Batteries not for trolling motors

[Lovey80]

[QUOTE=Monza;1703863]

Exactly. The supercapacitors will only give 5-10 good crank attempts until they are depleted. The main battery may then need to take a minute or two to recharge the caps. If using (for example) a winch continuously, once the caps are depleted, power falls back to the lithium battery component (25AH capacity, 60A max power draw) which may not be enough to run a large device. That’s why I run a seperate house battery for other accessories like winches, with a DC DC charger between them.

My main reason for the lithium/super cap battery was battery life (sick of replacing heavy lead batteries every few years), weight (30kg vs 7.5kg) and cranking power (fast cranking = quicker starts)

i looked at this option. How are you with regards to a BMS or if without one, limiting the start battery with regards to voltage once it’s full?

[Monza]

[QUOTE=Lovey80;1703864]

i looked at this option. How are you with regards to a BMS or if without one, limiting the start battery with regards to voltage once it’s full?

The FPV lithium/supercap battery comes with its own BMS to prevent over/under charge. But to protect it further I use a 14.5V DC DC charger from the house battery rather than connect it directly to the alternator (although the website say this will be ok).

You can apparently use the supercaps by themselves without an integrated battery (no BMS required as supercaps are virtually indestructible) but you will need a balancer. And probably a big fuse (1900A short circuit could be hazardous). And maybe a DC DC charger if you want more control over charging instead of direct off engine. You can buy the parts individually fairly cheaply from the website.

But I didn’t want to experiment too much, hence the integrated battery solution for me.

[Lovey80]

[QUOTE=Monza;1703865]

The FPV lithium/supercap battery comes with its own BMS to prevent over/under charge. But to protect it further I use a 14.5V DC DC charger from the house battery rather than connect it directly to the alternator (although the website say this will be ok).

You can apparently use the supercaps by themselves without an integrated battery (no BMS required as supercaps are virtually indestructible) but you will need a balancer. And probably a big fuse (1900A short circuit could be hazardous). And maybe a DC DC charger if you want more control over charging instead of direct off engine. You can buy the parts individually fairly cheaply from the website.

But I didn’t want to experiment too much, hence the integrated battery solution for me.

wait, isn’t this super cap hybrid used as a starting battery?

[chris69]

The super capacitor has its own bms ,if you want to build your own the bms for the 6 super cap cells is only $20,that FPV site has a lot of short vids to explain things were there coming from and how to use them in all sorts of areas.

[Monza]

[QUOTE=Lovey80;1703866]

wait, isn’t this super cap hybrid used as a starting battery?

yep. The hybrid (lithium+supercaps) is designed and use as a starting battery. The supercaps are recharged by the lithium if there is no charging current available.

But you can buy the supercaps by themselves to use as a starter battery with the $20 balancer (not really a bms, but similar in that it balances charge between the cap cells, but doesn’t manage over current, over voltage or under voltage - because the caps can handle 0-16V and charge/discharge at 1900A you don’t really need to manage this).

FPV don’t recommended the supercaps by themselves because you’ll only get 1/2 dozen cranks out of a charge (if the engine doesn’t start), and the caps self discharge over time.

[NAGG]

Cock it up .... pay the consequences.

it all sounds nice & easy ...... but if you dont know 100% what you are doing ....... dont

Chris