ground at the boot first to save cable. If got aeroplane, then only try pulling the -ve from battery to battery to see if it is battery issues
Some use isolator to isolate from battery to battery, or from alternator to battery 1 to battery 2. Do you plan to put in isolator ?

Having said that, but why do you think a second battery would help ?

craziechild · « **Reply #2 on:** January 20, 2007, 06:56:16 PM »

what is an isolator?

adding one is because my car sometimes hard to start in the morning... at first thought changing the alternator would help on recharging my current battery... but the problem still presist but better already then change my battery to NS70 but still the same problem... so thinking of adding another battery to try see if it helps...

cheers...

wengweng · « **Reply #3 on:** January 20, 2007, 08:46:29 PM »

Isolator looks like this one. This one is multi battery isolater, wired from alternator then to battery 1 and battery 2. There is another type which wire from battery 1 to isolator then to battery 2. You guessed it, it is used to isolate (of course !

) the 2 batteries....hahaha

If you dont have an isolator, it is still ok. Just that the 2 batteries would be connected. Last time I took off the isolator and also running ok.

Try if the second battery would help improve the morning starting. Personally IMHKNNO, 2nd battery does help in SQ. But dont ask me to explain because I can't.....

netken · « **Reply #4 on:** January 20, 2007, 08:47:36 PM »

the one wengweng show is the isolator using electronic cap ...

there is another common isolator using a mechanical relay also ...

mnkh27 · « **Reply #5 on:** January 20, 2007, 08:53:54 PM »

I'd just upgrade the alternator and change to a deep cycle battery. Kau tims. It would be good to check if your existing power cables are in good condition and thick enough.

craziechild · « **Reply #6 on:** January 20, 2007, 10:55:55 PM »

erm.... tht pic looks kinda small and i couldnt get a real good picture of what is tht thing... but if i dun use an isolator would it do any harm towards my car electronics? and one more thing is will i strain my alternator too much by adding another battery? do you guys hav something like a calculation formula to calculate this?

about the wires... from my alternator to my battery i have not change tht... still using the stock wires... but will look into it since mike mentioned it...

and well... last i heard a deep cycle battery is kinda way too much for my small budget...

and lastly... thanks for all the inputs...

cheers...

wengweng · « **Reply #7 on:** January 21, 2007, 12:03:13 AM »

mike, he said he has changed the alternator to 95A and battery to NS70, but still got problem. Yeah, maybe craziechild should check out the new alternator. Is it recon or new ? Installation ok ? if it is tilted with the belt, it would affect the performance also. I had the same problem with my new 120A alternator, and have to change back to the 90A one last time.

Dont bother about the isolator first lah. Since you have the battery and the power cable, just lay them in for trial to see if it works. If unsure, get an experienced installer to do it for you.

BTW, how many watts of power do you run in your sound system ?

mnkh27 · « **Reply #8 on:** January 21, 2007, 01:33:49 AM »

I changed my alt to a new one. Didn't feel it was a good choice to purchase a used or even reconditioned unit since the labour to change is the same. Furthermore, we're expecting to keep the alternator for at least 5-10 yrs problem free and healthy. Without knowing the history of a used alternator, I wouldn't really recommend buying one unless you're on a budget and you're not into car audio/ICE. Recond units are for people with a spoilt alternator and have no budget to buy a new one.

craziechild · « **Reply #9 on:** January 21, 2007, 12:57:00 PM »

total power i think is 500w rms+/-... my alternator is half cut ones changed because my stock alternator kong... was trying to find a new ones but only got 75A so i took the half cut ones... actually wanted a 120A but search four major spare parts place all dun hav... so end up with the one i am using... installations was jus plug and play... cuz the connector and mountings were the same...

weng weng... well what you mean by "tilted with the belt"?

cheers...

wengweng · « **Reply #10 on:** January 21, 2007, 01:18:00 PM »

If it is not original and exactly the same as the stock alternator, you have to modify the mounting for the alternator. If it is not aligned properly, the polley of the alternator and the engine is not perpendicular/vertical. Hence the belt will have some friction and the charging would be affected. So although it has higher capability, but the friction caused it to not function optimally. Last time my 120A alternator is worse than my 90A, because of the size of the alternator and my mechanic could not align it to exactly 90 degree. Of course like mike say, if it is used, you are also not sure how efficient the alternator is.

500w total power for sound system is still ok with 1 battery. I guess your problem is your charging system and second battery would not really help. But no harm trying the 2nd battery since you already have all the component

Bert · « **Reply #11 on:** January 21, 2007, 04:09:36 PM »

mmm, what car is this? Cuz if your car is stock with a 75A alternator and you upgrade to a 95A alternator, you will have an extra 20A vs the original design. Highly likely your 'new' alternator is not giving out the rated power...

craziechild · « **Reply #12 on:** January 21, 2007, 05:54:26 PM »

my car is plotong wira...

well my foremen said both the alternator use the same cover... we did some measurements also... and the mounting and degree of both the old and new alternator is the same... its from another mitsubishi car... what car not too sure la... but confirm is mitsubishi....

any idea how to measure whther they are giving out the rated power? use multimeter?

cheers...

netken · « **Reply #13 on:** January 22, 2007, 11:12:24 AM »

just my 2 kupang ... since i have been playing from one batt to triple batt, relay isolator to electronic isolator, wet batt to Maintenance free batt to dry cell batt to gel type batt and alternators from 80A to 120A and searching for a 150A .....

based on what i read, i dont think u need to upgrade to a 2nd batt, since you do not need such high current for your entire setups .... how i know? because my setup also does not require such kraxy powerplant setups ....

if u have upgraded your alternator to a healthy 95A, good news! you can now charge your battery even faster, give or take 30% much faster to replenish your load .... and if u have a NS70 batt, which is sufficient for a proton wira, i dun see why u need a 2nd battery .....

some things for u to consider if u have a 2nd battery :

1. your 95A alternator may not be able to charge both batteries at the same time to the limits.
2. advisable to have both batteries identical in size, age and type.
3. using an isolator which also have a shelf life although longer.
4. car pull or engine efficiency in your engine will be reduced, no more power pick-up and top speed.
5. higher friction and of course higher heat being created in your engine bay.
6. putting a 2nd batt in boot require investment, i.e. no fumes that is only gel or cell type, again if u want to put the same type of batt in the engine bay, 2 new batteries, more investment.
7. possibility of even more aeroplane sound, troubleshooting problem.
8. possiblity to add caps or voltage devices to control high voltage, again investment.
9. pulling cable assume 0awg to boot for charge, again investment.
10. extra weight on your car, need more dragging power, increase full consumption.
11. possibility to prepare 2nd batt place, ie. woodwork, plexi, etc ... more investment.
12. possibility of an explosion and becoming ....

..... PRICELESS!

and yada yada yada .... how i know? because i've been there, done just that' ...

listen to me and dun spend unnecessary money, time, power, heat, cables, batteries, petrol, etc ...

would still be glad to advice whatever option u choose... cheers!

no lasering allowed, my own kupang ...

Oldskolboyz · « **Reply #14 on:** January 22, 2007, 01:25:44 PM »

haa haa.. every morning difficult to start kaa? If Ur Wira model 2001 & above just got 1 solution..

Your Throttel Body need services.. this disseas only happen to New Wira - 2001 onward.. U also can services by your self.. the new ECU very Sxxxxxk & U can't tune it, not like Siemens/MMC ECU (<2000) the throttle body can tune...

craziechild · « **Reply #15 on:** January 22, 2007, 06:52:57 PM »

thanks for the list of consideration netken... will look into it before i decide to go on with the project...

OSB... my car is 97 wira 1.6 le... mitsu ECU...

Pras · « **Reply #16 on:** January 22, 2007, 08:06:54 PM »

same topic

http://www.carsound.com/columns/navone/nav0003.shtml

craziechild · « **Reply #17 on:** January 22, 2007, 08:17:50 PM »

hmm... thanks... more to consider after this...

or jus curious... does adding a cap help?

thanks pras tai low...

Pras · « **Reply #18 on:** January 22, 2007, 10:16:45 PM »

nope.

Oldskolboyz · « **Reply #19 on:** January 23, 2007, 08:01:27 AM »

Quote from: craziechild on January 22, 2007, 06:52:57 PM

OSB... my car is 97 wira 1.6 le... mitsu ECU...

1.6 should be ok, coz I own 1 before (1st car).. sale due to 1 FXXXker kiss very bad until boot also koyak at Jln Kuching.. aiya almost 10 years oledi.. send to workshop for Top Overhaul laa.. cost around <Rm400

louisl · « **Reply #20 on:** January 23, 2007, 08:48:19 AM »

OSB... my car is 97 wira 1.6 le... mitsu ECU...
[/quote]

mayb u try to check ECU, coz mitsu ECU always suck,
last time my wira 1.5, i modifica half mistsu body 1.6, after half years the ECU got problem untill i change the ECU for 3 times and now sell my car.

craziechild · « **Reply #21 on:** January 23, 2007, 08:03:14 PM »

will do to see if it helps...

at the mean time i thing this thread can close already... cuz hear the sifu warning liao i also dun dare to try adding another battery...

btw... thanks for the warning... you guys are the best...

cheers...