Comments about your Lithium Battery

[Pat911]

As Volt_Ampare already stated above, discharging below freezing will only affect performance and is not detrimental to the battery. Charging below freezing is.

I don’t know of any battery that will keep itself warm whilst off charge.

If you DIY your pack then you could possibly use the heating pads to also keep the batteries warm whilst off charge to maintain performance, switchable of course, but how long you could do that for will be determined by the factors described above. If you DIY you could always up the cell size to allow for it though.

[Volt_Ampere]

Cold is not an issue here in Arizona. :-) I used to fly electric model planes in Colorado in the winter and we had performance issues with Lipos. The trick was to keep them warm before flying and to wrap them in foam so that they stayed warm during flight. Not so easy with a cart if you have to keep it out in the cold. I don't intend to ever experience cold again though.

[DaveTM]

FLA’s won’t freeze while sitting outside in sub freezing cold. The energy in the battery prevents the water from freezing.

I can’t speak with 100% certainly that lithium’s won’t freeze…but I gotta think with all that stored energy, freezing isn’t an issue. But…I don’t know that for a fact.

[Pat911]

It’s not about freezing per se Dave, it’s about operating at below freezing temperatures. Lithium batteries cannot be recharged when they are below 0 degrees Celsius (32 Fahrenheit) without serious irreversible damage. They can be discharged below 0 Celsius but performance drops off dramatically.

[Volt_Ampere]

FLA's don't freeze at normal freezing temps if they are charged because the liquid isn't water at that point. If you discharge them, then they will freeze and crack the cases. It's not the stored energy - it's the composition of the liquid.

[pfleef]

Let me ask what might be a dumb question. But I am really having a hard time finding information on this.

For lithium packs in general (and all the ones reviewed here), do they have a lower peak discharge rate (temporary and long term) than a standard six-8v set of lead acid? If so, does that show up in any performance loss?

I have a lead acid set I need to replace in my precedent, and I love the start speed, power and top end speed using my Alltrax 600A controller. Don't want to give that up if I switch to lithium. Thanks in advance.

[Tom47]

There will be a measurable increase in performance partially due to the nearly 300# less weight.

I have heard no complaints about any loss in performance going from FLA to lithium. I should have made that one of my questions on this thread.

Here is an interesting read explaining FLA vs LFP batteries:

https://www.power-sonic.com/blog/lit...cid-batteries/

[Volt_Ampere]

True as long as your Lithium pack has a reasonable spec for discharge rate. There are two specs - one for continuous and one for peak for ?? seconds. The BMS will protect against this by shutting the system down. The BMS can't limit the discharge current.

[Tom47]

Originally Posted by Volt_Ampere

True as long as your Lithium pack has a reasonable spec for discharge rate. There are two specs - one for continuous and one for peak for ?? seconds. The BMS will protect against this by shutting the system down. The BMS can't limit the discharge current.

That is very true! I would be concerned if I had a non-user adjustable high amperage controller.

The Alltrax allows me to throttle operations down to a satisfactory level for me and the battery.

BTW, see the battery comparison link I added in the post above. It has some good general details.

[pfleef]

Thanks for the quick response. A lot of the lithium packs I see are rated for 100A continuous and 200A for 10 seconds or so. Anyone know the rating for a set of six 8v’s? I feel like it would be significantly higher but can’t find those specs anywhere.