A quick battery question mate – I have a three-battery setup; N70 starting battery, with two deep cycle auxiliary batteries (105A/H, and 60A/H).
My 105 is starting to smell badly of rotten eggs and I’m wondering if it’s on its way out. I haven’t bought an under bonnet battery for a while, just thought I would check what else may be out there.
It does sound like your battery is on the way out. I would be changing it. There are a few new batteries out on the market now but before purchasing a battery there are a few other things to check as well.
If it is a lead acid battery then the new battery you purchase should be also a lead acid as the charging systems work on different profiles so it’s best to keep them the same.
Also, the charging system needs to be set to the correct charging profile. If it is a Redarc then if you change battery types this will need to be reset to the correct profile.
If the 60A/H battery is still good then just go the Century N70T, it’s a deep cycle lead acid battery that is perfect for use under the bonnet.
If you want to change to an AGM battery, the Optima is also OK under the bonnet. I have checked this a few times with them and they will have a smaller size. Century have also released an AGM Dual Force battery but they don’t have a smaller battery to couple it up, with so you may need to use an Optima as the 60AH battery. You will also have to change the charging profile to suit the AGM setting.
One other thing to think of is that most battery brackets have a recommended weight, so remember that if swapping to a heavier AGM battery.
Hope that helps