Modern car batteries in older Jeeps

[V]

The longest lasting battery I have had in my 1993 XJ was a Mopar branded low maintenance battery that had removable caps for topping up the electrolyte. I had 14 years of use from that battery. Almost every other modern 'AM058R' size battery I have fitted since has managed two years at most with degradation noticeable after one year. As I don't use my Jeep daily and I don't plug it into a maintenance charger every time I park it at home, I can't make a claim on the useless battery warranty.

 

My 2001 XJ has a UK type 096R battery as original equipment and manages to go a little longer than two years but degradation is still noticeable after a year. The AM058R (UK type 113) is 50Ah/530CCA, the 096R is 75Ah/650CCA . I would like to fit the bigger 096R into my older Jeep but it wont fit due to the alternator location. I have had enough of buying replacement batteries every two years. I have decided it's time to fit a bigger battery that gets closer to the performance of the 096R size even if I have to make new battery and alternator cables to deal with the back to front terminal post layout of the commonly available battery options.

 

I have been researching all types of modern battery technologies and I found some interesting information concerning modern battery life expectancy. From Exide's Summer Maintenance document I can see that under bonnet heat could be the reason why my batteries last such a short time. My Jeeps are parked outside, not in shade and XJ engine bay temperatures are always hot.

 

My current AM058R is a Numax, but reading the technical data for both Numax and Yuasa for this battery size reveals a recommended maximum charging rate of just 4 Amps! So the standard 90 Amp alternator in my Jeep is going to give this battery a problem in normal use. The charging amps while driving is easily going to rise above 4 Amps. Sadly, my smart maintenance charger is also too powerful at 8 Amps, which it automatically starts off at when recharging. Looking at the internal design of these calcium batteries the lead content is reduced compared to designs from the 20th century and is often presented as a mesh grid instead of a plate. I think durability during recharging is a big part of the short battery life I have been experiencing.

 

So what can be done?

 

Change of battery technology

I think the flat plate AGM technology used for stop-start vehicles has progressed so well within the top brand 'conventional' battery manufacturers that they now out perform (on paper) Optima spiral wound AGM batteries. The only real advantage I can see for buying an Optima now is the freedom to mount the battery in any orientation. The flat plate AGM batteries are mostly spill proof but I doubt you could mount them on their sides like an Optima. The deep discharge and frequent heavy recharge rates should be better than a standard calcium battery. I'm not choosing lithium based batteries because of high cost and fire risk.

 

Change of battery size

Installing a battery with the biggest physical case that will fit in the available space will achieve higher Ah and CCA.

The AGM stop-start variants of 027T and 075T are between 60-62Ah and 640-680CCA which is close enough to a regular 096R. I just need to confirm that I have enough clearance for the 1/2" taller battery. Going out to buy some plasticene later to put a 2" blob on the existing battery to see what happens when I close the bonnet. If I cannot find a reversed terminal layout ('R') battery then I will have to make new power leads for it.

 

Keeping the battery cool

Some things I have to consider:

• Hood vents or an after-market vented hood
• Raising the hood at the hinges to create an air gap near the base of the windscreen
• Insulating the battery
• Realising that the 2001 had a square hole in the inner wing that was probably to allow hot air to escape. I have covered the hole with a plate for a battery isolator switch. I might have to rethink that installation. There is no similar hole on the 1993.

 

Automatic battery maintenance charging

As my Jeeps are both parked outside, the simplest solution is probably to use solar charging. A less than 50W flexible solar PV panel mounted on the roof with a charge controller inside and up to two 25W filament bulbs as an excess charge sink.

 

[Ludders]

And just add another iron to the fire... EFB (enhanced flooded battery).

 

Less fussy with charging than the AGM, and cheaper too...

[BLUE STAR]

Easily get 5-6 years use out of my Optima yellow top in my JK 2.8 (touch wood)

Connect a C-TEK charger to it every 2 weeks using AGM/Snowflake setting, to keep it fully charged, as I've read that continual use of  a battery in poor condition could damage the TIPM (opinions welcome on this one)

Get it checked out spring & autumn at local tyre shop that use a Midtronic's tester to monitor condition & alternator charge with printout to keep for comparison.

 

[V]

4 hours ago, Ludders said:

And just add another iron to the fire... EFB (enhanced flooded battery).

 

Less fussy with charging than the AGM, and cheaper too...

I had initially discounted these based on slightly lower CCA compared to the equivalent size as an AGM. However, reading the Exide EFB info they reckon their carbon equipped batteries sulphate less and have twice the level of charge acceptance as conventional batteries. At just 50p more than the Numax AM058R, I think it is worth making a new set of battery cables to try an Exide EL600 (027 EFB). What caught my eye was the claim 'Optimal operation in engine compartment'. I wonder if this means heat tolerance

 

Plasticene test tomorrow.

[V]

3 hours ago, BLUE STAR said:

Easily get 5-6 years use out of my Optima yellow top in my JK 2.8 (touch wood)

It has a charging system specifically designed for that battery. My XJ was designed for maintainable lead-antimony batteries which are no longer available new. Zero maintenance lead-calcium batteries don't last long because they cannot be topped up and sulphate too quickly if not driven daily. The ancient XJ engine management does not have a desulphation cycle for alternator charging requiring regular use of a mains charger that does.

 

I have got a hand held electronic battery tester now so I can do a condition report every week with the new battery.

[Ludders]

8 hours ago, V said:

I had initially discounted these based on slightly lower CCA compared to the equivalent size as an AGM. However, reading the Exide EFB info they reckon their carbon equipped batteries sulphate less and have twice the level of charge acceptance as conventional batteries. At just 50p more than the Numax AM058R, I think it is worth making a new set of battery cables to try an Exide EL600 (027 EFB). What caught my eye was the claim 'Optimal operation in engine compartment'. I wonder if this means heat tolerance

 

Plasticene test tomorrow.

 

Some car manufacturers are moving away from AGM...

Hybrid & Electric vehicles are going to regular lead-acid, as the quick recharge of AGM is not required.

Ford, Nissan & Renault (are 3 I know of) have moved back to EFB as they are more reliable, longer lasting, and easier to charge.

[jerryg]

Optima (red top) from Tanya Batteries.

7 years life - no contest, IMHO!

[V]

7 years is very good. My JKU had a yellow top as original equipment and never let me down. Modern AGM batteries for stop start have a higher Ah which attracted me to them but I think I am going to buy an EFB next time.

[frosty]

i never get more than 3 years out of an Optima yellow top (original fit) in my diesel JK, lost count how many i have bought. 

[Caroline12]

I have seen a lot of different batteries for work and starting engines and quite honestly the most reliable long lasting batteries I have used are Yuasa. 
Yuasa, I think also make Halfords batteries, when i needed to replace my battery in Daisy, I put in a Halfords AGM battery, 5 year warranty I think. Daisy really only runs at weekends, she starts first time every time. 
 

I also put in the Yuasa AGM battery in my camping power pack. I charge the power pack and @spookie the aardvarkdiesel Jeep with a 20W Halfords solar panel battery maintainer £35, this has worked a treat and keeping his Jeep battery at 12V over this winter. It took his dead battery to good condition in the summer. 

 

Daisy and my work van batteries are all insulated from heat, so I would defo insulate them or extra ventilation. 
 

I put in the best battery I could, I chose AGM type. I won’t touch lithium batteries, thermal overload and fire issues and killing children to mine the materials. 

[V]

6 hours ago, frosty said:

i never get more than 3 years out of an Optima yellow top (original fit) in my diesel JK, lost count how many i have bought.

Do you use a battery maintainer or disconnect the battery when not in use?

[digger]

I'm electronically Neanderthal!  

I buy all my batteries from Groves Batteries  and have done since the 60s!  They sell Exide and I buy whatever they tell me is the most powerful and long lived I can fit to the car!!   Over the years the warranty length has reduced, now 4 yrs but it doesn't seem to have made any difference!  Once any battery is  8-10yrs old I use them for my electric fence and other things until NBG and then get a tenner for them at the scrappie!   When I bought my  WK  (7yrs ago £100) and my YJ (6yrs ago £80) I fitted new batts.  Both still going strong at mo!

I like the idea of keeping things cool! I have considered fitting louvres to the top of the bonnet but its all work  and as I haven't had an overheating issue I haven't done it.

I also note that the WK had a rotted battery insulator 'jacket' which I threw away. I thought it was for keeping the battery warmer in extreme cold like Alaska! Some of my past Jeeps had these as well.

I note Caroline mentioned Halfords batteries. My last 'fence' battery packed up about a yr ago. As I had non to 'retire' I bought a 'Halfords' from the scrappie for £15 . I always look for newest date combined with best charge in the pile! Its now about 3yrs old and going strong!!

I do start and warm up any car that has not been run for a week or so. I do not disconnect when not in use,  only if I have to(like doing a weld)

Edited March 9 by digger

[frosty]

10 hours ago, V said:

Do you use a battery maintainer or disconnect the battery when not in use?

yes, i have a C-tek charger on it. and it is usually garaged. 

[Caroline12]

 

15 hours ago, V said:

Do you use a battery maintainer or disconnect the battery when not in use?

I wouldn’t disconnect the battery, modern vehicles wipe certain aspects of the program like mileage trip/mpg data etc and can cause more issues than it’s worth. 

I would just leave it to be honest, a battery maintainer if you think it needs it. 
I used to leave my Saab for 3-5 months while at sea and never had a problem starting. That was without charging it or maintainers. 
if it’s just run once a week, I wouldn’t do anything. 
 

4 hours ago, frosty said:

yes, i have a C-tek charger on it. and it is usually garaged. 

I have a Yuasa (C-tek) charger, which works a treat

[V]

I am not convinced that maintenance chargers prolong the life of modern batteries that are not being used. I've got four maintenance chargers but I think wet batteries in particular need some movement while being charged to slosh the electrolyte.

 

I am not sure about maintenance chargers on AGM batteries. I think it may be better to leave them completely disconnected after being fully charged as they have very low internal resistance. Some can retain a full charge for as much as 2 years disconnected. The yellow top in my daily driven 2007 JKU was fine when the Jeep was sold when it was 3-years old. My Odysseys could go through months disconnected over a harsh winter and start first time in spring.

 

I have also wondered if off road driving is too harsh for a conventional wet battery. Perhaps the enhanced vibration and shock protection of a marine battery is better suited to an off road vehicle. I have asked Exide technical support a few questions today and I will report back when I get the answers.

 

Both of my Jeeps have IOD fuses. The user manual recommends IOD removal when not using the vehicle for a long time. This is easier than getting tools out to disconnect the battery but has the same outcome. XJ Cherokees, particularly the first gen models before OBD2 don't have much to worry about when disconnecting the battery. 

[Lee5euk]

I've just replaced my JK battery like for like.

Turns out the old one was 10 years old ??!

[V]

1 hour ago, Lee5euk said:

I've just replaced my JK battery like for like.

Turns out the old one was 10 years old

That's really good for a battery lifetime.

[V]

I received some interesting technical information from Exide today. I asked for an expert opinion on which of the following batteries would be the best choice for my older XJ Cherokee. I said that under bonnet heat can be a problem on Cherokees particularly in hot weather. The batteries that I am considering are:

• EL600 - Starting, Lighting, Ignition (SLI) Enhanced Flooded Battery (EFB)
• EM1000 - SLI Absorbed Glass Mat (AGM)
• EP450 - Dual purpose SLI and devices AGM

Exide's recommendation for my application, a non-daily driven off road vehicle with electric winch was for the cheapest battery, the EL600 as they thought the other two would have a shorter life expectancy due to the under bonnet heat.

 

They didn't send me any specific technical info for the batteries listed above but they did send some very interesting info regarding calcium wet batteries and AGM batteries concerning charge rates, voltages, temperature and storage.

 

The most efficient charging temperature range for 12V car batteries wet or AGM is 15-30 DegC. Wet batteries will experience damage that affects the battery life expectancy if charged in an environment over 50 DegC, for AGM batteries it is 45 DegC. This may explain why I have been unlucky with short lived AGM batteries in that Cherokee and have had better results with wet batteries.

 

Reading between the lines using the charge rate and temperature info provided, I think Exide agree with me about maintenance chargers. Their advice is to remove the battery from the vehicle and store it after being fully charged, indoors in a cool dry place with a temperature not exceeding 25 DegC. The battery should be top-up charged to a fully charged state every six months. For every 10 DegC over the C20 rate, the time between top-up recharges while in storage halves! If a battery is stored in a garage over summer and the temperature in the garage reaches 30 DegC, the top-up time limit drops to 3 months. If the temperature reaches 40 DegC the time limit drops to 6 weeks, 50 degrees it's 3 weeks. Higher than 50 degrees and the battery is being damaged just sitting in there.

 

I have often recharged my batteries in the Jeep parked outside in cold weather less than 15 DegC. If the temperature is lower than 15 DegC I now know that I should remove the battery and recharge it in a warmer well ventilated place. Likewise, in summer, if the temperature is over 30 DegC, recharge when it is cooler at night or remove the battery to recharge it in a cooler well ventilated place.

 

So, it appears that my XJ engine bay is hostile to batteries. I remember that the Mopar battery that lasted 14 years had a special plastic jacket that I now know was a heat shield. I should not have discarded it with the battery all those years ago as they are a bit on the pricey side now.

 

I have to make new battery cables for the EL600 as the terminal layout is reversed. I am going to make a heat shield for the 027 battery size and test it's effectiveness by installing a dual K-type thermocouple data logger to monitor the temperature at the battery case behind the heat shield and in front of it to see how effective different materials are for shielding.

 

If I cannot get the under bonnet temperature down below 50 DegC then I may have to relocate the battery out of the engine bay and switch to AGM. I am going to think this over for a few days before ordering a new battery. Relocating the battery to the cargo area would be a quick win but I lose cargo space and then have to run fused 650 Amp cables to the front of the Jeep.

Edited March 10 by V

[frosty]

very interesting article Vince, and i do note that my JK has a "heat" shield around the battery, i would imagine it is to keep it cool when running, and also to keep the frost off it at cooler temperatures. 

[V]

The datasheet for Optima BlueTop DC42 which is the nearest equivalent to the Exide EP450 states that the battery temperature must not exceed 50 DegC and the recommended charging rates specified are at 25 DegC. They don't state an optimal temperature range for charging but I doubt if the physics are any different. The 15-30 DegC range that Exide specifies may be a practical working temperature for recharging any lead based battery.

 

One thing that perplexes me is that vehicles are used in all temperatures and commonly tested to be suitable for use in environments ranging from -40/+40 degrees C. Assuming that an alternator will start charging a battery immediately after engine start, if the ambient temperature is not within 15-30 degrees C then are we always damaging our batteries using them in winter and on the hottest days in summer? I think we are, but until battery thermal management became a thing on EVs, few were aware of the problem. My guess is that the car manufacturers decided that the cost and complexity of replacing a battery was less than adding a temperature controlled battery heating and cooling system for a single battery. It certainly helps explain why OEM AGM batteries are in the cabin or in the boot.

 

 

[V]

I have just had a thought. I have had one of my Jeeps plugged into a maintenance charger for all of last week with overnight temperatures dropping down to freezing. I wonder if the charge cycle came on when it was cold?

 

My Accumate chargers have a separate temperature sensor to adjust the charge rate but I know they don't disable charging below zero as I have used them at minus twenty before. That probably explains why that Odyssey battery didn't last as long as I had hoped.

 

Looking for a lead acid battery management system (BMS) that measures battery temperature and thermal runaway...

Huasa H3G-TSX

[V]

It looks like vehicles with stop-start already have to monitor the state of charge of a battery and have equipment nicely packaged for this purpose. I found this one for a 2015 Ford F150 and I assume it outputs CAN bus messages.

 

 

[V]

This earlier one for a 2011 Ford F150 just measures current on the battery lead. I can see that being useful for an electric winch.

[V]

I have ordered the Exide 027EFB EL600 battery today. I am looking for technical info on the Ford F150 battery current sensors. I think they are either CAN or LIN. I am looking for modern alternator info specific to controlling charge rates. My current alternator is 90Amp with field winding control. I can upgrade it to an equivalent 136Amp or 160Amp but I am thinking if I make a dedicated CAN bus based battery management system for my Jeep I could precisely control battery charging with a bus controlled alternator. It also makes a split charge system for a rear mounted AGM with it's own current and temperature sensors a minor enhancement.

[stewart]

check out these guys https://www.redarc.com.au/faq-explaining-rbus-systems  not cheap gear !