In the last 3 weeks I've had to boost the batteries 3 times to get the Pajero to start (after 2 days at minus 20 or so). No block heater. Starts right away when it's warm of course. I get about 3 or 4 attempts of 15 to 25 seconds before it dies. While i'll be installing a battery warmer it looks like it may be time to replace the batteries . I have no history on the existing ones, one has japanese writing, the other north american.

So what type should I be getting- one with the highest cold starting amps I can fit in the tray, or
what? closed/sealed cell vs the type with caps? Some catalogs list the batteries by vehicle type, but I don't know if this has to do with physical dimensions or other electrical characteristics.

Should I replace both at the same time?

What brands are recommended and to be avoided?

Pros and cons of a deep cycle battery? They were recommended back when I had a 8K# Warn winch on a Bronco in the 80s?

Again, grateful for any advice.

Only 3 starts sounds like it's definitely time to change the batteries.

Best advice: Replace both - one weak battery can drag down a good one. Fit the largest and highest CCA ones that will fit.

Optima or other expensive AGM/sealed batteries are nice if you can afford it (I had a red top in my YJ), but not necessary unless you are doing steep climbs and they are spilling. Just buy a good name brand with a good warranty that you can get locally. I got mine (Energizer Max) at WalMart because of a good warranty and WalMarts are everywhere and open late.

From what I hear deep cycles batteries in a car aren't supposed to fully charge and require a trickle now and then. They also don't deliver the current a good starting battery will (more important in the cold.) A deep cycle is meant for long, slow drains. IMHO, a deep cycle isn't needed in an automotive starting/winching rig that already has dual batteries.

I agree, Optima batteries are probably the way to go if you can afford them. I ahve had good luck with interstate batteries as well. My Pajero came with Panasonic but not sure if they are the originals. They seem to have plenty of CCAs for the winter. Most important is the max number of cold cranking amps that you can put in though. If your Pajero is like mine, it hates you when it's cold.

Thanks guys. <img src="/forums/images/graemlins/smile.gif" alt="" /> Lots of Interstate dealers but can't seem to find any Canadian Optima dealers at least on the Optima web site. Will stop by Wally world and see what they have (once the Christmas/boxing day madness is over <img src="/forums/images/graemlins/lol.gif" alt="" />)

Costco and WalMart both carry Optima.

For what it's worth, I have learned my lesson regarding batteries. I will only ever buy batteries from a battery shop. I had 3 Canadian Tire batteries all die within 1 year: never again.
I was told about a shop called Davidson Battery in Vancouver, so I went there to get batteries for my trailer which is parked in the bush by 100 Mile House. They have been awesome! When the batts in my Chevy diesel died, I went to Phil's Batteries in Surrey and got 2 Northern Energys. Tons of crank, great service.
If you have a battery shop in your area, you owe it to yourself to go compare. They know everything about batteries and can answer questions definitively instead of WalMart boy guessing what you want to hear.

yes same here...I used a Battery Direct Gold plus battery in my old ram 50 for years and it was perfect. cheap too!!!

Both my batteries packed it in during the current cold snap at -40c in saskatoon. I bought two Platinum 24C 1000 CCA (Battery Direct LTD Part# P2484) they fit exactly as the original. I have used the platinums in three other vehs and I love them. They are pricy but they have a five year replacement plan. I put the new batteries in last night and this morning when i started my truck the difference was incredible. The same was noticed at work after sitting for eight hours at -38C with a oil pan heater.