Let's talk batteries.

[smritte]

Could you direct me to some weeds to get into? I was really considering an AGM. There is one AGM that I know works with a factory setup, but I don't know if it would be good for what I want to setup.

Bottom line on all batteries is charging voltage and temperature. If you research optimal "automotive" battery charging, you find its either based on old out dated info, modern info or propaganda to sell something, with most info based on a lab environment not what happens in a vehicle. The difference being new charging systems verses old, verses sales. Some places and people stick with old data because that's what they learned and that's what they stay with.

Some of the biggest issues were with AGM's. AGM's got a bad rap because early AGM's, really weren't happy on the older charging systems. Another issue you find in the data is no one can/will tell you exactly how much life you loose in a modern system with modern AGM's. I personally have run mixed AGM's in vehicles without a management system for decades and they still seem to meet or exceed factory projected lifespans.

I now only run Odyssey batteries and will never run Optima's. The reason is, 15 (ish) years ago they were bought out. The new company changed the design and you were lucky to get two - three years before they stopped working. They even hired a guy to hunt all the forums looking for complaints. His name was Optima Jim. He would basically tell you how the battery failure was your fault. If someone with proper knowledge popped in, he wouldn't comment on that thread again.
The quality was so poor, a few auto part stores stopped carrying them. The company was forced to redesign the battery to what we see today which, I'm lead to believe is the quality they used to have. Unfortunately some of the bad rep AGM's have was based on that fiasco. I went through three Optima's in three years (all were warrantied), four if you want to count the one in my wife's S-10 that quit working after about 2.5 years.

Lithium's on the other hand rock, but you really need to pay attention to charge rate and temperature. As much as I would like to switch to lithium's, the temperature range I camp in, I cant run them.

 

[rsweet]

So then my follow-up inquiry would be:
- Is a Yellowtop worth it or just get a strong Redtop?
- If a Redtop is enough, why not just another brand AGM?

I would think if I do end up getting a fridge and lights, I would want to figure out a second power setup for those. For the vehicle itself, I really just need a strong starter that can run basic accessories - dash cam that’s hardwired instead of 12v DC outlet and can run parking mode, new dual DIN head unit with screen. I can’t really think of anything else I’d run on the car battery. But I’m also very new to all this and have never been great with electrical, so I may not be planning accurately.

Yellow top all day long. Replaced my Toyota Tundra battery with yellow top...no issues ever since.

 

[CafeRoaster]

snip

Thanks! I have read that story about Optima, and I did originally start looking at Odyssey. Maybe I'll just go back to them. Optima has a lot of sizes though. But I think I found one that'll work in mine. I have a 35 group right now, and I think the 34 group Odyssey would fit perfectly.

I don't *anticipate* my demand will be much, but it would be nice to be able to run the inflator off the battery without running the car - my current battery was drained by parking mode on my dash cam.

 

[Shakes355]

Great stuff there from smritte. I will add that use plays a large role as well.

If an AGM is used in place of an FLA (flooded lead acid) as a primary starting battery and the owner has reasonable mechanical sympathies (i.e: the vehicle is run regularly or has a maintainer installed, doors and lights aren't being left open/on, etc), then there is a good to great chance (depending on battery quality) that it will match or outlast the factory unit.

If, on the other hand, the system sees abuse (i.e: is only ever started every couple of weeks and/or rarely driven, the starting battery is used to handle "house" duties such as appliances and exterior lights and is otherwise regularly discharged below 70ish%), without precautions that battery has a much higher chance of premature failure.

Sure, a non-deep cycle FLA has only a handful of full discharges before it starts losing capacity, but dead AGMs can trick a voltage regulator into reducing the amperage the alternator makes available. In fact, a fully dead AGM that has been jump started may not charge at all in a traditional system and would not have absorbed enough juice to start the vehicle again after significant run time. Undercharging an AGM repeatedly will absolutely reduce it's lifespan.

The drawbacks are lessened in a dual-battery system due to the nature of voltage equalizing. Where if a fully charged battery and a discharged battery of equal capacity are connected in parallel without a charger, one will in essence charge the other until both are half charged. The primary battery will simultaneously allow amperage to flow to the dead secondary battery while also keeping the voltage stable enough for the regulator to provide the proper output.

The same trick works for charging a dead AGM with a traditional charger. Connect the AGM to a regular FLA and charge the FLA. After an hour or so you can remove the FLA and charge the AGM directly on low until it is finished.

Obviously there's some deeper stuff going on, but I hope this helps.

 

[smritte]

The drawbacks are lessened in a dual-battery system due to the nature of voltage equalizing. Where if a fully charged battery and a discharged battery of equal capacity are connected in parallel without a charger, one will in essence charge the other until both are half charged. The primary battery will simultaneously allow amperage to flow to the dead secondary battery while also keeping the voltage stable enough for the regulator to provide the proper output.

Absolutely true.

All this talk about properly charging batteries as well as the amount of time it actually takes to charge a battery brings up a point. "IF" you have a bank of batteries (2+), camping until their down some (40%), can you use your charging system to attempt to "fully" recover that bank by driving?

The answer is probably not. This is assuming you have a system built to bring them all the way up. There are too many variables involved without doing the math individually. Lets not even think about the "start/stop" technology in a heavy traffic situation.

I run a total of four with my trailer and most of my camping is done within three hours of my house. Even with my vehicle batteries kept up by not leaving it parked the whole time (second fridge in it), I still wont bring my trailer batteries back to even close to full. This is AGM and (or) lead acid.

My personal answer is, the trailer has a smart charger built in. It gets plugged in when it gets home. Both have their own solar with charge controllers to help supplement my mix of AGM and Lead Acid when they sit at home. If parked long enough, my solar is large enough to cover the amount I use "IF" its not cloudy.

What's interesting here is modern charging systems (2000+) are more than capable of being smart chargers (vehicle only). Why don't they do it? If your computer is controlling the alternator, most of the work is already done. The answer (in my opinion)is your not suppose to replace the battery with something other than what It came with so why add in a small, cheap circuit to do this.
If you add in more batteries, they would self regulate (as long as they were the same). Too many would stress the alternator.

If the factory ran an AGM, they would bump the alternator voltage up .2v. When the battery finally wore out, odd's are the owner will go cheap and replace it with a lead acid. Now the charging voltage it too high giving it a potential for overcharging. A "smart" alternator would compensate. For several hundred dollars, you can make your system a smart charging system. If you understand how all this works and you understand how to test things, you can save yourself a bunch of money by not needing to run a management system. Unfortunately, you loose the cool factor.

Bottom line here is, if your going to modify or add to your vehicle beyond what it came with from the factory, learn how that system functions (including the mods), before you depend on other peoples technology to make things better. If you learned it years ago, you need to relearn because the technology evolves about every 5 years. This is especially true if you have someone else mod your system. Just because their a "professional" install shop, does not mean they know how to diagnose it or how it actually works. You would be surprised (or horrified) what I have to deal with on a regular basis.

One warning though, Ignorance is actually BLISS. The more you learn the more you realize that most of the "Experts" were just giving an opinion based on out dated information not fact (or total BS for some reason). OH......that also means U-Tube will start to scare you.

 

[CafeRoaster]

Really enjoying the conversation here.

Last night, I replaced my battery in an attempt to fix an issue with my vehicle not starting. I was stuck after picking up two six packs (worse could happen). I discovered that it was just a connection issue - my positive terminal's connector requires a large amount of tightening. I'll replace it at some point but for now it's fine. So, now I have two batteries. Now I have options.

I could run a two battery setup instead of getting a Jackery or similar. Here are the batteries I have:

Installed
Super Start Platinum SSB 34PLT AGM (brand new)
750 CCA
120 min reserve

Uninstalled
EverStart Maxx 35N Lead Acid (was new in July 2021)
640 CCA

I'll have to get a tender for the battery that's now uninstalled. Also, I'll need to learn about dual battery setups, and decide if I actually want or need one. I don't know how deep I want to get into overlanding, or even how much power I'll need. I can't foresee wanting much power except to charge camp lights, devices, etc. I honestly don't know what the heck folks need so much power for. Maybe light bars? I really haven't researched it a ton.

Since I'm in a Honda Element, I don't think I'll be rock crawling or doing anything requiring a ton of clearance. My lowest point is 10.5 inches.

If y'all could steer me toward some good resources for where I'm at, I'd be super appreciative.

Thanks!

 

[astroflashjones]

Really enjoying the conversation here.

Last night, I replaced my battery in an attempt to fix an issue with my vehicle not starting. I was stuck after picking up two six packs (worse could happen). I discovered that it was just a connection issue - my positive terminal's connector requires a large amount of tightening. I'll replace it at some point but for now it's fine. So, now I have two batteries. Now I have options.

I could run a two battery setup instead of getting a Jackery or similar. Here are the batteries I have:

Installed
Super Start Platinum SSB 34PLT AGM (brand new)
750 CCA
120 min reserve

Uninstalled
EverStart Maxx 35N Lead Acid (was new in July 2021)
640 CCA

I'll have to get a tender for the battery that's now uninstalled. Also, I'll need to learn about dual battery setups, and decide if I actually want or need one. I don't know how deep I want to get into overlanding, or even how much power I'll need. I can't foresee wanting much power except to charge camp lights, devices, etc. I honestly don't know what the heck folks need so much power for. Maybe light bars? I really haven't researched it a ton.

Since I'm in a Honda Element, I don't think I'll be rock crawling or doing anything requiring a ton of clearance. My lowest point is 10.5 inches.

If y'all could steer me toward some good resources for where I'm at, I'd be super appreciative.

Thanks!

Honestly, the simpler you can keep your electrical system the better. The more complicated the system, the more room there is for error. I held out for a long time before adding a second battery but I do a lot of solo travel with my wide and two year old. We run a fridge, diesel heater, and charge stuff. We also stay in place for more than a day sometimes, so the starting battery gets juiced. Last thing I want is to get stuck in the middle of nowhere by ourselves. If youre just charging a few devices at camp theres really no need to worry. Even an efficient fridge can run off a good AGM starting battery.

 

[leeloo]

there are 2 things that kill AGM's quick - heat and deep discharge below 50%. You avoid those and even a medium price quality one will serve you as an aux. battery for a long time, I am talking 5 + years.
Right now, for any aux battery system you need a dedicated DC to DC. I had 100 amp AGM that I was running straight from the alternator, it was barely enough to keep a fridge running and charge a phone a tablet...It was never full. Once I got a dc to dc charger never went below 75 % .
Lithium is now more affordable, and where space and payload is at premium, it is worth it.
If you are sure you won't need to scale up and add induction cooking, hair dryers, expresso machines, or what ever glamping things you want to have right now the easiest as a DIY and same cost as dc to dc + lithium is power station, like eco flow or Jackery..
If you don't haver the skills and tools to DIY a dc to dc + agm or lithium and you need to pay someone for the install job, than financially a powerstation wins hands down.

 

[Viking1204]

My second battery that runs my fridge and other items is a 138ah Lithium battery. I've installed a 100ah solar panel on the roof of my truck and a Redarc DC to DC charger and can now run my fridge pretty much indefinitely if I just drive or idle my truck for a short time every 3 days. I bought a slightly used battery off Ebay for a discounted price and it has now been running my fridge for 2 + years without any decrease in performance. Lithium is the way to go if you can afford, unlike most items Lithium batteries seem to still be dropping in price.

 

[Shakes355]

My travels don't include a lot of the "standard" overland gear. By that I mean, I'm not running solar, fridge, etc. Heck, I'm not even into RTT's. But I have found a second battery useful for many things, including peace of mind that if my primary does die (mistakes do happen), I have another.

I personally have an Amazon-special battery isolator kit. It meets my needs just fine and has served me for a few years now without issue.

KeyLine Chargers 12V 140 Amp Dual Battery Isolator Voltage Sensitive Relay (VSR) Pro Dual Battery Kit

 

[CafeRoaster]

I need to figure out what to do with my previous battery that's still good. Hah!

Any ideas? I really think the most I would ever run is a fridge, but that's so far into the future that it may not even happen.