What Capacity Battery for the Easy Eight?

[Andy Walker]

I'm looking at various batteries for my Easy Eight and have decided on a LifePO4 battery. I have found one that I'm thinking of using ( x 2 )and wondered if it would be suitable capacity wise?

Nominal voltage 12.8v
Nominal Capacity 24ah
Max discharge Current 24 Amp
Pulse 60 Amps <3 seconds

[Andy Walker]

Any ideas?

[Chris Hall]

Sorry, Andy - missed this first time around .........

Others know a lot more about LiFePO4 batteries than I do ! I've been following their advice, and have pretty well my entire fleet converted from Lead Acid now. But, from my experience:

1x 24v battery is much better that 2x 12v. You don't have to charge the batteries seperately, and you don't confuse the BMS in each battery. Size-wise, a 24v battery is usually the same as 2x 12v's, possibly even smaller and lighter.

As for Amps, my Mark IV will run all day on a 20A battery. My Centurion and Panther both run on 30A, which is probably overkill but will last a whole weekend without recharging. I've not actually seen an Easy Eight running, but I'd imagine anything in the 20-30A range would be fine.

Hope this helps,

Chris

[Adrian Harris]

I'm afraid I'm going to contradict Chris and say that two 12V batteries are barely heavier and are easier to locate in a tank than one 24V block.

And I've not had any problem with charging in series confusing either the chargers or the BMS's.

My first LiFePO4 battery was from an e-bike shop, made up of eight cells and rated at 15Ah at 24V. That would run my T-34 all day on grass, and the BMS only kicked in twice, over several years running, due to me having fully discharged the battery at a show. That pack was rated at 45A continuous and 150A pulse current.

I have recently acquired a running Easy8 but haven't wired it up with telemetry, so don't yet know what current it requires. Mine came with 2 x Yuasa 22Ah AGM batteries, so I'll keep them in there until they run out of puff.

The smoker takes 2A, the sound around 4-5A depending on the volume, so you have 17 or 18 amps for everything else. Even though the Easy8 has smooth tracks, I think you might struggle with only 24A continuous current supply, especially turning on longer grass. I'm just building up some packs with nominal 20Ah capacity and am fitting 40A continuous rated BMS boards.

Adrian.

[Andy Walker]

Thanks for the info. Its the constant and peak amps I'm concerned about. Maybe I'll have to keep looking...its a shame Tracer batteries are so expensive.

[Gerhard Michel]

Knowing that LiFes can usually stand much more than 40 amps continuous current I would choose 60 amps continuous current or more (may be 150 to 200 amps peak current). In our models a BMS is only necessary to avoid deep discharge or overcharging, but no current limitations. An automatic fuse is much better to stop high currents, because it can simply be switched on again without using a second battery or a charger 'in field operation'.

[Andy Walker]

I've finally taken the plunge and purchased 2 x LifePo4 Batteries ( 12 v /20ah ) . These have M5 bolt terminal connections. Does anybody know what size/capacity wire I need to use to connect the batteries in series, and also a supplier of suitable ready made battery connectors?

[Adrian Harris]

I'm using 10AWG silicone cable from the batteries. I don't know of anyone who sells ready made leads.

I make up short leads with ring terminals soldered to one end and XT150 to the other, so the batteries can be just unplugged from each other and the tank.

Adrian.

[Andy Walker]

okay, thanks Adrian. I'll search to see if any are sold ready made otherwise I will have to get soldering kit out. Do you think XT 60 connectors would be okay to use?

[Derek Attree]

Hi Andy
XT 60 are the standard connectors for the red modules
so at some point you will have to have one to plug into the red box .

Regards Derek

[Adrian Harris]

XT60 should be fine for general trundling around.

I've gone for XT90 and XT150 as I do my own wiring in most of the tanks. The XT150 are single connectors, so one for each battery terminal and the XT90 makes it easy to install the FrSky FAS100 current/voltage monitoring unit as it comes supplied with them.

Adrian.