LiIon batteries for our ATC's

[big specht]

We just had this discussion in the shop last weekend and I remembered reading a thread on here about drill battery’s. So from what I read the stock charging system doesn’t put out the right voltage to charge the lithium battery’s. What got us talking was we have spare drill battery’s.

[ps2fixer]

Take the 18v or the fake marketed "20v" battery apart and instead of 5 series (3.6 * 5 = normal 18v), make it 4 series (and whatever parallel for capacity) and you fix the voltage difference issue (3.6v * 4 = normal 14.4v, a car battery is 6 series of ~2.1v cells for 12.6v). The real problem is you cannot float charge a lithium ion battery, it must have a charge controller or "BMS" aka battery management system to keep each group within the proper voltage range, unless you like random fires starting.

There are proper 12v batteries made that are lithium ion based and include a BMS so it's a drop in option, they aren't cheap, but they do give a massive benefit of less weight, very very compact, and can be mounted at any direction.

This random page shows the lithium ion cells with the circuit board (BMS). The 7ah would be great for something that doesn't have electric start, just for lighting. 12ah+ would be more ideal for machines with a starter. The real spec is the max amps, but you'd want a good reserve and not to stress the cells too hard per start. The 12ah is rated at 120amp peak for 5 secs, a 250es probably draws around that, maybe a bit more. The continuous amp draw spec is 12a (or 1c in battery talk), which isn't huge, but for most 3 wheelers that's fine. Atv's with a cooling fan and lights can blast through that 12amp max spec pretty fast. Of course with the machine running, most of the power should be coming from the engine, but key on fan running + aftermarket lights + stock lights on isn't too uncommon use case.

Lithium ion is for sure getting to be more in the price range of being used in more applications now. They were like $300-400 last I looked for an atv sized battery, $150 or so is something like 2-2.5x the price of a normal lead acid battery (AGM is generally best for atv's). A car sized battery (750amp peak is similar to a 650-750CCA battery I'd think) is still $950, a cheap car battery runs around $100-120ish and a more name brand can hit $150-200ish, so the larger options are kind of expensive yet. Only one website though, another brand might be cheaper and perform similarly.

https://www.lithiumion-batteries.com/

[big specht]

Ok I understand we were just dreaming with all the bikes we have that take battery’s. It would have been nice to be able to switch out battery’s easily.

[ATC King]

Shorai batteries are some of the least expensive. I've had one on a motorcycle for at least five years and no problems with it lacking a BMS. They do have a balance charging port for a specific charger as a maintenance procedure, but I've never used one on it.

One for the 200ES is ~$160 and they claim 15.07 lbs lighter than OE. Fifteen pounds is substantial and no worries about leaks when the rubber side is up, or any time. The AGM batteries for the 200ES tend to actually weight more than OE.

https://shoraipower.com/battery?type...43&year=380943

Antigravity doesn't list one for the 200ES on their site and it looks like they don't list any motorcycle/ATV battery prior to 1990 claiming that's before standard sizing. Like the Shorai though, a smaller battery can be used that has equal cranking power. The empty space is taken up by dense foam sheeting or blocks. The Antigraity batteries have a BMS, which isn't always needed and can have their own issues when built in to a product. Thy also have the Re-Start feature that won't let the battery discharge past a certain point and pressing a button allows for enough power to start the engine. They are much more costly than the Shorai though.

https://antigravitybatteries.com/

There's the other brands already mentioned in this thread too. Even Harley sells a HD branded lithium battery.

No need to make it complicated. There are quite a few choices and price ranges out there.


Here are the FAQ pages for Shorai and Antigravity:

https://shoraipower.com/faq

https://antigravitybatteries.com/hel...neral-batt-faq

[ps2fixer]

Interesting on the Shorai batteries with no BMS, I wonder what they do to get around the over charging issue and lithium ion batteries off gassing when over charged. Maybe there's new tech I'm not aware of, stuff has been moving fast in the battery world.

[ATC King]

As long as the charging system doesn't go over the accepted standard of 14.7V, the currently available lithium motorsport batteries should be fine. They're designed to be used on vehicles that originally had a FLA.

I'd have to look at the specifications Shorai provides, but unless the battery voltage falls below a certain threshold the BMS charger they sell isn't required to balance the cells. I've kept mine well above that.

I've tried pretty much all of the available battery technologies and other than the gel cells, the stuff available now is all viable in the right application. Just have to weight the pros and cons for each application. FLA batteries have that leaky problem that'll ruin paint and metal if not kept in check, so using something other than that on a vintage/classic machine is better. A vent hose on a battery is so last millennium. VRLAs and catalysts type battery systems solve a lot of the FLA problems, but have fallen to the wayside years ago despite their effectiveness. It's actually sad to see the lead battery go away, because it's much easier to maintain, service, and recycle.