if its electric motors you need correct voltage and be able to supply the amps it wants, which is massively dependent on speed of rotation and the torque it needs to produce. power supply might trip out.... your fan or wiper motor can suck 30+ amps at 12-14 Volts for few milliseconds before it settles down to something like 7amps when turning at speed.
car electrics are horrible, and the DC is more like the crenellated battlements of a castle so your power supply is potentially Luxury.
provided it can get over the start pulse ,i would think the gearing and hence torque necessary would be limited to using a current befitting of a 1970s car i.e less than 30 amps and potentially by quite a long way .
should work.....
but if it doesn't
Run two in parallel
OR
Lithium based battery tech can be stored for months/years at a time at storage voltage of 3.7 V top em up to 3.7 and leave
charge to 4.2 and use straight away they will fall to 3.7 V and stay there for 80% of the useful time then fall to 3 .?? time to charge. 3.7 for storage 4.2 for use
so i will recommend 3 or 4 of the batteries that i have put a link to below, strapped together with bus bars in serial config or double up and do 4 serial 2 parallel for more amp hours.
3.7 (4.2) volt lithium ion battery designed to power a detroit electric "super car" when used in bulk
nominally 3.7 volt, fully charged at 4.2 but charge em up to 4 or 4.1 and they can last years
3 or 4 in series gives you any where between 14 and 16.8 volts which is fine car stuff should survive a little over voltage 14.2 is what car stuff expects when the alternator is ON at full chat.
its a 20 amp hour battery with a maximum discharge SPIKE of 10C or 10 times capacity i,e 200 amps and the can sustain 5C or 100 amps continuous for 12 minutes
i have 10 of them. as i'm building a dangerous push scooter, of a type that isn't banned at santa pod, because my less dangerous 20 cc petrol engines one is banned,
and i also have the burnt finger to prove it...
https://www.ebay.co.uk/itm/72v-20ah-diy ... SwbFFe1BzL
speak to jimbob, phone number usually in one of the pictures on his listings, he doesn't like paying e-bay, you can pay pal but cash in hand works as well..
expect to pay £11-£12.00 each and £10 of copper bus bars (5).
you will need 4 x12 mm long m4 button cap + spring washers to bolt on bus bars. use the extra one cut in half for + and - connection.
he uses these to power his barge.... hes an electric vehicle designer of the itinerant kind
build battery pack, m6 stud at top through cases, cable ties at bottom
THEN ZaP STUFF
use a lipo charger for 4 serial cells or invest in a laboratory power supply to charge at 3 amps and about 16 volts
I can recommend a Gophert supply for charging LIPO and lithium ion batteries, provided you know what you are doing, its way better than the standard black box chargers.
I have
GOPHERT NPS-1602 0-60V 0-3A 110V/220V 180W Switching Digital Adjustable DC Power Supply very precise clean power supply)
and i use it to charge my 42 volt 10s set of these batteries
they stay in balance so no need for BMS
or you can get some from his mate in Manchester, at £12.30 each
just type EIG cells in eBay
made in Korea not china, and Koreans do not seem to lie about battery spec
as long as you don't discharge them down to less than 3 volts each regularly (12 volt for the pack) the pack will last a very very long time
please charge outside.........! burning lithium makes a right old mess of you and your belongings
also handy when camping or for powering led Christmas lights
Dave
