1x24v or 2x12v battery’s and other related q’s

[Gary Richardson]

Hi Stephen

Thanks for the reply, I can confirm it will not fit under the turret area as I tried adding the turret ring and there is zero clearance even with the battery tray upside down to give an extra 5mm. I tried it in the engine compartment but I will have need to install the track adjusters and idler axles and again it looks very tight and may block access to the exhaust outlets as well.
Still, I must look on the bright side, I am making good progress on the Tiger and learning a lot, and its only 11 days until Tiger Day at Bovington

Regards

Gary

[Paul Sparkes]

Well I took the plunge and got the 24v 36ah battery. It is indeed huge, but I think I can make it work.
It won’t work with the stock recoil unless moved back a long way.

[Gary Richardson]

Hi All

While researching for a smaller 24v LiFePO4 battery than the Ultramax that Paul has acquired I came across the 12V 20Ah Powerbrick + that are available for about £200 each , the spec sheet looks very good for our needs: https://cdn.customfields.bonify.io/inte ... V-20AH.pdf
Instant peak discharge current 180±30 A (max 100mS)
Continuous discharge current 40 A (512 W)
Maximum discharge current (< 30s) 60 A (768 W)

The battery has a built in BMS and the size looks good at L : 180mm W : 76mm H : 168 mm and two can be linked to give 24v. They are considerably cheaper than Tracer batteries and look to have a higher spec. You do have to buy separate chargers.
They also do a 24V 36A LiFePO4 but it doesn't seem to be available here and they do not ship to the UK at present which is a shame as it is a lot smaller than the Ultramax equivalent.

I would run separate charging points from each battery so both could be charged at the same time.
My question is do you think two of these be a good choice for a Tiger using the new red option packs and is there any likely problem if one BMS trips out when using two batteries.
Is there anything I should be aware of when setting up the charge points for two batteries.
Thanks in advance.

Regards
Gary

Powerbrick + 12V 20Ah LiFePO4

powerbrick_12v-20ah-pro2-1-700.png (460.25 KiB) Viewed 4937 times

[Adrian Harris]

I can't see there being a problem if the BMS for one cuts in, it'll just isolate the battery and break the circuit. I prototyped a dual battery voltage monitor system for the LA batteries but haven't run it in the tank yet - must get on with that.

I've always used two chargers when using separate batteries. Ctek battery chargers have floating outputs, so I can charge the batteries whilst still wired together, though best practice would be to separate them before charging.

My Tiger has two 22Ah batteries lying nose to nose under the turret. I'll take a shot today as I need to get it out to work on the engine deck.

Adrian.

[Gerhard Michel]

Hi Gary,

please do NOT try to use a 2 channel charger when batteries are wired to each other! Most 2 channel chargers have connected minus poles. If you use separate chargers the batteries can be connected to each other. Using a built in BMS you may use simple and cheap chargers without balancing possibilities.

[Gary Richardson]

Hi Gary,

please do NOT try to use a 2 channel charger when batteries are wired to each other! Most 2 channel chargers have connected minus poles. If you use separate chargers the batteries can be connected to each other. Using a built in BMS you may use simple and cheap chargers without balancing possibilities.

Hi Gerhard

Thanks for the reply.
Sorry, I didn't make it clear that I am looking to get two chargers not one dual charger. I could get away with just one charger and do the batteries one at a time but that slows charging up if you get that perfect tanking opportunity. The internal battery BMS will do the balancing. I will do a bit of research into suitable chargers as well as battery telemetry, possibly using the FrSky FAS100 ADV.

Regards
Gary

[Donald Suttie]

Ctek also do a 24V battery charger,in some older threads i see one or two of them and that means you can use the supplied wire to charge both batteries at the same time

Donald

[Phil Markham]

Hi All,

I would like some advice please. My Tiger 1 has been running on 2 x 12v SLA batteries, I have recently removed the tank from storage where it has been for the past 5 years or so and the batteries are of coarse now useless. As someone who has no idea about LiFePO4 batteries but would like to take advantage of the newer technology and vastly improved running time I would like to know if it is just a case of swapping my old SLA batteries out and installing the new LiFePO4 battery (either 1 x24v or 2x 12v) or is some other piece of kit required to make these batteries compatible? Forgive my ignorance, this is really not my field of expertise at all

I understand that a different type of battery charger is also required but again i'm not sure what?

Thank you

[Stephen White]

Phil - short answer is it’s a direct swap, no extra kit require required. Do read the Knowledge Base topic though if you want to know more. For example because of the different discharge characteristics, you don’t really need the same capacity with LiFePO4. Do get a battery with a built in Battery MAnagement System. (Now sit back and wait for people to say you don’t need it). You do need a charger intended for the type -most reputable suppliers offer one within the price.

[Gerhard Michel]

Hi Phil,

in your special situation I would (exceptionally ) support Stephen's statement: no games, but a simple change SLA against LiFe (WITH built-in BMS), and you have a good chance to may use even your actual charger. All other solutions (like my usual preferation of 8 single LiFe cells without BMS) I would recommend for new models and for people who are willing to get familiar with handling the LiFE technology.

[Phil Markham]

Hi all,

Thanks for the advice.
Below is a picture of my charger and two sizes of batteries I am thinking of buying. My Tiger currently uses 2 of the larger size battery
167L x 176W x 126H (inc. terminals) but I can save 6kg in weight if I use the smaller batteries, any thoughts on this?

Are these batteries a good choice or is there a better SLA option?

Thank you

Two of these below

or two of these below

s-l500.png (215.12 KiB) Viewed 4582 times

[Steve Stuart]

The smaller double 22 Ah option is the simplest. It gives adequate run time and allows space in the hull for other equipment. The can be put upright or flat depending on how things are going to be fitted in. I have them flat to optimise space and to achieve a centre of gravity with the track centre, some thing that enhances the tanks operation no end.
Steve

[Phil Markham]

Thank you

Has anyone had any experience with these batteries? £80 for the pair delivered free to UK mainland. https://slkpower.com/products/batteries ... 5c12712#!/

SLK.jpg (18.13 KiB) Viewed 4516 times