Lithium Ion Batteries

[Vic Harder]

I went down the Lithium Route - with Starpopwer. I am happy, but it takes a lot of tuning and money. I would recomend upgrading the wiring from the truck first and see if it fixes your issues. That alone made a huge difference. Modern trucks don't put out a steady 14.4 Volts like in the old days, they can turn off completely to save power once the truck battery is charged. My GMC runs between 13.2 and 14.4 volts depending on the day.

I went with adding a second alternator with separate regulator for the camper. This way I could provide a consistent 14.4 volts (now reduced to 14.1) to the batteries. They charge at upto 60 amps when needed - over 4 gauge wires. Google your truck model to see if there is a second alternator kit available for it.

Did you use some kind of custom adjustable regulator?

 

[cdbrow1]

Did you use some kind of custom adjustable regulator?

Yes. I used a Balmar adjustable regulator. Very pricy - but rock solid.

 

[cdbrow1]

One major change with Lithium batteries is that they have very low resistance - they can charge much faster than lead acid. It is theoretically possible to damage your alternator (never heard of it actually happening). The Balmar alternator has a load controller that makes sure the alternator doesn't work too hard. It is NOT an issue if there lead acid batteries in the system since they provide the resistance needed.

 

[Vic Harder]

Yes. I used a Balmar adjustable regulator. Very pricy - but rock solid.

Ah yes. And one of their alternators too? Curious if you had to make a custom mount for it for your truck, as they seem to only supply mounts for the diesel/marine engines

 

[cdbrow1]

I got a dual alternator kit from Nations for my Duramax 6.6 - the Duramax is built for two so it's pretty easy to do. I just did not wire it into the factory wiring harness.

http://www.nationsstarteralternator.com/Multiple-Alternator-Kits-s/822.htm

They are very helpful via email and phone calls.

 

[Wallowa]

Not negating any of the thought provoking posts on "going Lithium"...but a sincere question: What is actually gained by going to two Lithium batteries in my Hawk as opposed to the current AGM batteries"? No real knowledge in this arena so be patient and "speak slowly" in listing the net gains.


Thanks,

Phil

 

[hebegebe]

I know weight is one good reason I changed my battery in the Ducati and it went from 12#to less than 2# with more power and less discharge. Amazing but spendy!


Sent from my iPhone using Wander The West

 

[rando]

The primary benefit is more capacity for less weight. For instance, a 100Ah LiFePO4 battery weighs ~30lbs. You can also safely use almost all of that capacity without prematurely aging the battery. If you were to follow the AGM 'rule of thumb' of only running your batteries down to 50% on a regular basis - that 100Ah LiFePO4 battery has equivalent capacity to 3 of the stock Exide 70 Ah AGM batteries, which would weigh something like 150lbs. So you get the same energy storage at ~ 1/5th the weight and 1/3rd the size.

There are some other minor benefits - the battery voltage is slightly higher (~13V) and doesn't significantly drop as the battery drains, so you are still getting 12.8V near full discharge. The internal resistance is also lower, so you can theoretically charge them faster if you have a high amp alternator. The lifetime is also theoretically longer - 2000 - 4000 charge cycles, although there is some evidence that this doesn't hold up so well under real world conditions. You also don't need to worry about not fully charging the battery between cycles - it is fine to run the battery down to 30% then only charge it back to 80% before running it down again.

Of course there are also drawbacks. They are much more expensive $900 for a plug and play 100Ah solution (Starkpower) or ~$600 for a DIY solution (4 CALB 100Ah cells). You also need to be a little more careful with charging and discharging. While the commercial versions have a built in Battery Monitoring System (BMS) which protects the battery from abuse, you still need to be aware of the slightly different requirements for care and feeding, particularly if you go the DIY route. Finally, what may be the biggest issue for using these batteries in a vehicle/camper - they shouldn't be charged in below freezing temperatures (<32F or 0C). Discharge at low T is fine, but charging could dramatically shorten the life of the battery. If you winter or shoulder season camp, this is something you need to be aware of and address.

Not negating any of the thought provoking posts on "going Lithium"...but a sincere question: What is actually gained by going to two Lithium batteries in my Hawk as opposed to the current AGM batteries"? No real knowledge in this arena so be patient and "speak slowly" in listing the net gains.


Thanks,

Phil

 

[Wallowa]

I know weight is one good reason I changed my battery in the Ducati and it went from 12#to less than 2# with more power and less discharge. Amazing but spendy!


Sent from my iPhone using Wander The West

Thanks.."GeBe"

Yup...my motorcycles all use AGMs to prevent acid spills when they fall over on the trail for a "nap" [almost 100% off-road]...Weight is an issue on the bikes but not really for us with the Tundra/Hawk.....

AGMs on my bikes are more vibration resistant than lead/acid; also a plus...are Li batteries also less prone to damage from jolts and vibrations?

Phil

 

[Wallowa]

The primary benefit is more capacity for less weight. For instance, a 100Ah LiFePO4 battery weighs ~30lbs. You can also safely use almost all of that capacity without prematurely aging the battery. If you were to follow the AGM 'rule of thumb' of only running your batteries down to 50% on a regular basis - that 100Ah LiFePO4 battery has equivalent capacity to 3 of the stock Exide 70 Ah AGM batteries, which would weigh something like 150lbs. So you get the same energy storage at ~ 1/5th the weight and 1/3rd the size.

There are some other minor benefits - the battery voltage is slightly higher (~13V) and doesn't significantly drop as the battery drains, so you are still getting 12.8V near full discharge. The internal resistance is also lower, so you can theoretically charge them faster if you have a high amp alternator. The lifetime is also theoretically longer - 2000 - 4000 charge cycles, although there is some evidence that this doesn't hold up so well under real world conditions. You also don't need to worry about not fully charging the battery between cycles - it is fine to run the battery down to 30% then only charge it back to 80% before running it down again.

Of course there are also drawbacks. They are much more expensive $900 for a plug and play 100Ah solution (Starkpower) or ~$600 for a DIY solution (4 CALB 100Ah cells). You also need to be a little more careful with charging and discharging. While the commercial versions have a built in Battery Monitoring System (BMS) which protects the battery from abuse, you still need to be aware of the slightly different requirements for care and feeding, particularly if you go the DIY route. Finally, what may be the biggest issue for using these batteries in a vehicle/camper - they shouldn't be charged in below freezing temperatures (<32F or 0C). Discharge at low T is fine, but charging could dramatically shorten the life of the battery. If you winter or shoulder season camp, this is something you need to be aware of and address.

Rando,

Thanks for a lucid dump of info; appreciated.

Cost vs benefit of course is always a consideration; but, having a reliable system for "off grid" use is #1 unless the costs become obscene/out of reach.

More capacity for less weight...I get that as stated in previous post.

With my solar [160 + 80w] and vehicle alternator the frequency or time required for recharging the AGMs vs the Li batteries is a moot point for us. Not being able to charge below 32F IS salient issue for certain.

We would never exceed the 50% draw down before recharging.

Dropping 100 lbs of weight [assuming two AGMs are about 160lbs] would be nice but again not critical.

All this balanced against the cost of batteries and other mods [mentioned in previous posts] needed to accommodate a Li system, makes for us switching batteries from AGM to Li batteries impractical.

But never say never; perhaps we will re-consider the need and review the Li application to resolve that need in the future.

Thanks again for the discussion and information.

Phil

 

[captainphx]

I replaced the wires from the factory from my truck battery all the way to the camper battery with 6 gauge wire with 60 amp fuses on each end.

Why 60 amp fuses on EACH end? Any particular kind of 6 gauge wire?

 

[craig333]

Hopefully the price comes down by the time I retire. The fast recharging is the big selling point for me. I can foresee a time when I'll maintain a camp for a week and being able to charge the batteries by solar only would be a big help then. For short periods of freezing weather it shouldn't be hard to keep them warm and I for one, don't plan on camping in freezing weather more than a short time

 

[PaulT]

Why 60 amp fuses on EACH end? Any particular kind of 6 gauge wire?

You need to protect the wire from shorts from current coming from either the truck battery or the camper batteries so add fuses or circuit breakers at each end.

Paul

 

[captainphx]

You need to protect the wire from shorts from current coming from either the truck battery or the camper batteries so add fuses or circuit breakers at each end.

Paul

So, a fuse in the positive wire and one in the neg?

 

[captainphx]

This is the breaker that is installed now. 10 gauge wire.

 

[PaulT]

So, a fuse in the positive wire and one in the neg?

The positive wire needs a fuse/circuit breaker in the camper and another under the hood. The reason is if the hot wire gets cut or otherwise damaged anywhere along its path, either the camper battery or the truck battery or both could dump 100's of amps into the wire to the short. In that case the wire gets very hot, potentially causing a fire and or sparks igniting flamable material under the truck or in the camper. Unlikely, bringing a good result.
The fuses protect the wire to give you a second chance to fix a problem.

Paul

 

[captainphx]

The positive wire needs a fuse/circuit breaker in the camper and another under the hood. The reason is if the hot wire gets cut or otherwise damaged anywhere along its path, either the camper battery or the truck battery or both could dump 100's of amps into the wire to the short. In that case the wire gets very hot, potentially causing a fire and or sparks igniting flamable material under the truck or in the camper. Unlikely, bringing a good result.
The fuses protect the wire to give you a second chance to fix a problem.

Paul

I am assuming you use stranded 6 gauge?

 

[DavidO]

Captainphx I wish it was just as simple as just throwing in a bigger wire. The 6 gauge wire that I used was from Lowes if I had to do it again I would use 6 gauge welding wire like this https://smile.amazon.com/TEMCo-WC0450-Welding-Battery-Copper/dp/B01JMNKYEC/ref=cm_cr_arp_d_product_top?ie=UTF8

You will need some kind of fuse or circuit breaker as close to the truck battery and as close to the camper batteries as possible. These will be on the positive side at both batteries. There is no need for a fuse on the negative side.

Captainphx I PM you please give me a call

 

[craig333]

Yeah, don't use cheap wire. I used 6ga amcor. I opted for this style of fuse because I'm running out places to mount stuff.

 

[DavidO]

Craig yours looks a lot like mine. https://www.delcity.net/store/Maxi-Fuse-Holders/p_11183.h_36724.t_1

shown with the cover off showing the Maxi Fuse.