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Battery Choices and Information

159K views 323 replies 111 participants last post by  CrusaderTBC 
#1 · (Edited by Moderator)
SEE TABLE AT BOTTOM FOR CHOICES

DEAD BATTERY IN THE ELISE / EXIGE
If the battery is dead and the Remote Fob was used to lock the doors and arm the alarm system, the doors can't be unlocked using either the Remote Fob or the key. The method used, is to open the Engine/Trunk cover on the Elise and Exige and gain access to the battery, the alarm may not sound due to low battery voltage. Now apply a 12V power source to the battery, using either "jumper cables", "power pack" or a "battery charger", and then use the Remote Fob to turn off the alarm and open the doors. On the Exige the front "power post" can be accessed as an alternative. If the battery is disconnected before disarming the alarm, the system will switch over the the back-up battery and sound the siren.

LOTUS RELATED INFORMATION
1) Due to the risk of battery leakage in the trunk, replace the existing OEM wet (flooded) cell with an AGM battery, which can't leak, spill, & emits no flammable hydrogen gas under normal circumstances.

2) The choice between "weight" & "capacity" (Amp Hour)
If you track, then you may consider the battery weight to be the most important.
If you don't drive the car often, (especially in colder climates) and don't have access to a "battery maintainer", a greater amp hour (AH) capacity is desirable.

3) The Elise/Exige uses a "BCI group 26R" size battery, however a "35" will also fit. Batteries of other physical size will need a custom support.

4) The OEM "Exide X-tra" is European only model

5) The "Black" OEM has the reputation for leaking.

6) Wet cell batteries typically loose 1% of their energy per day, without any load applied.
AGM batteries will typically loose 1 to 3% per month, without any load applied.

7) Parasitic load on the battery is;
Alarm/Immobilizer OFF + Radio + ECU = 20.5ma
Alarm/Immobilizer ON + Radio + ECU = 42.5.5ma

SULFATION - THE DEATH OF A BATTERY
THE SYMPTOM
The first thing you notice is that the battery is either not accepting a full charge or not lasting as long as it used to. The main reason is that the battery is dying due to sulfation. During it's life, sulfate forms on the plates and can solidify, insulating them, and inhibiting the chemical reaction. The more a battery is neglected the quicker the sulfate forms, but eventually it is inevitable that it will kill the battery.

THE CAUSE
Batteries sulfate because;
a) Sit too long between charges. As little as 24 hours in hot weather and several days in cooler weather.
b) Battery is stored without some type of energy input.
c) "Deep cycling" an engine starting battery. Remember these batteries can't stand deep discharge.
d) Undercharging of a battery, to charge a battery (lets say) to 90% of capacity will allow sulfation of the battery using the 10% of battery chemistry not reactivated by the incomplete charging cycle.
e) Heat of 100 plus F., increases internal discharge. As temperatures increase so does internal discharge. A new fully charged battery left sitting 24 hours a day at 110 degrees F for 30 days would most likely not start an engine.
f) Low electrolyte level - battery plates exposed to air will immediately sulfate.
g) Incorrect charging levels and settings. Most cheap battery chargers can do more harm than good.
h) Cold weather is also hard on the battery. The chemistry does not make the same amount of energy as a warm battery. A deeply discharged battery can freeze solid in sub zero weather.
i) Parasitic drain is a load put on a battery with the key off.
j) Battery voltage falls below 12.4V

THE SOLUTION
Simply keep the battery fully charged by either regular driving or keeping it on a "maintainer". Do not use a "trickle charger" which charges constantly, irrespective of the battery condition, and can overcharge. A "maintainer" monitors the battery condition and when a full charge is detected it automatically goes into "float" mode, meaning it will charge upon demand only.
De-sulfating (conditioning) the battery is possible if you have a charger, or "maintainer" with that function. It is recommended to de-sulfate regularly and though a number of cycles in order to keep the plates clean and prolong the battery life. If the sulfation has progressed too far, it may not be possible to rectify. One such maintainer/conditioner is the BatteryMINDer Plus and from the same company is the conditioning only BatteryMINDer On Board Restorer-Conditioner

BATTERY TESTINGThe best method is "load testing" (many places that sell batteries will do this test), but without suitable equipment the following voltage measurement method can be used;
Measure the battery voltage across the two battery terminals.
Although a vehicle battery is called a 12 volt battery, 12 volts is considered discharged.
Before measuring, the "surface charge" has to be removed. The surface charge, which results from recent charging, will make a deficient battery seem good. The best way to remove the surface charge is to leave the battery for 6 to 12 hours in a warm area. Alternatively, with the engine off, the high beam headlights should be left on for 5 minutes, turned off and then left for 5 to 10 minutes.
100% charged & healthy battery will measure 12.66V.
75% charged will measure 12.45V
50% charged will measure 12.24V
25% charged will measure 12.06V
Below 12V a battery is considered discharged
A shorted or dead cell will read 10.5V
Check the battery cable connections for a secure fit or signs of corrosion.
Typically, an alternator will not bring an AGM battery to a full charge condition.

THE ALTERNATOR
BASIC ALTERNATOR TEST
At idle the voltage across the battery terminals should be between 13.5 & 14.5V
At 1500rpm the voltage should not exceed 14.8V

ALTERNATOR WARNING LIGHT
Check that the alternator belt is not broken or slipping.
Check that all battery & alternator connections are secure and clean.
The red ALT light, basically, means that either the alternator output voltage is lower than the battery voltage, or the battery voltage is lower than the alternator output voltage. If the light gets dimmer as you rev up the engine, then you most likely have a problem with the alternator. If it gets brighter, then the battery is most likely bad.

ALTERNATOR PROBLEMS
Many times one or more diodes in the alternator rectifier assembly will have failed, causing a drop in the unit's output. The alternator will still produce current, but not enough to keep the battery fully charged.

JUMP STARTING FROM ANOTHER VEHICLE
The Elise/Exige does not start easily when being jump started. Frequently, a series of clicks will be heard from the starter solenoid, but the starter motor will not operate. I have had success with the following method;
Connect the cables, making sure you have good connections on both ends.
Start the other "donor" vehicle and let it run for 5 minutes at high idle, about 1500 - 2500 rpm, this will give your battery a boost. Now with the other car still running try to start your car.
 

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#2 ·
man, this is so helpful - thanks a million.

i assume that the stock Elise battery is at the top of the list?

also, how nerdy does it look to ask for a lightweight battery for Xmas?

-"You really have a battery on your wish list?"
-"Well I need to lose 20lbs of body weight"
-"That's nice, son"
 
#5 ·
weights

The Odyssey batteries are usually lighter than the advertised weights. I just weighed a PC1200 and it is 32lbs 12.3 oz. and definitely has more reserve capacity than the oem 45ah battery. I can post actual weights of the pc925 and pc625 later. The older Voltphreaks 3lb battery was actually 2lb 12 oz but the latest version might be heavier.
 
#7 ·
Remember that Odyssey batteries can be had with or without the metal jacket. I think it can add up to about a pound or so.
 
#8 ·
subscribed. Think I'll be needing a battery within the next year. I do drive a lot so it's been holding up well, but as of lately I have not been driving the car every day.
on an almost related side note my factory BMW battery lasted 10 years when the car was driven every day. (and for quite a miles around 100 miles per day). Like most other parts of the car sitting is harder on them than using them.
 
#9 ·
I suspect Braille gets their batteries from Deka, as Deka is a major manufacturer and their batteries seem to have the same form factors.

On average a Deka is approx $100 cheaper than Braille. But Braille does claim higher capacities, so perhaps there is a difference? :shrug:
 
#10 · (Edited)
Lets be clear about something.

If you are looking for a battery that WILL FIT in the stock area, you need to buy one that is the same size as the stock one.

All the other batteries will require brackets that you will have to install in the car.

ORDER YOUR BRACKET FIRST. I ordered a PC680 and then found out every supplier - Sector 111, Force Fed, etc - were all out of brackets. I kept getting promises that the brackets would be in any day, in the mean time I went six weeks without a working battery setup in the car.
 
#11 ·
Hi all,

Based on some calculations I did, using a 35mA draw (15mA immobilisor, 20mA alarm), it appears that an Odyssey PC680 (what I myself have now - it came with the car) will reach 50% capacity in only 6 days, under ideal conditions (80F). Anything colder, and 50% would be reached quicker.

The PC680, according to Odyssey, is not designed for reserve capacity. Assuming that starting the car requires at least 150A, a PC680 rated at 300CCA would not last more than 7 days before it struggles to start the engine.

The PC925 should reach the 150CCA point after around 17 days.

The PC1200 should reach the 150CCA point after around 30 days.

These calculations assume a relatively linear power drop, and in an AGM-based battery should be relatively accurate. Wet cell would probably be more unpredictable. The calculations seem to fit the relative experiences with the different ratings I have had.

Note that CCA is taken at zero degrees celcius (32F), so under "normal" weather conditions, you should be able to gain a little more time. However, since the reserve power ratings are done at 80F, it may compensate for this gain.

DISCLAIMER: These calculations are an approximation, and the age of the battery, condition of the charging systems, use and abuse of the battery, etc, can (and will) have a major impact on the figures.

If weight is a major concern for you at the track, but you drive on the street too, then I'd suggest getting a PC680 for the track and a PC925 or PC1200 for the street. Just swap the battery when you get there. ;) AGM-type batteries can be stored up to two years (make sure it's fully charged before storing). This will ensure the best battery life overall - IMHO, PC680's on the street cycle too much, reducing their lives significantly as the battery should always be kept nearly fully-charged (unless you have a power outlet nearby with a good battery maintainer!).

One other thing - you should also ensure your regular charger is designed for AGM-type batteries.

HTH!

Thanks!

S.
 
#21 ·
Based on some calculations I did, using a 35mA draw (15mA immobilisor, 20mA alarm),
Except...

I seem to remember that the system pulls 10 mA with the imobilizer on and alarm off, and 15 mA when the alarm is activated along with the imobilizer. The alarm being active adds 5 mA draw to the immobilizer only - the two amounts are not added together.

Even if I'm wrong about the 10 and 15, and it's really 15 and 20, they still are not added together to get 35 - it's one or the other.
 
#12 ·
Intersting info Rom, but I believe there really is no "accurate" way of calculating how long a battery will last until such time that it is incapable of starting the vehicle, so many variables. Even identical batteries will have different durations. The best way, is to look at the AH rating as just a guide to compare different batteries e.g. a 20 AH battery should last about twice as long as a 10AH. Even a fully charged battery at 12.66V will dip to around
9.6V under starting conditions. But, I agree that a small, light weight battery can not be expected to nomally last for weeks with an appreciable parasitic load. Incidentally, I believe that the total parasitic load on the vehicle, with the immobilizer and alarm set was 20ma, with only the immobilizer it is 15ma, not combined, but I will check that tomorrow. I also believed that included in that 20ma is a small 7ma from the ECU. This total does not include any radio loads.
Michael
Batteries are my friend :)
 
#14 ·
Yep - hence my disclaimer :) . The time values are only meant to be an approximation.

I'll measure it on mine too... If the parasitic is only 20mA total, then the time intervals should be quite a bit longer (I searched through the forums for the parasitic value). I'd be interested to know your measured values - I'll measure mine too for comparison. It would be good to see if our cars are all the same, and what the difference is between model years and Elise vs Exige.

Thanks!

S.
 
#15 ·
Oh yea, and I just installed an Optima 35 yesterday. Although it's quite a bit heavier than my PC680, I was fed-up of not being able to drive when I wanted (due to consistant flat batteries)!! Since I moved to within walking distance of work, I rarely drive any of my cars now (wife & kids means when I do drive, we take the Evo)... The Lotus goes 2-3 weeks without moving, and I don't have an outlet nearby.

The slight weight saving is more than made up by my lighter SSR's and Larini ;)

I'll report any issues the Optima may have in the coming months.

Thanks!

S.
 
#17 ·
Good luck with the Optima's guys. I had one a few years back that was garbage. It was in a car stored in MI for a couple months in the winter and was deader than could be when it was time to come out of storage and would not take a charge. Several other guys that got them from the same stereo shop had the same thing happen. We all got left high and dry on any kind of warranty either and could never get a response from anyone at Optima.

Hope they aren't as big a pile of garbage as the batch my friends and I had an experience with.
 
#18 ·
Mine is working OK. I have had it for a few months now and drive the car about once a week. The longest I went without driving it is about 2 weeks
It starts up fine without any problems. I left the radio on with the old battery for about 15 minutes and it killed it.

I cant complain about the stock one, it lasted over 4 years for me.

Got the Optima at Costco. They have a pretty good return policy, so if it dies on me I don't think I will have a problem.
 
#20 ·
When I used to charge the stock battery, I was quite concerned over this. All of the other cars I have owned with a battery in the trunk (3 BMWs and a Turbo Esprit) all had batteries with a vent hose attached that directed any hydrogen produced or acid vented through the hose which passed through a grommet in the trunk floor to the outside of the car. With no vent hose to the outside on my Elise, I was always careful to leave the trunk lid open and to check for spilled acid around the battery. With the new sealed AGM batteries, there is no trouble with the lack of a proper vent to the outside of the trunk, but out of habit I still leave the trunk lid open when charging the battery.
 
#26 ·
I think I need a new battery soon so was looking into getting an AGM battery. I don't want to deal with a bracket or mods and I'm not fast enough to where weight really matters. Looking at the chart, I'm going to guess that the Odessey PC1200 is the one I want ?
 
#27 ·
Do a search on the PC925, as it's not that hard to put in and weighs about the same as the original battery. The 1200 is heavier, which might be a problem with the original mounting points. You only have two nut plates that are each held in place with two rivets to fiberglass, so this might weaken those attachment points over time.
 
#29 ·
The Odyssey is the really the only way to go. There are several posts about making a lock down system. I made a lockdown system with Stainless Steel strap.

I and many of our LOONYs use the 925. Others have used the one half that size...I think the 680. I use the 680 in my Seven.

eBay Motors: Odyssey HDB925 Battery Hold-Down Bracket Summit (item 330317624266 end time Apr-25-09 11:23:32 PDT)

eBay Motors: Odyssey HDW925 Battery Hold-Down/Mount Steel Natural (item 330317624294 end time Apr-25-09 11:23:33 PDT)
 
#31 ·
I just got my Braille 106 battery (6.6 lbs). I use my exige as a daily driver and needed a replacement for my big, exhausted 40 lb marine battery (prior owner's selection). The specs on the battery made me a little cautious... 10 amp hours... I had fabricated a stock battery bracket (it was nice, looked IDENTICAL to the original), but then found my OEM bracket under the carpeting in my trunk. So, I sawed some grooves in the bracket I made so that I could bend part of it around the smaller battery. I also used a few additional washers, a zip tie, and double sided sticky tape to mount the battery, and banged my aluminum bracket down a little to widen it. The bracket clamps against the side of the battery nice and hard and it weights 7 lbs, so it isn't going anywhere. I have enough scrap metal to fabricate a better bracket if I needed.

I expected this 10 amp hour battery to be "smart", by which I mean: include some type of trickle drain prevention so that my alarm doesn't kill it. I'm assuming this protection exists because every time I turn my car off and leave it for a few minutes, my clock resets to some random time of day.

I may call up Braille and find out if there's a relay inside the battery that opens in certain situations. If there is, then I'll put a tiny 12-14V battery (like a 1AH 12V battery pack) in parallel with the main battery.

If there is a relay, I HOPE someone at Braille knows if I can use a small parallel battery to keep the clock alive. If the Braille battery has a relay, maybe it won't open if it's equillibrating with another parallel battery. Any thoughts before I harass Braille?
 
#32 ·
The Braille 106 does not have a disconnect relay. Braille do make an auto-disconnect, called the "power protector", it has a yellow cylindrical top to it, check if you have it. If the battery was disconnected the alarm would switch over to it's back up battery and sound.
Cheers, Michael
 
#33 · (Edited)
Ahh. That's what that is... Everything seems to be OK now that the battery has been fully charged. Thanks, Viper, that woulda been a long back-and-forth with Braille, culminating with lots of confusion.
 
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